I was astonished when I read NASA’s draft Environment Impact Statement for their mission to return samples from Mars. NASA are normally so reliable. Normally their work is well grounded in the best and most recent science, and they are also very open with the public, for instance sharing their images from Mars as soon as they receive them themselves.
But this was far from NASA’s usual standard, and full of mistakes.
Video:
They used cites to out of date papers without mentioning papers that overturned their results. This is an example, they use papers that say a BSL-4 laboratory is suitable for planetary protection and show no awareness of the ESF study which reduced the size limits for microbes from 0.2 to 0.05 microns. I mentioned the ESF study in my public comment on their plans in May but they still don’t cite it.
Are you aware of the ESF Mars Sample Return study (Ammann et al, 2012:14ff)? It said "The release of a single unsterilized particle larger than 0.05 μm is not acceptable under any circumstances”. This is to contain starvation limited ultramicrobacteria which pass through 0.1 micron filters (Miteva et al, 2005). Any Martian microbes may be starvation limited.
This 100% containment at 0.05 microns is well beyond capabilities of BSL4 facilities. Even ULPA level 17 filters only contain 99.999995 percent of particles tested only to 0.12 microns (BS, 2009:4).
, Comment submitted on May 15 th by Robert Walker to NASA’s first request for comments on their plans.
[bolding added]
They don't cite this major and important study in the draft Environment Impact Statement. Nor do they give any reason for for leaving it out. It is just not mentioned at all. They have a section with their response to public comments, and it isn't mentioned there either, and they show no indication that they ever saw my comment. This is a graphic I did which shows how major the change was and the reason for it. This is a scanning electronmicrograph of an ultramicrobacterium. Ultramicrobacteria by definition have a volume of at most 0.1 cubic microns. Some of them were shown to be viable after passing through the 0.1 micron nanopores shown in this image.
Then, often, the Environmental Impact Statement says one thing, but their planetary protection cite for that sentence says the opposite.
This is one of NUMEROUS examples. This is what they say in the DRAFT Environmental Impact Statement: 1–6
Existing credible evidence suggests that conditions on Mars have not been amenable to supporting life as we know it for millions of years (iMARS Working Group 2008, National Research Council 2011, Beaty et al. 2019, National Research Council 2022).
Click through to their most recent cite from 2022 and this is what you see:
It is all about searching for CURRENTLY habitable environments on Mars. Yet they use that to support their claim that existing credible evidence says Mars hasn’t been habitable for millions of years. How is that supposed to make sense?
Other times the cite they used says explicitly that it didn’t study the topic the EIS cited it for. This is an example, NASA’S EIS says, DRAFT Environmental Impact Statement: 1–6
The natural delivery of Mars materials can provide better protection and faster transit than the current MSR mission concept. ... First, potential Mars microbes would be expected to survive ejection forces and pressure (National Academies of Sciences, Engineering, and Medicine and the European Science Foundation 2019),
You expect that 2019 study to be about whether microbes can survive ejection forces and pressure when they are ejected from Mars.
Click through and the cite says explicitly it didn’t study this topic:
The SterLim team did not include any sterilization during Mars ejecta formation in its analysis because such investigations were not requested in its study’s statement of work.
Page: 26
Their cite also didn't look at the fireball of reentry, since it is a study of transfer from Mars to Phobos, which doesn’t have an atmosphere. Also the risk for invasive martian microbes is from any that CAN'T get here on a meteorite. Introduced starlings, which can’t cross the Atlantic cause hundreds of millions of dollars of damage in the US every year. The barn swallow can cross the Atlantic and was there already. Similarly, the invasive diatom "Didymo" can't get even from one freshwater lake in New Zealand to another by itself. The meteorites we got from Mars come from at least 3 meters below the surface of the dry high southern uplands where the air is thin enough for glancing blows to send rocks to Earth and at that depth the temperature is a uniform -70 C except for any geological hot spots. It is highly unlikely any metaphorical martian "starlings" in surface salty dirt even get into those rocks never mind survive transit to Earth. We have no samples of the Martian dust, salts, dirt or ice on Earth. I go into that here below
ALL the major cites on planetary protection which I checked were inaccurately cited and I’ll give many more examples and go into those in more detail.
By using cites in this mistaken way they concluded falsely that there is no real need to protect Earth from microbes from Mars and that they are just doing it as an “abundance of caution”. This is what they say in the DRAFT Environmental Impact Statement: 3-16
The relatively low probability of an inadvertent reentry combined with the assessment that samples are unlikely to pose a risk of significant ecological impact or other significant harmful effects support the judgement that the potential environmental impacts would not be significant.
This conclusion goes against ALL the Mars sample return studies for decades includng the 2009 National Research Council study they themselves cite. There are many of them, and they ALL agree that we DO need to protect Earth from Mars samples.
The risk is probably low but it’s like the risk of a fire in your house. You are very unlikely to get a fire but you still install smoke alarms. This is how the 2009 study by the NRC put it (page 48 5 The Potential for Large-Scale Effects)
"The committee found that the potential for large-scale negative effects on Earth’s inhabitants or environments by a returned martian life form appears to be low, but is not demonstrably zero"
They don't give an example but the Great Oxygenation Event is a natural example to use if photosynthetic life got from Mars to Earth in the distant past. I cover this below here
On the meteorite argument it says (page 48)
"Although such exchanges are less common today, they would have been particularly common during the early history of the solar system when impact rates were much higher....
Despite suggestions to the contrary, it is simply not possible, on the basis of current knowledge, to determine whether viable Martian life forms have already been delivered to Earth. Certainly in the modern era, there is no evidence for large-scale or other negative effects that are attributable to the frequent deliveries to Earth of essentially unaltered Martian rocks. However the possibility that such effects occurred in the distant past cannot be discounted. ... Thus it is not appropriate to argue that the existence of martian meteorites on Earth negate the need to treat as potentially hazardous any samples returned from Mars by robotic spacecraft."
Although the EIS cites the 2009 study, there is no mention of their cite's discussion of transfer on meteorites. Also, this conclusion isn't based on knowledge gained since 2009, which has added many MORE potential small scale and microhabitats on Mars for terrestrial or native life. Their mistaken conclusion is just based on a chain of incorrectly cited studies.
NASA do plan to use a Biosafety Level-4 facility to contain the samples but this approach is now more than a decade out of date. They didn’t cite the 2012 European space foundation study which reduced the size limit from 0.2 microns to 0.05 microns in just three years.
Even the ESF report is from a decade ago and much has changed in our understanding of Mars AND in our understanding of potential for small non terrestrial organisms in that time. NASA didn’t do the update to the size limits review which the ESF study says needs to be done periodically and is certainly needed before NASA can do an EIS on the topic, at least if they wish to explore the possibility of an unsterilized sample return.
This is how the 2012 ESF report explained its decision at the time (page 3):
The value for the maximum particle size was derived from the NRC-SSB 1999 report ‘Size Limits of Very Small Microorganisms: Proceedings of a Workshop’, which declared that 0.25 ± 0,05 μm was the` lower size limit for life as we know it (NRC, 1999). However, the past decade has shown enormous advances in microbiology, and microbes in the 0.10–0,15 μm range have been discovered in various environments. Therefore, the value for the maximum particle size that could be released into the Earth’s biosphere is revisited and re-evaluated in this report. Also, the current level of assurance of preventing the release of a Mars particle is reconsidered.
. Mars Sample Return backward contamination–Strategic advice and requirements
I found that even a decade after the ESF report, the technology doesn’t yet exist to contain samples at 0.05 microns with any of our current filters including experimental filters in laboratories.
I found several papers that could filter out most but not all viruses at this size from high pressure water. I found only one paper reporting 100% success with an experimental filter using carbon nanotubes doped with silver which only works to filter out particles from compressed water and has maintenance issues.
For airborne filters the best I found was 88% reduction with an experimental 6 layer filter. There are many papers about filter technology, but they typically focus on efficiency for filtering larger particles.
These electrospun nanofibre filters rely mainly on Brownian motion below 0.1 microns. The particles are far smaller than the gaps between the fibers, but many get deflected out of the air flow to hit the fibres by the random jostling from individual air molecules hitting them. See page 7 figure 5 and section 4.3. of the 2022 review: Diffusion Mechanism of Application of Electrospun Nonwoven Fibers in Air Filters.
I haven't yet found research into 100% containment at any size range for air filters. That's a decade after the ESF study. They can achieve high filtration efficiencies but they aren't aiming to reach the ESF study requirement that "The release of a single unsterilized particle larger than 0.05 μm is not acceptable under any circumstances”. I was unable to find any suitable sources to assess what would be feasible if they made the ESF study requirement an objective in air filter research.
My conclusion is, NASA's EIS needs to be stopped. Not the mission. The draft EIS. Also they need to look into ways to make sure they never do a draft EIS like this again with so many mistakes in it.
NASA could do a sterilized sample return which would retain much of the science interest and keep Earth 100% safe.
Otherwise they need a new size limits review (which may reduce the size limit to 0.01 microns if it decides ribocells are now plausible). Then based on the new decision on the size limit, we need some idea of the feasibility, cost and timescale for developing the technology for 100% filtration from the air at this particle size, before they could start on an Environmental Impact Statement based on containing unsterilized samples using air filtration.
Metaphorically NASA are building a house without smoke alarms or with ineffective smoke alarms. The risk is probably not high but this is a “house” for billions of people who don't know what is being done and have no role in the decision.
It is also a precedent for other missions. If NASA return samples in this way without a proper assessment of risks and precautions, other countries may well copy them and return samples more likely to contain life than these mainly geological specimens. NASA are likely to set a precedent for other nations.
Text on graphic: We need to install “smoke detectors” to protect Earth.
The risk of large scale effects from NASA’s mission is likely very low - indeed unlikely it returns life at all but it’s not demonstrably zero.
The risk of a fire to your house is also low.
We need the smoke detectors just in case. Especially for a “house” for billions of people.
Especially as we likely have many future missions like this from many countries.
Background graphics:
. Smoke detector.JPG - Wikimedia Commons
And this photo of a fire from the Los Angeles fire department, “Smoke alarm saves residents of a Bel Air home”
I found that NASA's EIS has a purpose and need section which is so narrowly defined that it excludes the reasonable alternative of a sterilized sample return. It does that by saying it is a need of the mission to return unsterilized samples for "safety testing". However I also found that the leel ofo contamination is so high that there will be no way to achieve a "safety assessment".
This is a reason often used to stop a project if the EIS defines a purpose and need so narrowly that it excludes reasonable alternatives. It is not permitted by a 7th circuit decision from the 1990s. So this puts the project in a fair bit of jeopardy potentially. For details see below . So this is yet another reason to stop the EIS appplication (not the project) to add and seriously consider reasonable alternatives like a sterilized sample return.
I also discovered that a sterilized sample return would achieve nearly all the geological science return for significantly less cost than their elaborate but ineffective precautions. Perseverance achieved levels of contamination of biosignatures and organics at 0.7 nanograms per biosignature per tube is very low for geology. However this is the equivalent of thousands of ultramiacrobacteria (at most 0.1 cubic microns or 0.1 picograms each) for each biosignature, all completely filled with just that molecule (e.g. glycine, DNA, etc).
This level of forward contamination of the sample tubes is far too high for astrobiology. Also because of "microbial dark matter" - the uncultivable unsequenced majority of microbes - we can't cultivate even most terrestrial microbes and most have never been sequenced . Even Perseverance's clean room samples turned up four species known only by a tiny fragment of the ribosome that are not closely related to any known terrestrial species. This isn't unusual. We can expect several such false positives from the sample tubes. There will be no easy way to prove the tubes don't contain martian life for their “safety assessment” with that level of contamination.
However this could be made into a mission of much greater astrobiological interest by sending sterile containers with the ESA fetch rover to return a scoop of dirt, ideally containing the brines found indirectly by Curiosity in Gale crater and likely present in Jezero crater, and a sample of dust and atmosphere all collected in STERILE containers. The arm for picking up the sample tubes could serve dual purpose as an arm to scoop up a small sample of dirt for astrobiologists and place it in a separate sterile container as for the Viking lander on the left of this image.
With this second alternative the geological samples would be returned to Earth sterilized and unopened as before so there is no need to split samples in orbit. The astrobiological samples could be sterilized too. If there is any present day life in the samples it could be recognized easily even after sterilization when returned in sterile containers. It would also help greatly with understanding the complex chemistry. The Viking results aren't yet fully understood and if it isn't life it might be complex prebiotic organic chemistry. We can study that far more easily with samples free of terrestrial contaminants.
However with this second alternative we could return the astrobiology samples to a safe orbit. Quarantine won't work to protect Earth. This seems to be new to my study so it's not yet peer reviewed but I expect this to pass peer review. You can't contain a crop disease with quarantine of human astronauts. I give the example of two Zinnia plants that died on the ISS due to disease of plants brought there in the microbiome of an astronaut.
This also happens to be an example of a mold that is rarely an opportunistic pathogen of humans but is usually symptomless, an example of the second issue I found. It's not possible to use quarantine to contain an opportunistic pathogen of humans if some humans are symptomless even if others die. Also no quarantine period could be long enough to contain unknown pathogens. Typhoid Mary was a lifelong symptomless superspreader of a human pathogen. I go into this in more detail later and in my preprint. My final example for quarantine is that if Mars has mirror life (not ruled out) it could be become part of the human microbiome, cause no symptoms, yet cause large scale effects on return to Earth. There are many other issues with quarantine but those alone rule it out as a way of protecting Earth - unless of course we know what we are protecting Earth from.
However astroboilogists have been trying for some time to send miniaturized life detection instruments to Mars. With all this work they have miniaturized life detection instruments to an extraordinary degree, especially in the last decade.. These could easily be used to study the dust, dirt and atmosphere remotely in a high safe orbit with no risk to Earth and with minimal forwards contamination of the collected samples. They can even send a fully miniaturized scanning electron microscope to Mars or a full end to end DNA sequencer from preparation all the way to outputting the gene sequence. The latency would be far less in a safe orbit above GEO. Meanwhile Ariane 5 can send over 6 tons to above GEO in one launch.
. Ariane 5: payload and geography open super-efficient path to GEO
This wouldn’t add hugely to the cost especially for NASA. Most likely universtiies would collaborate to pay for these missions to study the samples in orbit not NASA and the costs are incurred in the 2030s once the sample is already retured. This would make this a mission with far greater science return. It isn’t “mission creep” as these are samples that were descoped from Perseverance and that are in accord with its mission objectives.
Perseverance does have a copule of regolith samples
. NASA's Perseverance Rover Gets the Dirt on Mars
But these have nothing like the astrobiological return of a scoop of dirt or sample of dust for astrobiology as they aren't returned in sterile containers. Whether resturned sterilized or unsterilized they would be a major boost to astrobiology.
So I suggest two alternatives both of which keep Earth completely safe and without need to try to test the samples to see if they are safe, which is likely impossible to do.
- Return the geological samples as planned and sterilize everything - lower cost than their proposal, almost the same geological science return, and likely minimal or no effect on astrobiology as it’s not likely to return life even if it is present in Jezero crater in microhabitats OR
- Return the geological samples as planned, sterilized but add a bonus sample of dirt, dust and gas collected in STERILE containers for the astrobiologists, and return the astrobiological samples sterilized
- Return the gological samples sterilized and return the bonus astrobiological samples to orbit to study with miniature instruments such as the ones they designed to send to Mars.
2 and 3 greatly increase science value for astrobiology.
These three proposals can be achieved while keeping Earth 100% safe. If these are the only options considered NASA can do a simple environmental impact statement and with no need to do the size limits review. Also there is no need to develop technology to contain life at the required size limit, a technology which may well be unattainable even after a decade of research, especially if the review reduces the limit further to 0.01 microns.
With any action where all samples returned to Earth are sterilized, NASA just need to review methods for sterilizing the samples. This needs to look carefully at the potential for martian life more radioresistant even than radiodurans, the microbe that can live in reactor cooling ponds. Our terrestrial life seems to have evolved radioresistance as a biproduct of UV resistance while martian life would have had ionizing radiation resistance as a selection pressure for billions of years.
