The long, shallow grooves lining the surface of Phobos are likely early signs of the structural failure that will ultimately destroy this moon of Mars.

Orbiting a mere 3,700 miles (6,000 kilometers) above the surface of Mars, Phobos is closer to its planet than any other moon in the solar system. Mars' gravity is drawing in Phobos, the larger of its two moons, by about 6.6 feet (2 meters) every hundred years. Scientists expect the moon to be pulled apart in 30 to 50 million years.

"We think that Phobos has already started to fail, and the first sign of this failure is the production of these grooves," said Terry Hurford of NASA's Goddard Space Flight Center in Greenbelt, Maryland.

In 2006, a tiny percentage of astronomers took it upon themselves to change the definition of "planet" and so Pluto was out. Chaos ruled, the 237 astronomers who made the ruling dug in their heels, and for the most part they were ignored.

After all, there are now nearly 5,000 planetary bodies orbiting stars other than ours. But astronomers don't know what exactly we should call them. Today at an American Astronomical Society meeting, UCLA professor Jean-Luc Margot described a simple test that can be used to clearly separate planets from other bodies like dwarf planets and minor planets and replace the  "definitional limbo" those bodies are in. 

Let's declare Pluto as a dwarf or sub dwarf planet AND a planet! This is about the vexed question of whether Pluto is a planet or not. Yes the International Astronomical Union "settled the question" but I'm not sure their decision is one that will work all the way into the future, for instance if we find Earth or Neptune sized objects beyond Pluto. And it also stretches language in an awkward way to say that Pluto is a dwarf planet but not a planet - and the English word "dwarf" seems to have little to do with the concept of clearing your neighbourhood.

SETI has listened to KIC 8462852 for two kinds of signals and found nothing stronger than an intensity of 100 Jy (Jansky). They looked for purposefully broadcast narrow band signals and a wide band omnidirectional signal not purposefully sent.  Their first observational pass lasting two weeks found , in their words, "To summarize these observations, we estimate an upper limit for anomalous flux from KIC 8462852 to be 100 Jy in a 100 kHz band over the frequencies displayed." 1  Put another way either no one is transmitting, or no one there is transmitting anything strong enough for us to detect at the distance KIC8462852 is from us (about 1500 light years).  

Weather patterns in a mysterious world beyond our solar system called
PSO J318.5-22
have been revealed for the first time. Layers of clouds, made up of hot dust and droplets of molten iron, have been detected on a planet-like object found 75 light years from Earth, researchers say. 

Findings from the study could improve scientists' ability to find out if conditions in far-off planets are capable of sustaining life, the team of astronomers suggests.

They used a telescope in increasingly-popular Chile (Hawaii and Arizona in the U.S. long ago declared white-collar astronomy and a mandated lack of light pollution to be environmentally hazardous) to study the weather systems in PSO J318.5-22, which is estimated to be around 20 million-years-old. 

I got many comments on last week's Nibiru article from some very scared people. They needed a lot of reassuring that it was indeed a hoax and not real, and brought up many topics to discuss such as lens flares, hoaxes, double sun videos, rare sun mirages, and the status of the astronomical search for various versions of planet X. Why are astronomers so sure that Nibiru is nonsense?

Astronomers have discovered an adolescent protostar that is undergoing a rapid-fire succession of growth spurts. Evidence for this fitful youth is seen in a pair of intermittent jets streaming away from the star's poles.

Known as CARMA-7, the protostar is one of dozens of similar objects in the Serpens South star cluster, which is located approximately 1,400 light-years from Earth. This clutch of nascent stellar objects was first detected by and named for the Combined Array for Research in Millimeter-wave Astronomy (CARMA) telescope.

In the film version of "The Martian", the main character is trapped on the red planet and is forced to figure out how to grow food. He declares he is going to "science the s--t out of" the issue before instead engaging in regular old agriculture mixed with some engineering.

But science may soon help, researchers have discovered a gene that could open the door for space-based food production. Professor Peter Waterhouse, a plant geneticist at QUT, discovered the gene in the ancient Australian native tobacco plant Nicotiana benthamiana, known as Pitjuri to indigenous Aboriginals tribes, which has been used for decades as a model plant upon which to test viruses and vaccines.

Science fiction stories often suggest that ETs, and our future