Also if nanoscale X-ray emitters are used during the voyage back from Mars, these are tuneable. We can search for frequencies or combinations of frequencies which are optimal for sterilizing life while minimizing the already small effect on geological science.
Do comment on the proposal yourself. They aren't getting many -public comments as the whole thing has had very little publicity.
I am confident they will re-examine this and do the proper procedures to protect Earth. I'm doing what I can to make sure it happens sooner rather than later, as it is a big expense to do it later, and you can all have your say in the public comments to help with the process.
You can click on the blue comment button at top left of this page to comment:
My latest comment is here:
You can get a good first impression of this article by looking at the graphics and reading the section headers. Then to drill down on any section of interest. I have added "skip to next section" links to make it easy to skip through the post section by section - and you can usualy use the back button on your browser to go back to the previous section (this also makes it possible to link to a particular section on the page).
Some of the most serious mistakes in this draft EIS (list from my preprint)
Skip to next sectionI could do this review quickly because I’ve been working on a paper specifically on planetary protection for NASA’s Mars sample return mission since 2020, which I plan to submit to astrobiology journals in the near future:
So I was already familiar with the literature on the topic. For more about my background see the end of this blog post.
Here are the main things I found, from the first page of the contents list of my preprint. As we’ll see soon, these mistakes are obvious, not subtle ones and they completely invalidate the EIS.
But let’s first start with a list so you can get an overview. I think you’ll agree, these are SO MANY SERIOUS MISTAKES.
- Draft EIS says (MISTAKENLY) Mars life can get to Earth faster and be better protected in meteorites than sample tubes - their cites don’t support this - their main cite is about transfer from Mars to its innermost moon Phobos instead of Earth - and didn’t look at sterilization during ejection from Mars
- Charles Cockell’s paper (which they don’t mention) said planetary exchange of photosynthesis might not be impossible but quite specific physical conditions and evolutionary adaptations are needed and the fireball of re-entry is the most important filter to stop photosynthetic life getting to Earth
- Draft EIS says (MISTAKENLY) existing credible evidence suggests Mars hasn’t been habitable for life as we know it for millions of years - their cite says that we need to search for current habitats in a seemingly uninhabitable Mars
- Draft EIS says (MISTAKENLY) that Jezero crater is too inhospitable for life to survive there – their cite from 2014 only studied capabilities for forward contamination by terrestrial life, and specifically says it didn’t study potential capabilities martian life might have (as needed for backwards contamination studies)
- Draft EIS says MISTAKENLY that the 2014 cite represents a consensus opinion within the astrobiology scientific community – even for forwards contamination it was not a consensus as it was overturned by a 2015 review commissioned by ESA and NASA which emphasized potential for microhabitats within apparently uninhabitable regions, and transport of life on dust
- Draft EIS says (MISTAKENLY) potential environmental impacts would not be significant – 2009 NRC study says risk of large scale effects appears to be low but not demonstrably zero, and they can’t rule out the possibility of large scale effects on the Earth’s biosphere from martian life in the distant past
- Potential for large scale effects should be re-assessed based on many new potential microhabitats on Mars both for Jezero crater and elsewhere on Mars - not known at the time of the 2009 report
- Draft EIS OMITS the 2012 European Space Foundation study which reduced the size limit to 0.05 microns from the previous value of 0.2 microns – a serious omission since containment at 0.05 microns is well beyond the capability of BSL-4 facilities
- The 2012 European Space Foundation study says its 0.05 micron size limit needs to be reviewed regularly – this alone is sufficient reason to halt this EIS process until the new size limits review is done
- NASA’s draft EIS has no mention of quarantine or other precautions for accidental release on Earth – just sterilization of the landing site
- All these inaccurate cites and omissions make the draft EIS easy to challenge in courts – and they didn’t respond to significant concerns raised by the public such as my own comment alerting them to the European Space Foundation study limit of 0.05 microns which is still not cited in the draft EIS
My preprint analysing it is here:
I will go into those in detail later in this blog post. But first let’s look at some solutions that keep Earth 100% safe. These are not mentioned in the draft EIS.
Before we do that we need to look at why NASA didn’t consider any alternatives that keep Earth 100% safe.
Draft EIS only presents No Action as an alternative to the proposal, even though there are alternatives which eliminate any possibility of harm to Earth’s biosphere while still retaining nearly all the science interest
Skip to next sectionThe draft EIS presents only one alternative to the proposed action, and that is no action.
No action naturally has many negatives for planetary science. But there are numerous other alternative actions.
The document mentions only three alternative that were presented via scoping comments.
This is what NASA’S EIS says, DRAFT Environmental Impact Statement: 4-1.
- Conducting sample analysis on the surface of Mars to determine the samples are safe prior to return to Earth
- Conducting sample analysis on the lunar surface to determine the samples are safe prior to return to Earth
- Conducting sample analysis in orbit on the International Space Station to determine the samples are safe prior to return to Earth
They all involved conducting the entire sample analysis somewhere else, on the surface of Mars, in lunar orbit or in a high or low terrestrial orbit and determine the samples are safe before returning to Earth.
However there is another alternative. That is to return sterilized samples for geological studies.
So why didn’t they consider this?
NASA didn’t consider these alternatives because the Environment Impact Statement said in its “Needs and purpose” section that the samples need a safety test. They then argue that this safety test can’t be done anywhere else except on Earth.
But a sterilized sample return is MADE safe by sterilization. So it doesn’t need an extra safety test.
This seems to be a reasonably clear case where the “needs and purpose” is so narrowly defined it excludes “reasonable alternatives” such as sterilization of all the samples which we’ll see can achieve nearly all the mission goals.
An environmental impact statement needs to look at alternatives - and the need and purpose should NOT be defined so narrowly as to exclude “reasonable alternatives” by Simmons v. U.S. Army Corps of Engineers
Skip to next sectionThis was decided in the U.S. Court of Appeals for the Seventh Circuit in Simmons v. U.S. Army Corps of Engineers. It is contrary to NEPA for agencies to
“contrive a purpose so slender as to define competing `reasonable alternatives' out of consideration (and even out of existence).”
In context:
When a federal agency prepares an Environmental Impact Statement (EIS), it must consider "all reasonable alternatives" in depth. 40 C.F.R. § 1502.14. No decision is more important than delimiting what these "reasonable alternatives" are. That choice, and the ensuing analysis, forms "the heart of the environmental impact statement." 40 C.F.R. § 1502.14.
To make that decision, the first thing an agency must define is the project's purpose. See Citizens Against Burlington, Inc. v. Busey, 938 F.2d 190, 195-96 (D.C. Cir. 1991). The broader the purpose, the wider the range of alternatives; and vice versa. The "purpose" of a project is a slippery concept, susceptible of no hard-and-fast definition.
One obvious way for an agency to slip past the strictures of NEPA is to contrive a purpose so slender as to define competing "reasonable alternatives" out of consideration (and even out of existence). The federal courts cannot condone an agency's frustration of Congressional will. If the agency constricts the definition of the project's purpose and thereby excludes what truly are reasonable alternatives, the EIS cannot fulfill its role. Nor can the agency satisfy the Act. 42 U.S.C. § 4332(2)(E).
…
Not least among the flaws — and the most glaring in hindsight — was the Corps' failure to consider reasonable alternatives. Judge Foreman deemed the environmental assessment "incomplete and flawed," and found no hint "that the Corps gave independent thought to the feasibility of alternatives."
…
The opinion of the district court is REVERSED and the case REMANDED with instructions to enter summary judgment for the plaintiffs and to vacate the permit.
“Vacate the permit” there means the project was not permitted to go ahead.
A properly drawn purpose and need statement should permit considering reasonable alternatives. By 40 CFR 1508.1(z)
Reasonable alternatives means a reasonable range of alternatives that are technically and economically feasible, and meet the purpose and need for the proposed action.
NASA’s purpose and need is too narrowly defined - it requires the samples to be returned to Earth for safety analysis - which prevents them considering a sterilized sample return even though a sterilized sample return wouldn’t need a safety analysis
Skip to next sectionIf we look at the “purpose and need” it says that the samples must be returned to Earth to a biosafety laboratory for a “comprehensive sample safety assessment”.
This is what NASA’S EIS says, DRAFT Environmental Impact Statement: 3–3
An important aspect of this is that many critical measurements can only be done on samples that have been through intricate sample preparation processes, and most of those processes are not able to be automated.
These same principles regarding the importance of using terrestrial laboratories to enable the best scientific return also apply to the care and attention to detail that would be required to conduct a proper and comprehensive sample safety assessment in a proposed SRF.
So the purpose and need section says that the samples have to be returned to Earth to do a comprehensive sample safety assessment.
This narrowly defined “needs and purpose” prevents them from considering the possibility of sterilizing the samples on the way back from Mars, because they wouldn’t be able to do this safety assessment on Mars.
If we check the submitted alternatives, this is indeed the argument they use to rule out the alternatives to “no action” proposed during scoping. If we go to section 2–3 (Alternatives considered but not carried forward) it sayss, DRAFT Environmental Impact Statement: page 2–24:
Alternatives must be able to accommodate the equipment required to conduct the proper analysis to meet MSR Campaign objectives (which include not only science but also a properly rigorous assessment of the biological safety of the samples).
So they use the narrow scope of the needs and purpose to exclude any alternative that doesn’t permit a safety assessment of the sample to detect if there is life in it or not before it is returned.
But if I understand right, they shouldn’t define the purpose and need so narrowly.
Even if this was permitted, it is ethically questionable to use this technical method to remove any possibility of considering an alternative that keeps Earth 100% safe. But I don’t think it is legally permitted either.
So for instance, they should consider a sterilized sample return. This would preserve almost all the geological interest of the study by their own assessment. They don’t do this, the only alternative to return to a biosafety laboratory on Earth is “no action”.
Another alternative action is to return a sterilized geological sample return can be combined with continuing life science studies either on the surface of Mars, on the Moon or in high or low orbit on samples that are left in orbit in order to keep Earth safe and never returned unless proven safe.
In that case there is no need for the safety assessment for the samples in orbit either because they are never returned to Earth unless proven safe.
As we’ll see, although in the best case scenarios life from Mars may be safe for Earth, there isn’t any guarantee that a sample that contains viable life will ever be proven safe to contact Earth’s biosphere unsterilized in worst case scenarios (such as mirror life).
If it is not safe for the life to contact Earth’s biosphere, the simplest solution is to keep it in orbit. Those are two reasonable alternatives which we’ll look at in detail.
It seems clear that the EIS must consider actions that keep Earth’s biosphere 100% safe in addition to its current alternatives of BSL-4 laboratories and no action:
I am not a lawyer and I welcome comments from lawyers on whether my understanding here is correct.
How would they prove the samples are safe on Earth? Permitted levels of biosignatures from contamination by terrestrial life guarantee false positives
Skip to next sectionThen finally, there are issues with the whole idea of proving the samples safe on Earth too.
In the section "Planetary Protection in the Sample Receiving Facility" in the DRAFT Environmental Impact Statement: pages 2-16 to 2-17 they cite Kiminek.
Ultimately, the SSAP Working Group findings, through an external independent peer reviewed process, will evolve over time as knowledge of sample constituents evolves and scientists identify certain requirements and protocols that should be implemented to ensure sample safety throughout the sample management, handling, and curation process (Kminek et al. 2022).
But their cite there says that it is practically impossible to predict the effect of introducing life in new environments. So the only safety testing they can do is to check if there is extant life there at all:
During the Working Group’s deliberations, it became clear that a comprehensive assessment to predict the effects of introducing life in new environments or ecologies is difficult and practically impossible, even for terrestrial life and certainly more so for unknown extraterrestrial life.
To manage expectations, the scope of the SSAF was adjusted to evaluate only whether the presence of martian life can be excluded in samples returned from Mars. If the presence of martian life cannot be excluded, a Hold & Critical Review must be established to evaluate the risk management measures and decide on the next steps.
From table 3 on the page S-200 they do that by checking for biosignatures and can only say there is no life if they find no biosignatures and even then need to consider martian life that may not be obvious with tests for terrestrial biosignatures.
We’ll see that Perseverance’s permitted levels of contamination, though low for geologists, are so high for astrobiology that it is guaranteed to generate false positives. They permit enough DNA or of any paraticular amino acid or any other biosignature to completely fill thousands of ultramicrobacteria with just that biosignature.
Their measurements to test success of their procedures to reduce contamination suggest they achieved a maximum of
- 8.1 nanograms of organics per tube
- 0.7 nanograms for each of the biosignatures they tested (e.g. DNA)
- 0.00048% chance of a single viable microbe per tube
– this means a 0.02% chance that at least one tube has a viable terrestrial microbe in it.
From: table 6 of . Mars 2020: mission, science objectives and build. In Systems Contamination: Prediction, Control, and Performance 2020
That is impressively low for geological studies of past life. But it is impossibly high for astrobiological studies.
Text on image: Example of how design decisions for Perseverance were based on engineering and geology rather than astrobiology.
This tube was used to collect the first sample from Mars.
For a geologist, it is exceptionally clean, at most 8.1 nanograms of organics and at most 0.7 nanograms per biosignature.
For an astrobiologist, 0.7 nanograms per biosignature is enough to fill at least 7,000 ultramicrobacteria with just that biosignature, e.g. glycine, or DNA (maximum volume 0.1 cubic microns per ultramicrobacteria)
Astrobiologists need 100% clean sample containers with no organics. Their life detection instruments designed for in situ searches on Mrs can detect a single amino acid in a gram.
For engineers, sterilization would add an extra mission critical failure point because they would need to open the sterile container for the tube on Mars.
Sample tube photo from: Perseverance Sample Tube 266
So, it will likely be impossible to prove that there is no life from Mars in the tubes using biosignatures.
Most terrestrial microbes can’t be cultivated in the laboratory so it’s not possible to test for viable martian life by trying to cultivate it - and most haven't been sequenced - Perseverance clean room samples turned up many species only known by their ribosome and 4 with a ribosome that didn't resemble any known terrestrial species (this is not unusual)
Skip to next sectionIt’s not possible to test for viable life from Mars by trying to cultivate it as most microbes on Earth can’t be cultivated either since we can’t duplicate the conditions they need. Most microbes even of terrestrial life are uncultivable, can't grow in the laboratory though they grow perfectly well in the wild often in very difficult hostile conditions.
It's frustrating for microbiologists, there is their microbe growing in very difficult conditions in the wild but they can't get it to grow, say, on an agar solution, turns its nose up at their best nutrients in the lab.
The main reasons microbes can’t be cultivated are:
- They may depend on other microbes for their amino acids and even nucleotides, they may not have much by way of ribosomes to make proteins and some use strands, phyla to extract nutrients from other bacteria in biofilms.
- Others have very long generation times of six months or more, which makes it hard to sequence in a laboratory. This is very relevant to Mars. In those cold conditions it’s possible some have generation times of years to centuries or more.
- Others only survive in nutrient poor situations. They do very well in natural conditions but when you put them in a laboratory on an agar solution they die quickly. Again this may be very relevant to Mars given that nearly all habitats will be nutrient poor.
- Some produce hydrogen as a biproduct and they depend on other microbes to remove the hydrogen or they die.
. The bright side of microbial dark matter: lessons learned from the uncultivated majority.
So we can’t test by trying to cultivate the life. Then you might try to test if it is from Earth with gene sequences. We can detect known sequences in that way. But sadly most microbes are NOT sequenced and we have no idea what their sequence is.
A 2021 study of the clean room used to assemble Perseverance turned up many microbes only known by their ribosomes and 4 of the species found had ribbosomes that didn't match any peviously known terrestrial microbe.
I cover this in my preprint about the draft EIS in the sections:
- Problem of microbial dark matter - we don’t have a census even of all the RNA and DNA that we sent to Mars in the Perseverance sample tubes - which likely contain many genes from species we haven’t yet sequenced
- Many entire phylae are only known through a small rRNA fragment of their protein factory - specifically the rRNA component of the 16s ribosome subunit
- The Perseverance clean room had many uncultivable species, 36 out of the 41 species identified by their 16s ribosome subunits were found in only one location - and 4 had ribosomes that didn’t closely resemble any previously known ribosome
- If this level of diversity can be generalized to the tubes, each sample tube could contain unique 16s subunits not found in any of the other sample tubes and out of 38 sample tubes three or four of them may contain subunits that don’t closely resemble any ribosomes so far known on Earth, although originating from Earth
From the previous section, we won’t be able to test for life by looking for biosignatures.
So how are astrobiologists expected to prove the samples are safe?
As stated in the NASA guide Planetary protection provisions for robotic extraterrestrial missions
A "false positive" could prevent distribution of the sample from containment and could lead to unnecessary increased rigor in the requirements for all later Mars missions.
. NPR 8020.12D, Planetary Protection Provisions for Robotic Extraterrestrial Missions.
There seems a significant possibility of a false positive here, which could delay certifying the samples as safe for Earth, or make it necessary to sterilize all samples returned indefinitely. Indeed, it is hard to see how these samples could be certified by experts to be free of any Martian life.
If the samples can’t be tested in any way to see if they are safe, that takes away this need to return them to Earth for testing.
Because of the decision to not sterilize the sample tubes, the geology samples will just have to be kept contained or sterilized indefinitely - or until we know more about whether there is life on Mars in other ways.
The only way to perhaps obtain samples we know don’t have martian life in them is to use 100% sterile containers. Those samples then could be tested properly to see if there is life in them.
Even with sterile containers, given how sparse present day life is expected to be on Mars, it might still be problematical to prove that there is NO life in them. The question will be, could there be a single viable cell or spore or propagule in a section of the sample that hasn’t been examined yet?
We might later be able to deduce that the samples are lifeless, as our understanding of Mars develops, but it would be challenging to prove this by direct measurement of biosignatures in the samples.
From this it seems that unlike the situation for the lunar samples, NASA and ESA need to plan for the Martian samples to be sterilized before distribution to normal laboratories for the indefinite future.
For all these options, most likely the end result of any legal process that looks into this thoroughly will be that samples are only be permitted to be handled unsterilized in laboratories equipped to contain 0.05 ultramicrobacteria - or whatever the final size limit is after review, 0.001 microns for ribocells if that’s considered possible - until we know more about Mars and whether there is any potential for viable native life in samples from Jezero crater.
This mission “as is” is just a technology demo for astrobiology - chance it returns anything impacted by sterilization is low - complete sterilization is an easy way to keep Earth 100% safe and retain just about all science value - and at far less mission cost
Skip to next sectionIt’s clear from these permitted level of contamination in the tubes that this is a mission designed around geological rather than astrobiological priorities. We do have the technology to achieve 100% sterile containers.
Engineers were concerned that the container would have to be kept enclosed and only opened after launch and the engineers worried that it would add one extra failure point. If the sterile container didn’t open it would be mission critical and no samples could be taken.
1. A fully sterilized sample return. This achieves just about all geological goals - and astrobiologists use little since the mission as currently conceived is little more than a technology demo for future samples of more astrobiological interest
Skip to next sectionAstrobiologists lose little as it is little more than a technology demo for a future mission with more interesting samples.
Imagine if a geologist was given a sample but didn't know if there were any rocks from Mars in it? Also imagine it as so many rocks from Earth it will be impossible to pick out which ones came from Mars if any did. How could you do geology in that situation?
Analogy for the organics returned from Mars by the rover - suppose you have a collection of rocks from Mars - great! But now you are told most were taken to Mars on your rover and there might not be even one Martian rock in it. Not so great! How are you supposed to do geology? And now amongst all those rocks there may be a small piece of amber with an insect trapped in it - but your rover can’t spot insects trapped in amber, sent lots of dead insects in amber from Earth to Mars, and most likely none of the organics returned contain any life [insects in this analogy) but were brought there via comets, interplanetary dust, or asteroids, or made locally, or degraded beyond recognition (expected situation even with past life and present day life on Mars).
This is why astrobiologists want to do in situ studies on Mars first and are interested in dust or dirt collected in STERILE CONTAINERS
Background images: Sand Grains
and: Gondwana amber
Levels of terrestrial biosignatures in the sample tubes though low by geological standards, are so high by standards of biology, astrobiologists would not detect the biosignature of thousands of ultramicrobacteria (10,000 to a nanogram) or millions of hypothetical early world ribocells.
2. Add 100% sterile containers to the Orbital Sample Container
Skip to next sectionUse those to capture a sample of dust, and gas using a miniature compressor similar to the one used by Moxie, and collect a scoop of dirt ideally containing the perchlorate salts that form the brines Curiosity discovered at night.
Here is how we can capture the dust sample. This device is very small - the authors talk about the possibility of fitting it inside an extra sample tube sent to Mars.
First it uses the getter to remove evolved gases from the container wall. Then it closes one microvalve and opens another to get an atmospheric sample. Finally it closes both microvalves to the gas container and opens the vent to run more atmosphere through the compressor to collect dust in the filter
Assuming a volume of, say, 50 cc of dust, and a dust density of 0.5 grams per cc, it could return up to 25 grams of dust.
With a larger 1 liter container, the compressor could return 100 liters or more of Martian atmosphere compressed to Earth’s atmospheric pressure which would be about 0.2 grams of atmosphere. That is enough for very sensitive analysis for biosignatures.
We can detect life from the Gobi desert in Japan. If there is distant life on Mars it doesn’t need to be very productive to be detected in this way. I did a rough calculation in my original preprint.
- Searching for distant inhabited habitats on Mars through presence or absence of one originally living cell per gram – a rough first estimate assuming uniform mixing throughout Mars for a first estimate requires life to cover between 114,000 and 1,140 square kilometers with densities of life in the dust similar to an Antarctic RSL analogue in cell count, but less than a tenth of a square kilometer if any reach a billion cells per gram – these figures can be higher if any source habitats with high densities of cells are closer to the rover with uneven mixing
Then the dirt is of great interest to astrobiologists.
- Could native martian life exploit the brines found by Curiosity? Will go into those later in this blog post - they might be potentially habitable by microbes in a biofilm or martian life with capabilities terrestrial life doesn’t have
- Were the Viking labelled release experiments the result of life or complex chemistry? Either way we need to know to help look for life more intelligently. It’s not yet fully explained as chemistry, especially the offset of 2 hours of the peak of evolved gases after the peak of temperature every day - which is usually a clear signature of life processes.
Also, even if Mars turns out to be completely free of life, it is of huge value for the chemistry of a planet that never developed biology. I go into that in my
- A prebiotic Mars, lifeless for billions of years, could still develop protocells, naked genes, Ostwald crystals etc – theorized forms of “almost life” and life precursors of great interest to us - value of sterile containers to sample potential uninhabited habitats
If what Viking found wasn't life it could give a window into complex pre-biotic chemistry.
The dirt has to be returned in a sterile container. But this is only mission critical for astrobiology - the geology samples in their sample tubes won’t be affected if the astrobiology containers can’t be opened on Mars.
This shows the dirt just placed on a plate on top of the sample tubes. But in reality it needs to be in a sterile container placed on top. It could be just placed like this as a last resort if the container won’t open. But that would be of far less astrobiological value.
If those were all returned in sterile containers it would be of far more interest to astrobiology.
So then the dirt, dust and atmosphere can be studied in a safe orbit remotely. While the geological samples are just sterilized and returned to Earth.
Text on graphic:
How to keep Earth 100% safe with minimal impact on science or cost – technology doesn’t exist to contain ultramicrobacteria.
So we can
1. sterilize all samples or
2. check for life first - to do this, return samples to a safe orbit above GEO to study remotely with miniature instruments like those designed by astrobiologists to search for life on Mars.
With 2. we can return sterilized sub-samples from the orbital facility immediately.
In 2, a return to the ISS doesn't break the chain of containment with Mars and COSPAR decided the Moon must be kept free of contamination for future astronauts and tourists. Above GEO solves both these issues.
By NASA regulations, build can't start until technology is decided. Build estimate: 9+ years + 2 years to train technicians.
Earliest date ready: 2023 + 11 = 2034
However, the technology doesn't exist yet for the 2012 European Space Foundation requirement of 100% containment of 0.05 micron particles even a decade later. This limit may also be reduced further on review.
Mars may resemble Earth's coldest driest deserts: small niches for life adapted to extreme conditions, perhaps habitable at microbial scales only.
Earth is protected from a Mars sample return by numerous laws to protect Earth's biosphere that didn't exist in 1969.
Solution 2: study in a safe orbit above Geostationary Earth Orbit (GEO) first.
Humans never go near the satellite.
Samples stay above GEO.
No risk to Earth's biosphere.
Astrobiologists study samples in orbit much as they would do controlling a rover on Mars.Sterilized subsamples can be returned immediately.
This is totally safe by:
a. return sterilized geological samples to Earth
b. return the unsterilized scoop of dirt, dust and atmospheric gases to an orbital laboratory where they are studied remotely much like using a rover on Mars but with almost zero latency, using miniature life detection instruments. Humans never go anywhere near it.
Astrobiologists have exquisitely sensitive miniature instruments now that they could easily send to an orbital laboratory to study the astrobiological sample safely - much in the same way they originally planned to send them to Mars for in situ studies
Skip to next sectionThese extra samples wouldn’t be guaranteed to return present day life, far from it. But they would give a first indication. We will only find life by looking for it and for microbial life we need to be able to test samples that may or may not have life in them to find out if there is life there. We can’t make progress if the aim is only to send life detection missions once you know already that there is life there. It’s very unlikely we find life that can be recognized without instruments to search for life.
If life is very abundant by Martian standards, perhaps as much as one viable cell or even dead cell per gram of surface dust or dirt, astrobiologists have miniature instruments sensitive enough to detect this which they could send to the orbital laboratory. Their most sensitive instruments proposed for in situ searches on Mars can detect a single amino acid in a gram.
Incidentally they also have miniaturized scanning electron microscopes, ultra high power optical microscopes that go beyond the 0.2 micron optical resolution limit using near field imaging, holographic 3D microscopes that can be refocused after the image is returned to Earth, instruments that can do complete gene sequencing from sample collection all the way to results, and many more, all of which could be fitted into a package to send to Mars of a few kilograms.
- Report of the Europa Lander Science Definition Team - describes many instruments including super-resolution microscopes
- Miniature variable pressure scanning electron microscope for in-situ imaging & chemical analysis
- SETG: nucleic acid extraction and sequencing for in situ life detection on Mars.
- full end to end gene sequencer from collection to analysis. - Searching for Organics in a Nibble of Soil - can detect a single amino acid in a gram
- A submersible, off-axis holographic microscope for detection of microbial motility and morphology in aqueous and icy environments
- lets you refocus on the microbe after the image is returned to Earth using a holographic image.
So they have plenty of instruments they could send to orbit to examine the samples, and there is a major advantage that it is far easier to keep an orbital satellite sterile and limit forward contamination.
I cover this in my original preprint in the section:
- Modern miniaturized instruments designed to detect life in situ on Mars - could also be used to examine returned samples in an orbital telerobotic laboratory
3. 100% safe lab on Earth?
Skip to next sectionThe basic idea is to return the unsterilized sample inside a titanium sphere. This much we can do and it would be safe, there wouldn’t be any risk to Earth from a sample inside a titanium sphere. We could even do end of experiment sterilization without opening it by simply heating it up to 300 C and keeping it at that temperature for hours or weeks as needed.
The issue is, how can we then get it out of the sphere with 100% safety to study and what kind of facility could contain it?
A sample return in a titanium sphere would be totally safe, but how then do we open the sphere? Top right image shows a titanium sphere that survived re-entry. Top left image shows Pandora trying to close the box that she opened in the Greek legend.
Main image - Genesis return capsule on the ground after it crashed
NASA, 2005, NPR 8020.12D, Planetary Protection Provisions for Robotic Extraterrestrial Missions.
Top left, Opening Pandora’s box
Church, F.S., n.d. Opened up a Pandora's box
Top right - space ball after re-entry - probably from the equipment module of Gemini 3, 4 or 5.
Daderot, 2017, Oregon Space Ball, probably from the equipment module of Gemini 3, 4, or 5 mission, titanium
So the next step is that the sphere is brought to the facility, protected as for a “black box” flight recorder during the transit. This is built inside a former nuclear bunker, It is also built inside a large oven for end of facility lifetime complete sterilization, in case something is returned that can’t be permitted to make any contact with Earth’s biosphere, like mirror life.
Finally instead of a conventional airlock it has two airlocks at positive air pressure which are only connected via sump filled with vacuum stable high temperature light oil which is kept at 300 C and irradiated with ionizing radiation., That should keep in even mirror life nanobes
To make this sketch I use the LAS fully robotic floor plan for a Mars sample receiving facility placed inside an oven for end of laboratory lifetime sterilization of the facility and accessed via two airlocks and a sump for 100% containment of even mirror life nanobes.
Text on image: Built inside former nuclear bunker for protection from accidental damage such as plane crashes
Laboratory built inside oven for sterilization at 300°C at end of life of facility
Sump
Inner airlock, outer airlock
Sketch for 100% containment of mirror namobes etc. Sump kept at 300 °C filled with Pentaine X2000 oil. Both airlocks and sump continuously radiated with X-ays and ionizing radiation and sterilied with CO2 snow. Both airlocks +ve pressure, inlets sealed during airlock cycles.
Sketch of telerobitic facility Credit NASA / LAS, Hsu, 2009, Keeping Mars Contained,
Photo of Cultybraggan nuclear bunker
Clark, 2009, Cultybraggan nuclear bunker
The studies would have to be done telerobotically. I’d be interested in thoughts from engineers as to whether this is feasible. This might permit a very fast legal process as it would hopefully be clear to everyone that it will be safe.
The build of the facility could be started right away with confidence that it will be considered suitable when finished. Congress would need to approve the build as it does with all major funding requirements.
This would be a big upfront expense. But if we don’t do it now, we might do it in the future if we find life on Mars or elsewhere that can NEVER be returned safely to Earth. I look at one such example in my preprint and will look at it more below. Mirror nanobe life. I found a wide range of scenarios from life that couldn’t establish itself on Earth at all, or would be harmless, or even beneficial, an enhanced Gaia where Earth’s deserts and oceans become more productive of life, all the way through minor nuisances like algal blooms and clogged waterworks or mouldy food in freezers to opportunistic pathogens of humans, crop diseases and large scale impacts on our biosphere.
So, depending on what we find on Mars we may well not need to take any precautions. But we may at the other end of the range never be able to return Martian life safely to Earth. We need to know which it is.
If we can never return life safely, perhaps something based on this design could be a way to keep Earth 100% safe while also permitting the samples to be studied on Earth.
NASA's proposed action can only get approved if never challenged in the courts - if nobody challenges it this time, the presidential directive to consider large scale effects at the end of all the other legal processes will surely strike it down
Skip to next sectionThe only way this gets approved is if nobody challenges it. If NASA do get it approved, it will surely fall apart as soon as an uninvolved expert looks at it.
If they get it through the NEPA / EIS process, it will be stopped by the presidential directive. All that matters is if it could be reasonably expected to result in domestic or foreign allegations of major or protracted effects.
“It should be understood that experiments which by their nature could be reasonably expected to result in domestic or foreign allegations that they might have major or protracted effects on the physical or biological environment or other areas of public or private interest, are to be included under this policy even though the sponsoring agency feels confident that such allegations would in fact prove to be unfounded.
So this directive requires the president to examine the project even if the agency thinks there is no risk of harmful effects from the action. That’s the point where it will fall apart if not before.
But hopefully this won’t get that far.
Some of the mistakes need some spade-work to see they are mistaken - but some are obvious
Skip to next sectionFor some of these things you need to check their cites. This can be hard to do as they sometimes link to an entire book of hundreds of pages without page or chapter numbers and without quotes.
A couple of them are even harder to check as you need to know they have left out an important later cite that proved the conclusion of their earlier cite to be mistaken. That sort of mistake is hardest to detect if you aren’t familiar with the literature.
I will need to explain those to you.
But some may be obvious already. Take the very first one in the list:
Draft EIS says (MISTAKENLY) Mars life can get to Earth faster and be better protected in meteorites than sample tubes
Skip to next section- their cites don’t support this - their main cite is about transfer from Mars to its innermost moon Phobos instead of Earth - and didn’t look at sterilization during ejection from Mars
This is what NASA’S EIS says, DRAFT Environmental Impact Statement: 3–3
The natural delivery of Mars materials can provide better protection and faster transit than the current MSR mission concept.
How can that be right? You and I couldn’t get from Mars to Earth on a meteorite. We couldn’t fit in a sample tube either of course, but could fit in a spaceship and a sample tube with a little bit of Martian atmosphere is not unlike a spaceship for a microbe.
To take an everyday example, barn swallows can cross the Atlantic, as indeed, many birds can do. They aren’t an invasive species in the USA because they got there by themselves.
What matters for invasive species are the ones that CAN’T get across the Atlantic, like the starlings.
Some microbes may be able to get from Mars to Earth - what matters for invasive species are the ones that can’t.
Barn swallow - can cross Atlantic
Starling - invasive species in the Americas
Didymosphenia geminatum. Invasive diatom in Great lakes and New Zealand, can’t even cross oceans.
Starling photo from: Starling - Flickr - TrotterFechan.
Barn swallow photo from A Barn Swallow in Flight
Didymosphenia geminata (Lyngb.) from: Species Profile - Didymosphenia geminata
Starlings are a problem species in the USA and cause a lot of damage. European Starlings
So we need to ask instead
“could there be ANY microbes on Mars that can get here more easily in a sample tube?”
Well you do get invasive microbes. Fresh water diatoms can’t survive in the sea. So how can they cross the Atlantic? It turns out that indeed they can’t and there are invasive fresh water diatoms that cause problems in the Great Lakes and New Zealand.
This is an example sign in New Zealand warning sailors about the risk of carrying didymo to another lake in New Zealand.
Text on sign: Your boat may now be carrying didymo. Please clean using approved methods. Protect our waters …
Image from: Didymo signage on Waiau river.jpg - Wikipedia
As you can see Didymo can’t even move from one lake to another in New Zealand without help from humans carrying it on wet gear. There is no way it could travel between planets. There are salt water diatoms too. But they couldn’t travel between planets on meteorites either. If there are diatoms on Mars they have evolved independently and can’t be directly related to terrestrial diatoms.
I cover this in my preprint about the draft EIS in the sections:
- Example of fresh water diatoms that can’t cross oceans on Earth
- We might even find diatoms on Mars – either preserved in gypsum, or perhaps living in the lakes our orbiters found beneath the polar ice
So, would a microbe adapted to microhabitats on the surface of Mars, living in the dirt, brines, or just beneath the crust of a rock, or in pores in salt, be more like the starling or the barn swallow?
There might be reason to suppose it would be more like the starling.
First, how is the dust, ice or salt going to get into the rock headed for Mars? Wouldn’t an asteroid impact just scatter the dust and salts in the atmosphere and melt the ice? The answer is yes. We don’t have any samples of Martian dust, salts, or ice.
That problem becomes especially acute when you discover that the meteorites we have from Mars all come from at least 3 meters below the surface in the very high dry southern uplands where the air is very thin. Also modelling shows that the smaller impacts into modern Mars can’t throw up surface materials at escape velocity.
I cover this in my original preprint in the section:
- Could Martian life have got to Earth on meteorites? Our Martian meteorites come from at least 3 m below the surface in high altitude regions of Mars
So where did NASA’s EIS get the idea that a microbe is better protected and can get here faster in a meteorite than a sample tube?
They used a study on the ejection of meteorites from Mars to its innermost moon Phobos. There are major differences here
- ejection velocity is far less to get to Phobos than to get all the way to Mars, so there is less shock to harm life.
- Phobos doesn’t have an atmosphere so there isn’t any fireball of re-entry.
But it’s far worse than that.
This is what NASA’S EIS says, DRAFT Environmental Impact Statement: 1–6
First, potential Mars microbes would be expected to survive ejection forces and pressure (National Academies of Sciences, Engineering, and Medicine and the European Science Foundation 2019),
You expect that 2019 study to be about whether microbes can survive ejection forces and pressure when they are ejected from Mars.
Click through and the cite says explicitly it didn’t study this topic:
The SterLim team did not include any sterilization during Mars ejecta formation in its analysis because such investigations were not requested in its study’s statement of work.
Page: 26
Also, because it was a study of transfer of life from Mars to Phobos it naturally doesn’t look at the fireball of re-entry to Earth, because Phobos doesn’t have an atmosphere. But for some forms of life, especially photosynthetic life, that’s the main thing stopping it getting here.S
Charles Cockell’s paper (which they don’t mention) said planetary exchange of photosynthesis might not be impossible but quite specific physical conditions and evolutionary adaptations are needed
Skip to next section- and the fireball of re-entry is the most important filter to stop photosynthetic life getting to Earth
Charles Cockell looks at Chroococcidiopsis, a blue-green algae that is astonishingly resistant to UV, desiccation that can remake its DNA even when chopped to pieces by ionizing radiation, that can live almost anywhere on Earth from the hottest driest deserts to Antarctica, tropical reservoirs, or even over 100 meters below the sea level (it has many alternative metabolic pathways that let it survive without light). It’s also one of the top candidates for an Earth microbe that could survive on Mars.
Yet he concluded that Chroococcidiopsis would find it very hard to get from Mars to Earth. This very versatile polyextremophile still can’t do it easily.
Charles Cockell concludes that though some shock resistant life can be ejected from Mars and survive, that most photosynthetic life can’t get to Earth from Mars in this way on present day Mars though he leaves open the possibility that it could get here in unusual circumstances.
QUOTE Few ecological dispersal filters are completely effective. Each of the filters described above could be survived on account of specific physical factors or evolutionary innovations.
He found that it could survive ejection from Mars but only at the lower end of the range. Chroococcidiopsis doesn’t form spores and that makes it far harder for it to resist the shock of ejection from Mars than other hardier spore forming microbes.
...In the case of ejection from the planetary surface, the experiments with Chroococcidiopsis sp. show that even these vegetative cells could survive shock pressures at the lower end of that documented in Martian meteorites (∼5 GPa).
To put this in context just about all the meteorites in our collections have ejection shock pressures larger than 5 GPa. Normally 15 GPa or larger. But from modelling about 1 in 50 should be less than 1 GPa.
Unlike the draft EIS, Cockell refers to planetary ejection as a “potentially strong dispersal filter” - many of the microbes would be killed by ejection. But at lower levels then they can be survivable.
... Thus, although planetary ejection is shown experimentally to be a potentially strong dispersal filter, these same experiments show that shock pressures close to those required to achieve escape velocity, at least for Mars-like planets, can be survived even for vegetative phototrophs without special protection.
But for those that survive the shock of ejection, then there’s the fireball of re-entry. It’s going to be hard for any photosynthetic life to survive that as they would be living on the surface or else maybe in cracks but still within reach of plasma that would get deep inside the meteorite.
... The dispersal filter of atmospheric transit is the most effective dispersal filter for photosynthesis.
... Thus, the planetary exchange of photosynthesis might not be impossible, but quite specific physical situations and/or evolutionary innovations are required to create conditions where a photosynthetic organism happens to be buried deep within a rock during ejection to survive atmospheric transit.
There isn’t anything here to support the thesis of the draft EIS that it is easier for Martian microbes to get to Earth on a meteorite than in a sample tube:
The natural delivery of Mars materials can provide better protection and faster transit than the current MSR mission concept.
Chroococcidiopsis is an example that shows that a species can be returned via a sample return far more easily than it could get here on a meteoroid ejected from Mars.
Let’s look at the next big mistake:
Draft EIS says (MISTAKENLY) existing credible evidence suggests Mars hasn’t been habitable for life as we know it for millions of years
Skip to next section- their cite says that we need to search for current habitats in a seemingly uninhabitable Mars
This is what they say in the DRAFT Environmental Impact Statement: 1–6
Existing credible evidence suggests that conditions on Mars have not been amenable to supporting life as we know it for millions of years (iMARS Working Group 2008, National Research Council 2011, Beaty et al. 2019, National Research Council 2022).
Click through to their most recent cite from 2022 and this is what you see:
Let’s look at the next one:
Draft EIS says (MISTAKENLY) Jezero crater is too inhospitable for life to survive there
Skip to next section– their cite from 2014 only studied forward contamination by terrestrial life, and specifically says it didn’t study potential capabilities for Martian life (as needed for backwards contamination studies)
This is what they say in the DRAFT Environmental Impact Statement: S-4
Consensus opinion within the astrobiology scientific community supports a conclusion that the Martian surface is too inhospitable for life to survive there today, particularly at the location and shallow depth (6.4 centimeters [2.5 inches]) being sampled by the Perseverance rover in Jezero Crater, which was chosen as the sampling area because it could have had the right conditions to support life in the ancient past, billions of years ago (Rummel et al. 2014, Grant et al. 2018).
Their 2014 cite isn’t a Mars sample return study, so isn’t about backwards contamination and says explicitly they didn’t study capabilities for extant martian life.
Special Regions are regions ‘‘within which terrestrial organisms are likely to replicate’’ as well as ‘‘any region which is interpreted to have a high potential for the existence of extant martian life.’’
…
At present there are no Special Regions defined by the existence of extant martian life, and this study concentrates only on the first aspect of the definition.
That matters because there are ideas for ways that non terrestrial life could survive in conditions that are too cold for terrestrial life.·
I cover this in my original preprint in the section
- How Martian life could make perchlorate brines habitable when they only have enough water activity for life at -70 °C – biofilms retaining water at higher temperatures - chaotropic agents permitting normal life processes at lower temperatures – and novel biochemistry for ultra low temperatures
Draft EIS says MISTAKENLY that the 2014 cite represents a consensus opinion within the astrobiology scientific community
Skip to next section– it was not a consensus even for forwards contamination as it was overturned by a 2015 review commissioned by ESA and NASA which emphasized potential for microhabitats within apparently uninhabitable regions, and transport of life on dust
This is what they say in the DRAFT Environmental Impact Statement again: S-4
Consensus opinion within the astrobiology scientific community supports a conclusion that the Martian surface is too inhospitable for life to survive there today, particularly at the location and shallow depth (6.4 centimeters [2.5 inches]) being sampled by the Perseverance rover in Jezero Crater, which was chosen as the sampling area because it could have had the right conditions to support life in the ancient past, billions of years ago (Rummel et al. 2014, Grant et al. 2018).
This is where you need a bit of background knowledge to see the mistake. Their source is is NOT a consensus position. Even as that 2014 report by Rummel et al was in publication, NASA and ESA commissioned a review which overturned many of its findings.
It is a serious omission to not mention the 2015 study, Review of the MEPAG report on Mars special regions which reversed or corrected many of its findings.
Review of the MEPAG report says maps made from orbit only provide information at the scale of the map - and “can only represent the current (and incomplete) state of knowledge for a specific time”
Skip to next sectionThe biggest change was on the utility of maps to map out the special regions. The review board said that maps made from orbit can only provide information at the scale of the map and so are a generalization. They say that maps can only represent the current (and incomplete) state of knowledge for a specific time.
Jezero crater now has no sign of life from orbit - BUT
...
Could there be life using biofilms to make it habitable in the dirt, salts or under rocks?
Jezero crater in the past had a lake and delta
2014 study said maps mark out "special regions" where earth microbes might survive.
2015 review said maps only tell us about habitability at the scale of the map and knowledge when the map was made.
Background map: Location Map for Perseverance Rover - NASA
Ancient lake from: Photo tour of Jezero Crater: Here's where Perseverance landed on Mars
They say that this knowledge is subject to change as new information is obtained:
Another potential source of misinterpretation related to the use of maps in Special Region studies is the issue of scale. Identification of a Special Region needs a multiscale approach (see also the discussion in Chapter 2, “Detectability of Potential Small Scale Microbial Habitats,” and thus, as far as missions to Mars are concerned, conservatism demands that each landing ellipse be scrutinized on a case-by-case basis.
Maps, which come necessarily at a fixed scale, can only provide information at that scale and are, therefore, generalizations
…
In general, the review committee contends that the use of maps to delineate regions with a lower or higher probability to host Special Regions is most useful if the maps are accompanied by cautionary remarks on their limitations. Maps that illustrate the distribution of specific relevant landforms or other surface features can only represent the current (and incomplete) state of knowledge for a specific time—knowledge that will certainly be subject to change or be updated as new information is obtained.
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In more detail, the temperature and humidity is only measured on large scales, and microhabitas can be substantially different physically and chemically.
The definition of Mars Special Regions is based on temperature and humidity conditions that are measured on spatial scales that do not reflect these conditions within microscale niches that can be potential habitats for microbial communities. Physical and chemical conditions in microenvironments can be substantially different from those of larger scales. Although the SR-SAG2 report considered the microenvironment (Finding 3-10), the implications of the lack of knowledge about microscale conditions was only briefly considered.
There are many examples of these small-scale and microscale environments with microbial communities on Earth. The biofilm, a mix of many species of microbes, can make the conditions suitable for microbial propagation despite adverse and extreme surrounding conditions.
There are many examples of small-scale and microscale environments on Earth (see e.g., Lindsay and Brasier 2006) that can host microbial communities, including biofilms, which may only be a few cell layers thick. The biofilm mode of growth, as noted previously, can provide affordable conditions for microbial propagation despite adverse and extreme conditions in the surroundings.
This is something that has become more obvious on Earth in recent years. We need a better understanding of this for Mars.
On Earth, the heterogeneity of microbial colonization in extreme environments has become more obvious in recent years (e.g., Azúa-Bustos et al. 2015). To identify Special Regions across the full range of spatial scales relevant to microorganisms, a better understanding of the temperature and water activity of potential microenvironments on Mars is necessary.
They give examples of microenvironments - craters, and even microenvironments underneath rocks could become special regions when the temperature and humidity on the larger landscape-scale doesn’t permit terrestrial life to flourish on Mars.
For instance, the interior of the crater Lyot in the northern mid-latitude has been described as an optimal microenvironment with pressure and temperature conditions that could lead to the formation of liquid water solutions during periods of high obliquity (Dickson and Head 2009). Craters, and even microenvironments underneath and on the underside of rocks, could potentially provide favorable conditions for the establishment of life on Mars, potentially leading to the recognition of Special Regions where landscape-scale temperature and humidity conditions would not enable it.
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2015 Review of the 2014 MEPAG report has a long section about how biofilms with many microbes working together can make microhabitats in regions that are otherwise inhospitable for life - Nilton Renno has suggested the Curiosity brines could be inhabitable in this way
Skip to next sectionThe 2015 review also has a long section about biofilms and the ability of microbes to modify microhabitats by surrounding themselves with “extrapolymeric substances” - proteins, polysaccharides, lipids, DNA and other molecules.
These EPS can modify the microhabitat and make it much more habitable for microbes and help them cope with stressors in the environment.
How EPS (extrapolymeric substances) can make a “home” of the hostile Martian surface.
Some of the environment stressors
100% humidity varies to 0%
Heat, cold, UV, dust storms
Oxidants, nutrients
Algae may add oxygen
Retains moisture from night to daytime when temperature soars from -70°C to above 0°C.
Cryoprotectants - protects from cold shock
Extrapolymeric substances (EPS): proteins, DNA, lipids, polysaccharides, other large organic moleculese.
A biofilm is like a microbe’s “house” which can keep it warm, wet, protected from UV and which it shares with other mirobes.
My use of the word "house" in that graphic as a metaphor for what biofilms do comes from this paper:
If biofilms can be metaphorically called a “city of microbes” (24), the EPS represent the “house of the biofilm cells.” The EPS determine the immediate conditions of life of biofilm cells living in this microenvironment by affecting porosity, density, water content, charge, sorption properties, hydrophobicity, and mechanical stability (6).
While reading this we need to bear in mind also that this is a study of forward contamination, and they don’t consider native Martian life which might be pre-adapted to withstand stressors terrestrial microbes can’t and might have a different biochemistry from terrestrial microbes.
They first observe that microorganisms typically live and proliferate in communities [of many different species] rather than single cells or unispecies populations
In nature, microorganisms typically live and proliferate as members of communities rather than as single cells or populations.
Biofilms are very common where the many species of microbes surround themselves with a self-produced matrix of various macromolecules such as proteins, polysaccharides, lipds and DNA, the EPS (Extrapolymeric substances). These protect them from stresses like dessication, radiation, harmful chemical agents and predators.
A widespread growth form of life in natural habitats occurs as multispecies biofilms where the cells are embedded in a self-produced extracellular matrix consisting of polysaccharides and proteins, which includes other macromolecules such as lipids and DNA. These so-called extrapolymeric substances (EPS) provide protection against different environmental stressors (e.g., desiccation, radiation, harmful chemical agents, and predators). Biofilms are highly organized structures that enable microbial communication via signaling molecules, disperse cells and EPS, distribute nutrients and release metabolites, and facilitate horizontal gene transfer.
The majority of known microbial communities on Earth are able to do this.
The majority of known microbial communities on Earth are able to produce EPS, and the protection provided by this matrix enlarges their physical and chemical limits for metabolic processes and replication.
These EPS also make the microbial commuities more tolerant to multiple simultaneous stressors (ex. on Mars there’s the UV, dessication, ionizing radiation, extreme cold, the high salt concentrations, perchlorates, hydrogen peroxide amongst other stressors, but a biofilm could protect the community from all of those).
EPS also enhances their tolerance to simultaneously occurring multiple stressors and enables the occupation of otherwise uninhabitable ecological niches in the microscale and macroscale. The presence of EPS within a microbial community has implications for several aspects of the SR-SAG2 report, including the physical and chemical limits for life, the dimension of habitable niches versus the actual resolution capability of today’s instruments in Mars orbit, colonization of brines, and tolerance to multiple stressors.
The EPS are also excellent for protection against extreme cold (cryoprotectant).
In extreme cold and salty habitats (e.g., brines of sea ice and cryopegs in permafrost), EPS has been found to be an excellent cryoprotectant (Goordial et al. 2013). For instance, production of EPS by the marine psychrophilic bacterium Colwellia psychrerythraea increases in response to low temperatures, to high pressure, and to salinity (Marx et al. 2009). Another example is the EPS produced by hypolithic microbial communities that develop on the undersides of translucent rocks in the Dry Valleys of Antarctica, which is thought to facilitate the water-holding capacity of cells and promote microbial survival, growth, and succession (Makhalanyane et al. 2013; de los Ríos et al. 2014).
The production of EPS lets microbial communities survive in nearly any undisturbed environment with enough water and nutrients.
The production of EPS enhances the resistance of cells to a wide variety of environmental stresses, when compared to their resistance in planktonic growth mode, and enables microbial communities to thrive in nearly any undisturbed environment that receives sufficient water and nutrients.
Microbial stowaways to Mars would likely need to develop biofilms to establish themselves on Mars.
Given the wide distribution and advantages that communities of organisms have when they live as biofilms enmeshed in copious amounts of EPS, it is likely that any microbial stowaways that could survive the trip to Mars would need to develop biofilms to be able to establish themselves in clement microenvironments in Special Regions so that they could grow and replicate.
So when asking if spacecraft could be sources of forward contamination on Mars a central question is whether the spacecraft has enough terrestrial life on it to be able to establish a biofilm on Mars. It’s not about the species only but about how many microbes there are to establish a “beachhead” on the martian surface for terrestrial life to start growing there.
They say the experiments hadn’t yet been done to establish this.
This consideration raises a fundamental question about the probability of a successful colonization by microbial contaminants from Earth in martian habitats, one recently formulated in an essay by Siefert et al. (2012). Studies have been conducted to determine the bioburden found on spacecraft and their assembly facilities (e.g., Satomi et al. 2006; Rettberg et al. 2006; Moissl-Eichinger et al. 2012, 2015). But, to date, there have been no experimental attempts to determine whether the number and type of cells that remain on spacecraft after sterilization and/or after launch and travel through space (e.g., even in low Earth orbit) are sufficient to establish a population and/or community of microorganisms within a Mars Special Region.
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That last paragraph is quite encouraging that our spacecraft may well not have sent enough life to Mars for it to start to colonise the surface.
However, the brines Curiosity found in Gale Craters (which they didn’t know about at the time) would seem to fit their description of conditions that could be made habitable by a biofilm of terrestrial life.
Nilton Renno, amongst other things was part of the team that found evidence of liquid water for the Phoenix lander project, and the droplets on the Phenix lander legs, who runs the REMs weather station on Curiosity, and who has written a big review of the possibilities for liquid water on Mars.
, faculty bio at the University of Michigan.
He has suggested the very cold brines found by Curiosity in Gale crater (and probably also present in Jezero crater) could be habitable to a biofilm that can regulate its microhabitat in this way, for instance, retain the water through to warmer conditions in daytime
"Life as we know it needs liquid water to survive. While the new study interprets Curiosity's results to show that microorganisms from Earth would not be able to survive and replicate in the subsurface of Mars, Rennó sees the findings as inconclusive. He points to biofilms—colonies of tiny organisms that can make their own microenvironment."
, “Mars liquid water: Curiosity confirms favorable conditions”,
As an example, a biofilm could retain the liquid water from the night when it is too cold for life but has enough water activity for life, through to the day time when the temperatures can reach above 0 °C close to the surface where these brines form.
Throughout environmental changes, biofilm can act as a “protective clothing” to provide a suitable habitat for their survival and metabolism. In the extreme temperature environment, the biofilm serves more as a “smart garment” when dealing with such high temperatures: it can resist the external high temperature and render the interior suitable for growth and reproduction. On the other hand, biofilm can also stabilize the internal environment when it is extremely cold outside, causing no freeze of the cells and enabling them to survive.
…
In extreme environments, microorganisms regulate the expression of a series of biofilm-forming genes through QS, nucleotide second messenger-based signaling, etc., to endow microorganisms with the capability of becoming resistant to various extreme environments such as UV radiation, extreme temperature and pH, high salinity, high pressure, poor nutrients, antibiotics, etc.
. Biofilms: The Microbial “Protective Clothing” in Extreme Environments
I am not sure what this means by “stabilize the internal environment”. But biofilms would also modify the thermal inertia of the soil. Could this reduce the day - night variation in temperature?
Soil moisture does reduce variability in semi-arid regions by evaporation feedbacks, and by thermal inertia.
. Role of soil thermal inertia in surface temperature and soil moisture‐temperature feedback.
Anyone reading this know?
Idea of larger propagules of a cluster of cells - and my own suggesetion of a half mm diameter propagule evolved to be easily transported in dust storms by repeated bounces (saltation) which can move a particle of this size hundreds of kilometers a day during dust storms
Skip to next sectionAlso they don’t mention it here, but do elsewhere, a propagule transported in the duststorms could be a a cluster of cells.
12)
Atmospheric transport can move microbial cells and spores over long distances, as is known from investigations of foreign microbes delivered to North America from Africa via Saharan dust (Chuvochina et al. 2011; Barberàn et al. 2014) and Asia (Smith et al. 2012).
…
In addition to dilution effects, the flux of ultraviolet radiation within the martian atmosphere would be deleterious to most airborne microbes and spores.
However, dust could attenuate this radiation and enhance microbial viability.
In addition, for microbes growing not as single cells but as tetrades or larger cell chains, clusters, or aggregates, the inner cells are protected against ultraviolet radiation. Examples are methanogenic archaea like Methanosarcina, halophilic archaea like Halococcus, or cyanobacteria like Gloeocapsa. This is certainly something that could be studied and confirmed or rejected in terrestrial Mars simulation chambers where such transport processes for microbes (e.g., by dust storms) are investigated. The SR-SAG2 report does not adequately discuss the transport of material in the martian atmosphere.
In my preprint I explored the idea of propagules as large as half a mm across which could be transported via repeated bounces (saltation). That half mm diameter propagule could be a community of cells along with the extracellular matrix so that the biofilm doesn’t need to be restarted completely from scratch in a new location.
Bouncing dust grains or propagules would travel 250 to 850 kilometers per day in a dust storm (at typical saltation speed of 3 to 10 meters per sec).
Dust grains on Mars of 500 microns diameter can bounce up to several meters with each bounce with a height of tens of cms. A biofilm propagule this size covered in iron oxide microparticles for protection from UV could contain over 24 million microbes at 1 micron diameter.
Artist’s impression of a typical bounce based on figure 2b from . Giant saltation on Marssuperimposed on photograph of the top of a large sand dune taken by Curiosity on December 23, 2015 , NASA Rover's Sand-Dune Studies Yield Surprise
I cover this in my original preprint in the sections:
- Could Martian life be transported in dust storms or dust devils, and if so, could any of it still be viable when it reaches Perseverance?
- Native Martian propagules of up to half a millimeter in diameter (including spore aggregates and hyphal fragments) could travel long distances with repeated bounces (saltation) - if they can withstand the impacts of the bounces
- Martian propagules could evolve extra protection such as a shell of agglutinated iron oxide particles to protect themselves from UV
- Martian life could also use iron oxides from the dust for protection from the impact stresses of the saltation bounces - or it might use chitin - a biomaterial which is extremely hard and also elastic and is found in terrestrial fungi and lichens
Then as a source for these propagules:
- Potential for spores and other propagules transferred from distant regions of Mars similarly to transfer of spores from the Gobi desert to Japan – if little dust from a nearby habitat with of order 1000 viable spores per gram is blown to Perseverance’s site during a dust storm, this could still return several cells per gram
Proposed surface microhabitats on Mars outside Jezero crater – droplets on the legs of the Phoenix lander, brines that form rapidly when salt overlays ice at high latitudes, caves that vent to the surface, fumaroles, and fresh water melting around heated grains of dust trapped in polar ice layers through the solid state greenhouse effect – these could achieve higher densities of life and be a source for propagules in the dust
Many other changes in the 2015 review in the direction of increasing the potential for habitability of Mars for terrestrial life
Skip to next sectionHere are some of the other changes the 2015 study made relevant to the detection of life:
Terrestrial life that depends on other life could find a home on Mars, not just life that is able to produce all its own organics, because of the organics present on Mars:
Finding 2-1: Modern Mars environments may contain molecular fuels and oxidants that are known to support metabolism and cell division of chemolithoautotrophic microbes on Earth.
Revised Finding 2-1: Modern Mars environments may contain chemical compounds that are used as electron donors and electron acceptors by chemolithoautotrophic microbes. If organic compounds are also present on Mars, then heterotrophic microbes may also find a home there.
The methane on Mars could be produced by processes that involve liquid water and source regions for methane should be considered as uncertain regions for terrestrial life to inhabit.
Finding 2-4: Organic compounds are present on Mars (or in the martian subsurface); although in very low concentrations in samples studied to date. Such detections are not used to distinguish Special Regions on Mars.
Revised Finding 2-4: Organic compounds are present on Mars (or in the martian subsurface); although in very low concentrations in samples studied to date. Abiotic or potentially biotic processes can explain the detection of episodic plumes of methane at various latitudes. In both cases, liquid water solutions would be involved. Therefore, the source regions of methane are considered as Uncertain Regions, even if the methane production is abiotic.
In this next quote the RSLs are Recurrent Slope Lineae - streaks that form in spring, grow and expand through the summer and fade away later in the year on steep sun facing slopes on Mars. These can be found anywhere on Mars including where Curiosity was and potentially could be in Jezero crater.
They were originally thought to be due to liquid water. Then evidence turned up suggesting that they are due to dust / dirt flowing down the slopes, but then problems turned up with the “dry granular flow” models and they don’t seem to explain everything. The 2015 study said that water could still be involved.
There are some problems with the dry granular flow models for RSLs, so processes involving liquid water can’t be definitively excluded.
Finding 4-8: The 2006 Special Regions analysis did not consider dark/light slope streaks to be definitive evidence for water. Recent results have strengthened that conclusion for non-RSL slope streaks.
Revised Finding 4-8: The 2006 Special Regions analysis did not consider dark/light slope streaks to be definitive evidence for liquid (saline) water. Although some recent results have strengthened that conclusion for non-RSL slope streaks, other recent reports suggest that there are problems explaining all dark slope streaks by dry granular flow, and therefore aqueous processes cannot be definitely excluded for all dark slope streaks.
This is about distant habitats on Mars, not directly relevant but it could be a source for life in dust storms. The polar dark streaks are streaks that form in the debris of CO2 geysers especially in Richardson crater in the southern hemisphere. The revised report says that they could involve liquid water through a solid-state greenhouse effect while the 2014 report said they most likely don’t involve liquid water at all.
Finding 4-9: Polar dark dune streaks are considered extremely unlikely to involve liquid water warmer than 253 K (–20°C), and most likely do not involve liquid water at all, given the low surface temperatures present when they are active.
Revised Finding 4-9: A conservative interpretation of the evidence suggests that polar dark dune streaks could potentially involve liquid brines but only in the presence of heating mechanisms such as solid-state greenhouse effects.
The revised report says there could be buried ice less than 1 meter below the surface in pole facing slopes in the tropics and mid latitudes and a detailed analysis is needed to see if there is ice at a particular site.
Finding 5-3: Depths to buried ice deposits in the tropics and mid-latitudes are considered to be >5 m.
Revised Finding 5-3: In general, depths to buried ice deposits in the tropics are considered to be >5 m. However, there is evidence that water ice is present at depths of <1 m on pole-facing slopes in the tropics and mid latitudes. Thus, a local detailed analysis for a particular area is necessary to determine if it could be a Special Region.
Detailed analysis is needed to see if the mid-latitude mantle is desiccated or may have transient liquid water.
Finding 5-4: The mid-latitude mantle is thought to be desiccated, with low potential for the possibility of modern transient liquid water.
Revised Finding 5-4: The mid-latitude mantle is thought to be desiccated, with low potential for the possibility of modern transient liquid aqueous solutions. However, a local detailed analysis for a particular area is necessary to determine if it could be a Special Region.
It’s not actually certain that terrestrial life has a limit of -18 C for cell division. There’s possibility that cells can divide well below that temperature but very slowly, on timescales too slow to detect in most experiments done in the laboratory.
“Finding 3-1: Cell division by Earth microbes has not been reported below –18°C (255K).
“Revised Finding 3-1: Cell division by Earth microbes has not been reported below –18°C (255K). The very low rate of metabolic reactions at low temperature result in doubling times ranging from several months to year(s). Current experiments have not been conducted on sufficiently long timescales to study extremely slow-growing microorganisms.”
, Appendix B: MEPAG SR-SAG2 Findings, Revisions, and Updates
2015 review of the 2014 MEPAG report recommends further research into transport of terrestrial life in the dust storms and detectability of potential small-scale microbial habitats on Mars as knowledge gaps to be looked at in the future
Skip to next sectionThis is in their Appendix A.
The need for more research into detectability of potential small-scale microbial habitats
Detectability of Potential Small-Scale Microbial Habitats
Perform in situ investigations in extreme environments on Earth to deepen our knowledge about microbial processes and habitability at micron scales. Adapt and optimize existing technologies and develop new ones to undertake the kind of investigations which may be used in the future exploratory missions to other planets and moons of astrobiological relevance.
Need for more research into microbial viability of terrestrial life when transported in dust storms
Translocation of Terrestrial Contamination
Undertake investigations of transport mechanisms and microbial viability in Mars simulation chambers—e.g., the Mars Surface Wind Tunnel facility at NASA’s Ames Research Center or the low-pressure recirculating wind tunnels in the Mars Simulation Laboratory at Aarhus University—wherein microbes and spores are exposed to Mars-relevant levels of ultraviolet radiation, desiccation, nutrient deficit, and air movement, to assess the likelihood of survival during transport by, for example, dust storms.
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As far as I can tell this research hasn’t been done, at least I find no recent studies that cite the older studies on the topic.
In more detail on dust the 2015 report says dust can block UV and make microbes more viable, and microbes often occur in cell clusters and the inner cells would be protected against UV in dust storms
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Atmospheric transport can move microbial cells and spores over long distances, as is known from investigations of foreign microbes delivered to North America from Africa via Saharan dust (Chuvochina et al. 2011; Barberàn et al. 2014) and Asia (Smith et al. 2012).
…
In addition to dilution effects, the flux of ultraviolet radiation within the martian atmosphere would be deleterious to most airborne microbes and spores.
However, dust could attenuate this radiation and enhance microbial viability. In addition, for microbes growing not as single cells but as tetrades or larger cell chains, clusters, or aggregates, the inner cells are protected against ultraviolet radiation. Examples are methanogenic archaea like Methanosarcina, halophilic archaea like Halococcus, or cyanobacteria like Gloeocapsa. This is certainly something that could be studied and confirmed or rejected in terrestrial Mars simulation chambers where such transport processes for microbes (e.g., by dust storms) are investigated. The SR-SAG2 report does not adequately discuss the transport of material in the martian atmosphere.
Also this is all about forwards contamination by terrestrial life. What about Martian life adapted to the dust storms over billions of years? Could it develop adaptations to survive transport in dust storms that terrestrial life doesn’t have? I suggest native Martian life could propagate via much larger grains up to half a millimeter in diameter if it can survive the impact shocks of repeated bounces across the Martian landscape.
I cover this in my original preprint in the sections:
- Native Martian propagules of up to half a millimeter in diameter (including spore aggregates and hyphal fragments) could travel long distances with repeated bounces (saltation) - if they can withstand the impacts of the bounces
- Martian spores could evolve extra protection such as a shell of agglutinated iron oxide particles to protect themselves from UV
- Martian life could also use iron oxides from the dust for protection from the impact stresses of the saltation bounces - or it might use chitin - a biomaterial which is extremely hard and also elastic and is found in terrestrial fungi and lichens
The Grant et al cite isn’t about planetary protection
Skip to next sectionTheir second cite (Grant et al. 2018) seems to be just to support the sentence
which was chosen as the sampling area because it could have had the right conditions to support life in the ancient past, billions of years ago
It has a section about Jezero crater and about how the teams selected it as an ancient delta with a high potential for preserving past life. It doesn’t have anything about whether there is present day life there except to say it’s not a “special region” where terrestrial life could propagate in the forwards direction. It refers to another paper for the detailed assessment
Moreover, planetary protection considerations warrant the exclusion of “special regions” where liquid water may exist at the surface (e.g., recurring slope lineae (RSL) (McEwen et al., 2014)), where there is evidence for water or ice within 1 m of the surface (Rummel et al., 2014; Golombek et al., 2015), or possibly other induced special region. (e.g., Shotwell et al., 2017).
. The science process for selecting the landing site for the 2020 Mars rover.
The paper continues by saying it’s not a paper about planetary protection:
These atmospheric and planetary protection assessments are described in separate publications (e.g., Shotwell et al., 2017), whereas this manuscript focuses mostly on the terrain.
. The science process for selecting the landing site for the 2020 Mars rover.
And Shotwell at al is on “The potential for the off-nominal landing of an RTG-1491 powered spacecraft on Mars to induce and [sic] artificial special region”
However Gale crater is an excellent example to show that this method of modelling and trying to assess habitability from orbit has limitations. AFTER Curiosity landed, orbital missions spotted one of the RSL’s only a few kilometres from Curiosity’s route. It was close enough for Curiosity to reach, but Curiosity is not sufficiently sterilized to study them close up, leading to debates about how close is safe to go
See: JPL, 2016, NASA Weighs Use of Rover to Image Potential Mars Water Sites,
Draft EIS says (MISTAKENLY) potential environmental impacts would not be significant
Skip to next section– 2009 NRC study says risk of large scale effects appears to be low but not demonstrably zero, and they can’t rule out the possibility of large scale effects on the Earth’s biosphere from martian life in the distant past
This is what they say in the DRAFT Environmental Impact Statement: 3-16
The relatively low probability of an inadvertent reentry combined with the assessment that samples are unlikely to pose a risk of significant ecological impact or other significant harmful effects support the judgement that the potential environmental impacts would not be significant.
They don’t cite this to any source and presumably base it on their own remarks in the rest of their report about how unlikely they think it is that there is life on Mars.
But that’s not what their own source says, the NRC study from 2009 is clear on the matter:
"The committee found that the potential for large-scale negative effects on Earth’s inhabitants or environments by a returned martian life form appears to be low, but is not demonstrably zero"
The committee looked at the same meteorite argument this EIS looked at and said it’s simply not possible to rule out large scale effects from introduced Martian life in the past
"As noted above, it is also possible that if life had an independent origin on Mars, living martian organisms might have been delivered to Earth. Although such exchanges are less common today, they would have been particularly common during the early history of the solar system when impact rates were much higher.
Despite suggestions to the contrary, it is simply not possible, on the basis of current knowledge, to determine whether viable Martian life forms have already been delivered to Earth. Certainly in the modern era, there is no evidence for large-scale or other negative effects that are attributable to the frequent deliveries to Earth of essentially unaltered Martian rocks. However the possibility that such effects occurred in the distant past cannot be discounted.
Thus it is not appropriate to argue that the existence of martian meteorites on Earth negate the need to treat as potentially hazardous any samples returned from Mars by robotic spacecraft.
A prudent planetary protection policy must assume a biological hazard exists from Mars sample return and that every precaution should be taken to ensure the complete isolation of any deliberately returned samples, until it can be determined that no hazard exists.”
They don’t give any examples there but the Great Oxygenation Event is a natural one to consider. This happened only half a billion years ago. Before then for billions of years Earth had almost no oxygen.
We don’t know where photosynthetic life originated. It might well have evolved on Earth. But we can’t be sure it didn’t come from Mars which might have had it first. If so this would be a major change to Earth’s atmosphere and seas, and we can’t discount the possibility completely that it was caused by martian life.
It might or might not have been a mass extinction event depending on what ones views are about the rather limited evidence about chains of large anaerobic cells that predated the great oxidation event.
I cover this in my preprint about the draft EIS under
- The Great Oxygenation Event which transformed Earth’s atmosphere and oceans chemically gives a practical example of a way life from another Mars-like planet could in principle cause large scale changes to an Earth-like planet
Example of a mirror-life blue-green algae - chemistry reflected in a mirror - likely to be able to metabolize both forms of life but only produce mirror organics
Skip to next sectionLet's take the example of mirror life blue-green algae. This is identical to terrestrial life but with all the chemistry reflected as in a mirror, DNA and RNA spiral the opposite direction and so on. Of all the alternative biochemistries this is the one with most agreement on. All the astrobiologists agree that mirror life would just work.
There are varying views about why we have ordinary rather than mirror life. Some think that there are reasons why normal rather than mirror life is favoured. But other experts say it is just the luck of the draw and could have gone either way.
Suppose Mars has mirror life and for whatever reason it hasn’t been able to get here on a meteorite. This could cause similar large scale changes to Earth’s environment.
Normal life, Mirror life, DNA, amino acids, sugars, fats, everything flipped. Most normal life can’t eat mirror organics. Martian mirror life might be able to eat normal organics. Background image from NOAA, DNA spiral from Pusey et al, 2012, cites in preprint
We don’t know why terrestrial life all has DNA spiralling the same way and most organics in only one form and not its mirror. It may just be chance and if so Martian life could have life with the DNA spiralling the opposite way - or both forms of life.
The Martian surface conditions would rapidly destroy organics from life over timescales of millions of years and most of the organics are likely to be from infall from space, in form of comets, asteroids, interplanetary dust and so on. So the organics are likely to occur in both forms, ordinary and mirror.
Some terrestrial microbes have the capability to metabolize mirror life but this very rare and no higher lifeforms can do this.
Life from Mars, whether the same symmetry as terrestrial life or mirror life, is likely to be able to metabolize both forms of organics as that would double the amount of organic material it can consume.
Not saying this is a likely scenario. But it can’t be ruled out. This is new to my original preprint as far as I know but it should survive peer review.
It combines together
- Universal agreement that a cell with everything in its mirror form would still function.
- Research into attempts to convert terrestrial life to mirror life by gradually flipping components of a cell into a mirror one by one
- Research into biosafety levels needed for mirror life - they will make it safe by making it dependent on chemicals only available in the laboratory
- Detailed scenarios of what could happen if mirror life escaped on Earth without those precautions and if it had or acquired the ability to metabolize non mirror organics - it would gradually change all organics to mirror organics
- Astrobiologists say we shouldn’t assume Martian life is based on terrestrial biochemistry when we search for it
- Some experts are of the view that the choice between life and mirror life was just a matter of chance, making it 50–50 that any independently originated Martian life is mirror life.
Based on all that, there has to be a possibility though likely very small that Mars could have mirror life and that the mirror life has never got to Earth.
I cover this in my preprint about the draft EIS under
- If Mars has mirror life, returning it could potentially cause a similar large scale transformation of terrestrial ecosystems by gradually converting organics to mirror organics – an example worst case scenario
My clearest example here is chroococcidiopsis but flipped as in a mirror, DNA spirals the other way and all the organics are mirrored. Some terrestrial microbe can use mirror organics but no known multicellular life can subsist on mirror organics.
If Mars has mirror life, it’s bound to develop the isomers that let it digest ordinary organics too because of the constant rain of organics from comets, asteroids and interplanetary dust.
Return that to Earth and it will gradually turn all the organics throughout all the ecosystems it inhabits into indigestible mirror organics.
Chroococcidioopsis survives on rock + nitrogen + water + sunlight
Mirror chroococcidiopsis could spread on Earth without any support from other life.
Photograph shows chroococcidiopsis in a cave at Ares Station, Cantabria in the Iberian peninsula – with a transparent covering of other microbes – it can live on its own or in colonies with other life and it can also live inside rocks. Photo by Proyecto Agua on Flickr
Humans would survive, and the process would likely take centuries, but we’d not be able to stop it and eventually would need to protect all our ecosystems in greenhouses and similar undersea habitats with the mirror life kept out as far as possible as well as mirror organics.
In this article we wouldn’t actually all die because of that. After all we have figured out how to live in space even though nobody has built a space colony yet. For sure we can live in habitats on a world with mirror life indigenous outside our habitats.
. Mirror-image cells could transform science-or kill us all.
Example worst case scenarios for ecosystems, mirror life nanobes - similar in size to a SARS-COV2 virus - as for the shadow biosphere hypothesis
Skip to next sectionThen it could be RNA life, which could permit very small nanobes similar in size to the SARS CoV2 virus which causes COVID or smaller. Indeed we have DNA based ultramicrobacteria which can pass through 0.1 micron filters, only double the diameter of the SARS - CoV2 virus. There was a lot of interest at one point in a shadow biosphere of RNA nanobes that could co-exist with terrestrial life.
. The Quest for a Universal Theory of Life: Searching for Life as we don't know it , pp 213 - 214
It would have some advantages, protean grazing would ignore it as too small, and the high surface to volume ratio is an advantage in nutrient poor environments.
. Nano-sized and filterable bacteria and archaea: biodiversity and function. See section: Selective Pressures for Small Size
We never found that shadow biosphere. But early terrestrial life has to have been much simpler than DNA. Probably we did have early much simpler forms of life that could survive as much smaller nanobes than for terrestrial life, but terrestrial life made it extinct.
However we can't guarantee that terrestrial life would out compete mirror nanobes from Mars, after all it was a viable hypothesis for a shadow biosphere for Earth.
Potential for large scale effects should be re-assessed based on many new potential microhabitats on Mars both for Jezero crater and elsewhere on Mars
Skip to next section- not known at the time of the 2009 report
The 2009 report is way out of date now due to many new discoveries since then.
I cover some of these stories in the media in my astrobiology wiki:
The 2009 report was written before
- Direct observation of what appear to be water droplets on the legs of the Phoenix lander
- Liquid Water from Ice and Salt on Mars - Discovery that water droplets like the ones seen on the Phoenix lander leg form rapidly whenever salt overlays ice on Mars. As Nilton Renno put it:
"This is a small amount of liquid water. But for a bacteria, that would be a huge swimming pool - a little droplet of water is a huge amount of water for a bacteria. So, a small amount of water is enough for you to be able to create conditions for Mars to be habitable today'. And we believe this is possible in the shallow subsurface, and even the surface of the Mars polar region for a few hours per day during the spring."
- Discovery of the Recurring Slope Lineae which grow through the summer and spread out and fade as the year closes – they are now thought to be partly caused by dust cascades but this doesn’t explain everything and they are likely to be a mix of the dry and wet formation models 2 - Unraveling the Mysteries of Recurring Slope Lineae
- Detection of a possible RSL in Gale Crater
- NASA Weighs Use of Rover to Image Potential Mars Water Sites - Curiosity’s discovery of brines in Gale crater that form briefly in the early morning and late evening as a result of the salts taking up water from the atmosphere – with enough water activity for life, though too cold for terrestrial life
. Water and brines on Mars: current evidence and implications for MSL - . Nilton Renno has suggested this could be habitable to a biofilm that can regulate its microhabitat, for instance, retain the water through to warmer conditions in daytime Mars liquid water: Curiosity confirms favorable conditions”
- Discovery of a seasonal excess of oxygen in spring / summer and deficit in winter atmosphere 2019, With Mars methane mystery unsolved, Curiosity serves scientists a new one: Oxygen
. Seasonal variations in atmospheric composition as measured in Gale Crater - Modelling shows some of the Martian brines could be oxygen rich, taking up oxygen from the atmosphere in the very cold conditions on Mars, permitting aerobes or even primitive sponges or other forms of multicellularity - Stamenković‘s oxygen-rich briny seeps model
- see Vlada Stamenkovic. "Origins of Life & Habitability - authors website with bibliography - and author shared link to the article"s
I did an email interview with the author for Wikinews, and did a longer version in my astrobiology wiki: Sponges on Mars? We ask Stamenković about their oxygen-rich briny seeps model - Discovery of a seasonal methane cycle and methane spikes
. Methane on Mars and habitability: challenges and responses.
. Seasonality in Mars atmospheric methane driven by microseepage, barometric pumping, and adsorption - Some evidence that life may be able to survive on Mars using just the night time humidity - by growing some lichens, cyanobacteria, a black yeast and microcolonial fungi directly in Mars simulation conditions without liquid water forming.
. Adaptation of an Antarctic lichen to Martian niche conditions can occur within 34 days.
. Protein patterns of black fungi under simulated Mars-like conditions - Discovery that terrestrial microbes can use micropores in salt deposits as a source of humidity when the air is otherwise too dry for them
. Microbial colonization of halite from the hyper-arid Atacama Desert studied by Raman spectroscopy
Cassie Conley and, separately, Paul Davies have suggested these micropores as potential habitats on present day Mars
, Going to Mars Could Mess Up the Hunt for Alien Life
, The key to life on Mars may well be found in Chile
Salt deposits however may be rare in Jezero crater. The deposits of most interest to astrobiology in Jezero crater consist mainly of clays and carbonates, and it doesn’t have the large bright salt deposits of Mount Sharp (Lerner, 2019). - Discovery through radar imaging of large lakes of liquid water deep below the polar ice (though there is likely no communication with the surface)
. Liquid water found beneath the surface of Mars
. Radar evidence of subglacial liquid water on Mars
These discoveries have lead to many proposed microhabitats on Mars that weren’t known at the time of the 2009 or 2012 studies. The potential for large scale changes in Earth’s environment from a sample return needs to be re-assessed based on an increased potential for returning Martian life.
Some of these are discoveries or suggestions for potential habitats in Jezero crater itself.
These discoveries have lead to many proposed microhabitats on Mars that weren’t known at the time of the 2009 or 2012 studies. The potential for large scale changes in Earth’s environment from a sample return needs to be re-assessed based on an increased potential for returning Martian life.
Some of these are discoveries or suggestions for potential habitats in Jezero crater itself.
Also there could be recurring slope lineae in Jezero crater as these can be hard to detect from orbit and one site was found in Gale crater after Curiosity landing.
Also all of these could be habitable elsewhere on Mars if not in Jezero crater, and there are many new discoveries since then that could lead to habitats elsewhere on Mars that could be a source for viable spores or propagules that can reach Jezero crater in the dust storms
I cover this in my original preprint in the section
- Proposed surface microhabitats on Mars outside Jezero crater – droplets on the legs of the Phoenix lander, brines that form rapidly when salt overlays ice at high latitudes, caves that vent to the surface, fumaroles, and fresh water melting around heated grains of dust trapped in polar ice layers through the solid state greenhouse effect – these could achieve higher densities of life and be a source for propagules in the dust
Our understanding of the Martian surface and potential for life has changed so much in the last decade - NASA needs a new study to revisit the question before they can evaluate the potential for returning life from Jezero crater properly
Skip to next sectionWith so many new discoveries in the last 13 years, a cite from 2009 is not likely to give a well-informed view of the potential effects of returning life from Mars in a Mars sample return.
NASA needs a new study to revisit the question now, 13 years later, before they can evaluate what the potential is for returning life in this sample.
Even the more recent 2012 ESF Mars sample return study was written before most of these discoveries, and doesn’t look at this particular topic in depth
We don’t have any comprehensive sample return study that takes account of the new science since the 2009 NRC report.
Draft EIS OMITS the 2012 European Space Foundation study which reduced the size limit to 0.05 microns from the previous value of 0.2 microns
Skip to next section– a serious omission since containment at 0.05 microns is well beyond the capability of BSL-4 facilities
This is rather similar to the way they cited the 2014 report on special regions by Rummel et al and didn’t cite the 2015 review that overturned most of its conclusions.
They cite the 2009 NRC report on a Mars sample return
. Assessment of Planetary Protection Requirements for Mars Sample Return Missions (Report)
That used the limit of 0.2 microns from 1999, but they don't cite the 2012 ESF report on a Mars sample return . Mars Sample Return backward contamination–Strategic advice and requirements which reduced that limit to 0.05 microns. That is a significant reduction.
Size limit 1999 to 2012: 0.2 microns
ESF Size limit (2012): 0.05 microns
The European Space Foundation study in 2012 reduced the limit from 0.2 microns to 0.05 microns after the discovery that these ultramicrobacteria are viable after passing through 0.1 micron nanopores
Next size limits review might reconsider ribocells – theoretical size limit 0.01 microns
Background image: SEM of a bacterium that passed through a 100 nm filter (0.1 microns), larger white bar is 200 nm in length . Passage and community changes of filterable bacteria during microfiltration of a surface water supply
There were two very significant new discoveries that greatly reduced the minimum size limits required for filters to contain Marian biology. First was the discovery of ultramicrobacteria that could pass through 0.1 micron nanopores. This actually goes back to 2005
But this discovery wasn’t considered in the 2009 report.. The other was a discovery that unrelated species of archaea can share capabilities with each other very readily using the very small gene transfer agents (GTAs). They were able to transfer antibiotic resistance to each other overnight in sea water.
. Virus-like particles speed bacterial evolution
. High frequency of horizontal gene transfer in the oceans
That’s why the ESF study
. Mars Sample Return backward contamination–Strategic advice and requirements
reduced the limit from 0.2 microns to 0.05 microns / 0.01 microns in just three years from 2009 to 2012. NASA are presumably still using the old 0.2 microns figure.
The draft EIS is a bit puzzling on this topic. They show no awareness of the ESF recommendation. However they DO try to prevent any particle of 0.05 micron or larger from getting onto the outside of the Earth Return Capsule.
This is what they say in the DRAFT Environmental Impact Statement: 4–7
It is their answer to this question from the general public:
What is the smallest Mars particle that is forbidden to be on the capsule carried to Earth? Dust level, bacteria level, virus level, prion level?
Their reply:
MSR engineering requirements are based on managing unsterilized particles 50 nm in size and larger. MSR selected this size limit because particle size distribution data indicate that the fraction of particles below 50 nm is small (less than 0.06%) and also because the physics of particle transport are such that measures taken to control or exclude particles of 50 nm are also effective for particles of smaller sizes.
A number of studies (National Research Council 1999, Heim et al. 2017) have estimated the minimum sizes for life forms from fundamental inputs such as the genetic material required to permit a cell to perform basic functions [e.g., (Glass et al. 2006)], observations in extreme environments [e.g., (Comoli et al. 2009)] or theoretical constraints that would apply to astrobiology investigations (Lingam 2021). Values from such studies have been used to inform findings on best ractices for sample return missions and MSR has considered those findings in selecting 50 nm for engineering requirements.
The studies they use are very theoretical. They don’t seem to be aware of the studies of ultramicrobacteria passing through 0.1 micron nanopores.
But whatever their reasoning, why would they need to take care not to release 0.05 micron particles to the outside of the capsule, but not need to contain them once the samples get into biosafety laboratories on Earth?
The 2012 European Space Foundation study says its 0.05 micron size limit needs to be reviewed regularly
Skip to next section– this alone is sufficient reason to halt this EIS process until the new size limits review is done
The ESF expected later reductions to happen at a slower pace, but say the size limit will need to be reviewed in the future, after the dramatic reduction from 0.2 microns to 0.05 microns in just 3 years.
Based on our current knowledge and techniques (especially genomics), one can assume that if the expected minimum size for viruses, GTAs or free-living microorganisms decreases in the future, and this is indeed possible, it will be at a slower pace than over the past 15 years
However, no one can disregard the possibility that future discoveries of new agents, entities and mechanisms may shatter our current understanding on minimum size for biological entities. As a consequence, it is recommended that the size requirement as presented above is reviewed and reconsidered on a regular basis.
[bolding as in original cited text]
By 2022, a decade later, another review is certainly required. Also the review board could be expected to revisit the idea of a ribocell, an early form of life without proteins or ribosomes which could in theory be much smaller than a modern cell.
That could lead to an even smaller size limit of 0.01 microns. I’ve added it to the graphic to show how much more of a challenge it would be to contain ribocells if that was the decision:
Size limit 1999 to 2012: 0.2 microns
ESF Size limit (2012): 0.05 microns
The European Space Foundation study in 2012 reduced the limit from 0.2 microns to 0.05 microns after the discovery that these ultramicrobacteria are viable after passing through 0.1 micron nanopores
Next size limits review might reconsider ribocells – theoretical size limit 0.01 microns
I cover this in my preprint about the draft EIS under
- A size limits review board can be expected to consider research into synthetic minimal cells, and protocells – and ideas for simpler RNA world “ribocells” without ribosomes or proteins would be revisited as a result of research since 2012
NASA’s draft EIS has no mention of quarantine or other precautions for accidental release on Earth
Skip to next section– just sterilization of the landing site
Then they just say in the DRAFT Environmental Impact Statement: S-11
Tier II analyses for determination of impacts associated with health and safety would consider the location of the proposed facility and surrounding community/land use type, health and safety system requirements associated with a BSL-4 equivalent facility, and risk analysis involving failure of containment systems that results in a release within the facility.
The draft EIS is inconsistent here. It mentions risk of health to astronauts as a reason not to return the samples to a human run orbiting space station. But it doesn’t talk about the need to quarantine technicians who might come into contact with the samples in the biosafety laboratories.
The only occurrence of the word quarantine is in a reference to the Apollo mission DRAFT Environmental Impact Statement: 3-15
The MSR Campaign is the first sample return mission to be classified as Restricted Earth Return, since the term was defined. (The Apollo 11, 12, and 14 missions were subjected to quarantine upon return until lunar samples were assessed and found to pose no hazard.)
During the Apollo sample returns, there were several times technicians were accidentally exposed to the samples and had to isolate. See page 51 of Lunar Receiving Laboratory Project History
For instance, two technicians had to go into isolation after a leak was found in a sample handling glove for Apollo 11. See page 485 of When Biospheres Collide: A History of NASA's Planetary Protection Programs.
Then 11 technicians had to go into isolation in 1969 when a small cut was found in one of the gloves during preliminary examination of one of the samples returned by Apollo (page 241 of When Biospheres Collide)
The draft EIS doesn’t discuss what happens if technicians are similarly exposed to the sample materials on Earth, even though they raise it as a reason for not returning the samples to an orbital space station.
They describe sterilization of the landing site in some detail.
But having got the sample back to Earth and sterilized the landing site they then just devolve future responsibility to the biosafety laboratory and don’t seem to think any special measures are needed over those used anyway for hazardous materials.
I cover this in my preprint about the draft EIS under
- NASA’s draft EIS has no mention of ANY need for quarantine or other precautions for potential effects on humans or other lifeforms of accidental release on Earth – just sterilization of the landing site
One thing my preprint contributes to this discussion of quarantine is that you can't contain, for instance, a crop disease with quarantine of human astronauts. There is a clear example of that, the two Zinnia plants that died on the ISS due to disease of plants brought there in the microbiome of an astronaut.
Text on graphic: Two Zinnia plants on the ISS were killed by the mold fusarium oxysporum - probably got there on an astronaut's microbiome
Human quarantine can't protect Earth from molds that might impact on our crops.
Mold growing on a Zinnia plant in the ISS. The mold fusarium oxysporum is thought to have got to the ISS in the microbiome of an astronaut
. Draft genome sequences of two Fusarium oxysporum isolates cultured from infected Zinnia hybrida plants grown on the international space stationTwo of the four infected plants died
. How Mold on Space Station Flowers is Helping Get Us to MarsIt would be impossible to keep a pathogen of terrestrial plants out of the terrestrial biosphere with quarantine of technicians or astronauts.
Also for some reason none of the planetary protection literature back to the origins of the topic ever considers the issue of a symptomless carrier like Typhoid Mary who had to be isolated through to the end of her life to protect others from typhoid despite never having symptoms herself.
With that ISS example, rarely the mold they carried to the ISS can make people sick. Based on these examples as well as the possibility of returning mirror life in the astronauts microbiome, I conclude that quarantine can’t be used to protect Earth from Martian samples. This seems to be something that should be at least considered.
This research is not yet peer reviewed because I haven’t yet submitted it to the journals but I think it needs to be considered and would surely pass peer review.
I cover this in my preprint about the draft EIS under
- Why quarantine can’t work to protect an orbital station with human technicians – example of wilted Zinniae which went moldy due to a crop pathogen likely brough to the ISS as part of an astronaut’s microbiom
- and following sections.
All these inaccurate cites and omissions make the draft EIS easy to challenge in courts
Skip to next section– and they didn’t respond to significant concerns raised by the public such as my own comment alerting them to the European Space Foundation study limit of 0.05 microns which is still not cited in the draft EIS
I hope you agree all these very inaccurate cites and omissions make the draft EIS extremely vulnerable to litigation.
I can’t see this going through the NEPA process unchallenged. Nearly every public comment says “don’t do it” or “test first”. There is significant public opposition to it.
As Rummel at al wrote
“Broad acceptance at both lay public and scientific levels is essential to the overall success of this research effort.”
page 96 of A draft test protocol for detecting possible biohazards in Martian samples returned to Earth.
They don’t have that and until they correct that, there is no way the mission can succeed.
How did this happen? Maybe it’s the engineering mindset as predicted by Margaret Race in 1996?
Skip to next sectionSo how did this happen? I think Margaret Race (of the SETI institute) hit the nail on the head way back in 1996.. She says scientists are likely to focus on
- technical details
- mission requirements
- engineering details
- costs of the space operations and hardware
General public are likely to focus on
- risks and accidents
- whether NASA and other institutions can be trusted to do the mission
- worst case scenarios
- whether the methods of handing the sample, quarantine and containment of any Martian life are adequate
See her:
, Planetary Protection, Legal Ambiguity, and the Decision Making Process for Mars Sample Return A
We see the results of this different focus in the report. It is just not something that greatly occupies the minds of the engineers and scientists who work on space projects, yet it is the main thing on the minds of members of the public.
Clear sign of this difference of focus - never set up a mechanism to deal with public responses with experts in legal, ethical and social issues
Skip to next sectionThis shows up clearly the issues with their failure to set up the mechanism to deal with public responses recommended by numerous sample return studies.
I cover this in my preprint about the draft EIS under
- Rummel et al recommend a planning agency set up in advance with experts in legal, ethical and social issues - Uhran et al recommend an advanced planning and oversight agency set up two years before the start of the legal process – and the ESF recommends an international framework should be set up, open to representatives from all countries - NASA don’t seem to have done any of this yet
Again it’s understandable engineers whose minds are focused on solving numerous complex technical difficulties with the mission might not understand why there is need to set up a planning and oversight agency two years before the start of the legal process. This wouldn’t help solve their engineering problems in any way whatsoever.
But for the general public, it is absolutely essential for the issues that matter most to them.
Showed no indication of reading public comments properly - no sign of reading the first sentence of my comment where I alert them to the 2012 ESF study which they still don’t cite which reduced the size limit from 0.2 to 0.05 microns
I mentioned many of these issues in my previous comments before they wrote the draft EIS itself, based on the preliminary documents. My first sentence cites the ESF Mars Sample Return study
Are you aware of the ESF Mars Sample Return study (Ammann et al, 2012:14ff)? It said "The release of a single unsterilized particle larger than 0.05 μm is not acceptable under any circumstances”. This is to contain starvation limited ultramicrobacteria which pass through 0.1 micron filters (Miteva et al, 2005). Any Martian microbes may be starvation limited.
This 100% containment at 0.05 microns is well beyond capabilities of BSL4 facilities. Even ULPA level 17 filters only contain 99.999995 percent of particles tested only to 0.12 microns (BS, 2009:4).
NASA show no indication that they read the first sentence of my comment. Or many of the other comments.
More precisely, in this EIS, they say they read our comments. But in their summary of what they say we said, they don’t mention many of the things we raised as issues. NASA can’t have given the public comments a thorough examination as required for the EIS process.
In my case they still don’t cite the 2012 ESF study and I can confirm they haven’t tried to contact me in any way to explain why they didn’t include it and it’s not mentioned in the draft EIS.
If I understand right, this will also count against them in a court case as it would show they haven’t considered objections by the public.
Likely to be litigated and if so likely outcome is to pause the project during the cases and may stop the project or request sterilization or some other injunction
Skip to next sectionI’m assuming you all agree NASA wouldn’t have a legal leg to stand on if this ever got taken to a court.
It’s my understanding that if litigation happens the likely outcome is that
1. it is likely that the justice would grant an injunction to pause the entire project during the court cases, for instance the future launches to Mars might be paused
2. If the litigation succeeds as seems very likely for this draft EIS, the justice will refer it back to the agency but can do so with a requirement for the project to be halted altogether
3. Or the justice can refer it back to the agency with an injunction, for instance a requirement to put in place precautions sterilize all samples from Mars before they can contact Earth’s biosphere – which would require intercepting the Earth Entry vehicle and sterilizing the sample if it has already been launched to Mars and can’t be redesigned to sterilize the samples on the return journey.
I am not a lawyer and I would welcome input from legal experts on what would actually happen if this cite is litigated and the litigation failed
I do know that cases under the NEPA process are often halted altogether or injunctions are given that constrain what is permitted.
I cover this in my preprint about the draft EIS under
- NASA’s Environmental Impact Statement is vulnerable to litigation on the basis that it doesn’t consider impacts of a sample return properly, doesn’t take account of the main issues mentioned by the Sample Return Studies and say things that contradict their conclusions – potential remedies include stopping the mission altogether or an injunction, e.g. to sterilize all samples before they contact Earth’s biosphere
That would be a great shame.
We can transform this mission into a mission of far greater interest for astrobiology and at the same time a mission with zero risk to the environment of Earth.
That should be the alternative to the mission. Not “no action” but a safe mission of great astrobiological interest.
However the sooner we do this the less the expense and the less the risk of unnecessary litigation.
Once it is accepted that we do need to consider potential for large scale effects on Earth’s environment - and Earth will be kept safe by a very extensive legal process before we could return unsterilized samples - apart from the issue of developing the necessary technology first
Skip to next sectionI know the guidelines now say that an EIS should be completed in less than a year. But I don’t see how that is possible in this particular case if the decision is made to try to return unsterilized materials while also agreeing that there is a low risk of large scale effects on Earth’s biosphere to be considered.
The papers by Urhan et al and Race are peer reviewed and everything in them checked out. Urhan et al’s second author is Cassie Conley, former NASA planetary protection officer. If what they say is correct, these things will be looked at very thoroughly.
Uhran, et al, 2019.. Updating Planetary Protection Considerations and Policies for Mars Sample Return.
As a result of the EIS process, numerous US agencies will make sure it is safe - who have nothing invested in the success of the space program - including the
- Department of Homeland Security,
- CDC (for potential impact on human health),
- Department of Agriculture (for potential impact on livestock and crops),
- Occupational Safety and Health Administration - for any rules about quarantine for technicians working at the facility
- Department of the Interior which is the steward for public land and wild animals which could be affected by release of Martian microbes
- Fish and Wildlife Service for the DoI who maintain an invasive species containment program and may see back contamination as a possible source of invasive species
- National Oceanic and Atmospheric Administration (NOAA)'s fishery program for sea landing in case it could affect marine life and NOAA fisheries
- Integrated Consortium of Laboratory Networks (ICLN)
International organizations like the WHO, FAO, and others would also be involved as well as international treaties
Skip to next sectionAlso several international organizations are likely to be involved such as the WHO (for potential impacts on human health globally if a new organism is returned that can be spread to other countries). If the worst case scenarios such as mirror life are seen as credible this would surely also involve the Food and Agriculture organization for potential impacts on global food supply and so on.
See:
Race, 1996, Planetary Protection, Legal Ambiguity, and the Decision Making Process for Mars Sample Return
Race says that experts will have challenges deciding in advance whether the sample should be classified as potentially:
• an infectious agent
• an exotic species outside its normal range
• a truly novel organism (as for genetic engineering)
• a hazardous material
The choices here would change which laws and agencies would be involved.
There are numerous treaties conventions and international agreements relating to environmental protection or health that could apply.
Including those to do with
• protection of living resources of the sea
• air pollution (long range pollution that crosses country boundaries)
• world health, etc
She also writes that many international treaties would be involved based on work by George Robinson.
Meanwhile, since this is a joint NASA / ESA mission, it involves ESA. Most of the ESA member states are in the EU (ESA, n.d.) so the EU will get involved.
This leads to a separate legal process in Europe, starting with the Directive 2001/42/EC (EU, 2001). I haven’t located any academic reviews for the European process, but as for the case in the USA, this would spin off other investigations which would involve the European Commission (Race, 1996).
In 1969, for Apollo 11, NEPA didn't exist. NASA did set up an interagency panel but their recommendations were kept secret and not made public before the mission. This panel asked NASA modify its plans, to keep Earth safe, but NASA vetoed them and all this happened in private discussions with no public involvement.
None of this would be permitted today. Today, NASA has no veto.
Any objections by the agencies would be made public and If any of these agencies think that NASA’s plans don’t keep Earth safe they can require NASA to change its plans or just stop the mission.
It’s far simpler to just sterilize samples returned to Earth and this is also a good precedent for other countries.
Value as a precedent for other countries like China for alternatives to “no action” that keep Earth 100% safe while preserving nearly all the scientific interest
Skip to next sectionChina currently plans to launch a mission possibly as soon as 2028, to return a sample by 2030. It would consist of two rockets, one with a lander and ascent vehicle, and the other with an orbiter and reentry capsule to return the sample to Earth, using two Long March rockets
. China is planning a complex Mars sample return mission
If China considers the Mars sample return to be potentially hazardous it is likely to be especially careful just as it has been especially careful with COVID.
The debate that is sure to happen with the NASA mission will help bring widespread awareness of the issues of a sample return and the need to be careful.
China’s mission is far simpler than the NASA one and similar to the proposal for NASA by the astrobiologist Chris McKay for a mission that does no more than land, gather a scoop of dirt and immediately return. He is the only astrobiologist I found in my literature search who proposes a sample return before in situ studies on Mars to look for life there first.
His proposal is a technology demo. In an interview with SpaceNews, he recommends we grab a sample of the Mars soil to show what we can do and return it to Earth. Spend one day on the surface. Design the simplest lowest cost way to return a sample from Mars, no Mars 2020, no rover. Just grab it and return
"The first thing is getting a mission that scoops up a bunch of loose dirt, puts it in a box and brings it back to Earth. If I was an astronaut, what I would be worried about is not the rocks. It’s the dirt. The discovery [by NASA’s Phoenix lander] of perchlorate in the dirt is cause to worry. It’s toxic, and the second cause to worry is the fact that it took us so much by surprise. There was no prediction or premonition that there would be perchlorate in the soil. The fact that it took us completely by surprise makes me wonder if there are other surprises in the soil. In fact, I would be surprised if there are no other surprises. Bringing back dirt is easy because it’s everywhere you land. You don’t need precision landing. You don’t need a rover. You land, grab some dirt and launch it back to Earth. The ground time on Mars could be one day."
He says we shouldn’t try to aim for just one sample return ever, and a perfect sample return. That it should be a first of many such missions. He says this argument falls on deaf ears.
"...I’ve said for many years that the sample return should be motivated by a combination of human exploration and science. The science community, I think, does itself a disservice by taking the attitude that there will be just one sample return ever in the history of the universe, so it has to be perfect. And a sample return mission that falls short of perfect shouldn’t be considered. I don’t understand where the logic is behind that. Let’s make a first sample return a quick and easy sample grab, demonstrate the key technologies. It builds enthusiasm for the idea of round-trips to Mars. It would also make getting a second sample return easier, both programmatically and technically. That argument falls on deaf ears when I try and bring it up in the community."
One of his main concerns is that there is no alignment at present between the NASA Mars strategy and astrobiology. The decisions are made by geologists who naturally recommend we study rocks.
"If we’re going to search for life, let’s search for life. I’ve been saying this to the point of exhaustion in the Mars community. The geologists win hands down as they are entrenched in the Mars program. The favorite trick is to form a committee to decide what to do. The people that are put on the committee, of course, are people who are funded to study rocks. So the committee recommends that we study rocks. They’ll say these rocks will give us the context of how to search for life on Mars. Then you say, well, that’s not right. But NASA Headquarters will say they asked the science community and they told us that this is what we ought to do. It’s kind of circular. The reason the committee told you that — it’s because you put a committee together of people who study rocks. It’s almost a Catch-22. "
He said that back in 2015, Q&A with Chris McKay, Senior Scientist at NASA Ames Research Center
There's another even lower cost proposal, the "Sample collection to investigate Mars" or SCIM mission. The proposal is to dip into the Mars atmosphere during its dusty season, and pick up a sample of dusty air, to return to Earth. It would use a "free return" trajectory. As soon as it leaves Earth's vicinity, it's on a trajectory to skim the Mars atmosphere and return to Earth with only minor course corrections after that
. Mars Sample Return Within This Decade
. NASA selects four Mars scout mission concepts for study
Video: SCIM Mission to Mars narrated
China's first mission may have a higher chance of returning present day life than the NASA mission as currently envisioned - because they plan to scoop up some dirt which could have viable spores from dust storms, or the life that Viking detected (if it did find life).
Also as Chris McKay envisions, the first samples returned from Mars may lead to many more as the technology to return the samples matures.
Perhaps China may be able to accelerate their legal process or bypass elements of it though they would still have the international treaties and responses of international organizations and other countries to deal with.
However, once this topic enters public debate widely, the public can be expected to raise many issues as NASA has already seen with the comments so far on their draft environmental impact statement
. public comments, MSR, PEIS
The general public in Chinese likely raise similar issues, which would get the attention of leaders in China, given their recent experience of COVID and the high level of importance they assign to matters of public health.
So I think on this topic we don’t need to think of China as being adversarial or likely to want to skimp on planetary protection. If the science is presented clearly and widely understood they will want to sterilize returned samples too.
So, we can hope for an international consensus that it is just sensible for now, to protect Earth 100% with sterilization. That is - until we know what is on Mars.
Need to bring scientists, the public and space colonization enthusiasts together
Skip to next sectionI believe we need to bring the scientists, the public, and the space colonization enthusiasts together. There is a large constituency of space colonization enthusiasts on Mars and we can accomplish much more if we can go forward working together with each other to solve the many problems for human exploration of Mars.
I will go into your arguments in a moment, but first I will outline my vision for the future, which I hope is an inspiring alternative to the ideas of the Mars society and SpaceX for the near future.
My vision for the future which i believe will lead to far more sustained interest in space exploration and settlement - starting with even more ambitious planetary protection exploring Mars from orbit in the spectacular HERRO orbit - even more interesting than the ISS orbit around Earth
Skip to next sectionI suggest we start with missions from Earth doing in situ exploration of Mars, followed by humans exploring Mars from orbit in a very rapid astrobiological survey - similar to the one you vision but done with 100% sterile rovers. They would explore in orbit by telepresence.
As you’ll know, this is an idea that’s come up often in the Mars exploration literature:
Buzz Aldrin’s plan:
- Aldrin et al, 2013. Mission to Mars (p. 173).
The Boeing “Stepping stones to Mars” mission:
- Hopkins et al, 2011, September. Comparison of Deimos and Phobos as destinations for human exploration, and identification of preferred landing sites
- Kwong, et al., 2011, September. Stepping stones: exploring a series of increasingly challenging destinations on the way to mars. In AIAA Space 2011 Conference, Long Beach, CA (pp. 27-29).
The HERRO mission
- Oleson, et al., 2013. HERRO mission to Mars using telerobotic surface exploration from orbit
- Valinia, et al., 2012. Low-Latency Telerobotics from Mars Orbit: The Case for Synergy Between Science and Human Exploration.
And Mars Base Camp
- Cichan et al, 2017. Mars Base Camp: An Architecture for Sending Humans to Mars
The easiest of all of these in terms of delta v. is the HERRO mission which could be the earliest, a sun synchronous near polar Mars orbit that’s easty to get to from Earth.
The HERRO orbit is a spectacular one, comes in close to the poles of Mars twice a day, near to each pole, then skims the surface than away again until Mars recedes to a small disk in the distance and then repeats. The astronauts get a few hours every day of close telepresence exploring the surface directly via robots that work like avatars in a computer game.
This is what it might look like from inside the spacecraft
Composite of photo from the Cupola of the ISS (Coleman, C, 2011) and Hubble photo of Mars (Hubble, 2003
In this video, I use a futuristic spacecraft called the “Delta Flier” in Orbiter as that was the easiest way to do it in the program I used to make the video. Apart from that, it is the same as the orbit suggested for HERRO.
https://www.youtube.com/embed/BftmbvBd5m4?feature=oembedVideo: One Orbit Flyby, Time 100x: Mars Molniya Orbit Telerobotic Exploration in HERRO Mission
I think an orbital mission like HERRO is of far greater sustained interest both for the public and for the astronauts than a surface colony where you see the same view from your window every day - with not even much by way of changes, very little even by way of weather, and it takes hours to put on a spacesuit if you do it safely, to get out of doors. The first footprints and the first flag would be of interest but there is a limit to how much interest there is in seeing the same landscape outside the module window every day of the year, with the monotony only relieved by occasional dust storms or dust devils.
But the HERRO orbit would be much like the ISS, where the astronauts see constantly changing landscapes outside of their windows. This greatly adds to the public interest of the ISS.
The HERRO orbit is a bit like the lunar gateway polar orbit but approaches Mars twice a day instead of once every 7 days as for the Moon.
Then setting up a base on Phobos, Deimos or both as with Buzz Aldrin’s “Mission to Mars”
Humans could also explore Phobos and Deimos which also have ISS like orbits around Mars. There again, they see a different view every time they look out of their windows towards Mars.
This would be like Buzz Aldrin’s plan - from his “Mission to Mars” book.
As he summarized it briefly in this interview
There are a lot of things really should be done before the first
people go down and it is so much more efficient without going into details ... A project manager said what they did in five years could have been done in one week if we had human intelligence in orbit so that we could control things with a second time to life instead of 15 minutes
From his book, Aldrin and David, 2013. Mission to Mars (p. 173).
Phobos is a way station, a perfect perch that becomes the first sustainable habitat on another world. From that mini-world, crews on Phobos can run robotic vehicles on Mars more directly, in a much shorter communication delay time than commands sent from faraway Earth. Robotic stand-ins for astronauts will ready the habitats and other hardware on the Martian surface, in preparation for the first human crew to arrive on Mars. That’s my judgment. My theory right now is that somebody piecing together hardware on Mars through telerobotics on Phobos is the right person to later lead the first landing mission on the red planet.
Phobos and Deimos are, in a sense, offshore islands of Mars, discovered in 1877 by Asaph Hall at the U.S. Naval Observatory in Washington, D.C. They were tagged with names from Greek mythology: Phobos means “fear,” Deimos, “terror.” In the future these Martian moons are likely to symbolize just the opposite: courage and security.
By placing a crew-occupied laboratory/control station on either Phobos or Deimos, an assortment of probes, penetrators, and rovers can be controlled on Mars. Far more of the planet can be reconnoitred, more so than a landed crew could achieve. After all, Mars is vast. It’s a huge planet with a lot of real estate, some of it very hazardous in terms of crevasses, caves, steep hills, giant canyons, and high mountains. Better to lose a robot or two than have a person face a deadly predicament.
On one hand, robots are able to cope with the surly climes of Mars while carrying out boring, risky, or dull jobs. On the other hand, humans bring perception, speed and mobility, dexterity, and an inquisitive nature. Combining the two is opening up a new paradigm in space exploration. “Telepresence” makes use of low-latency communication links that can put human cognition on other worlds. Low-latency yields the appearance of “being there” in a way that is near real-time believable. The ability to extend human cognition to the moon, Mars, near-Earth objects, and other accessible bodies helps limit the challenges, cost, and risk of placing humans on perilous surfaces or within deep gravity wells.
Maintaining the biological value and interest of Mars with 100% sterile rovers - made feasible by engineering studies for Venus
Skip to next sectionThen I believe that to maintain the biological value and interest of Mars in early stages of exploration, we need 100% sterile rovers, We have that technology developed for Venus landers, a complete rover made with modern heat tolerant electronics that can run indefinitely at 300 C with active cooling. these electronics are widely used in electric cars, to monitor furnaces, for some jet engine parts and so on so they are well understood and robust.
For our Mars missions we could heat the rover for months during the journey to Mars then operate it at normal temperatures on Mars. There would be initial expense in the design, sourcing components for it and so on, but much of the work is already done for Venus and once done there would be little overhead after that. The expense of heat tolerant alternatives for all the components would be small compared to the overall cost of a space mission.
So, I actually advocate a far higher level of planetary protection than we have today.
I expand on these ideas in my preprint here, which I plan to submit to astrobiology journals in the near future.
My background and my preprint about planetary protection for NASA’s Mars sample return mission (work in progress, hope to submit it soon)
Skip to topI have a reasonably understanding of the literature they cited because I’ve been working on that paper NASA and ESA are likely to be legally required to sterilize Mars samples to protect the environment until proven safe ... specifically on planetary protection for NASA’s Mars sample return mission since 2020.
I trained as a mathematician, not as an astrobiologist, but astrobiology is very multi-discipline. I think what I bring most to the topic was to bring together results and ideas across the vast range of many different disciplines spanned by the subject. I was invited to give a talk on astrobiology to a small conference in Oxford where some of the world’s leading astrobiologists also spoke. My presentation for that conference is here "Super Positive" Outcomes For Search for Life In Enceladus and Europa Oceans - Robert Walker
I was encouraged to write a paper on astrobiology by an astrobiologist friend some years ago. That lead to the my original preprint. I haven’t yet submitted it to any astrobiology journals.
I also have a blog on Science 2.0 where I write blog posts on many topics and have often blogged about planetary protection in the past.
For some of my blog posts at Science 2.0 on this topic of protection of Earth for a Mars sample return:
- . Will First Mars Astronauts Stay In Orbit - Tele-operating Sterile Rovers - To Protect Earth And Mars From Colliding Biospheres?
- . Let's Make Sure Astronauts Won't Extinguish Native Mars Life - Op Ed
- . Likely 2040 Before Mars Samples Returned Safely, Legally -Yet Not Likely To Return Life - Needs To Be Detected In Situ First
- . Protecting Mars - And Earth - From What - And Why Bother? Our Inheritance Of Unopened Astrobiological Treasure Chests
And here is my free self-published online book on planetary protection for the general public, where I expand on many of these themes.
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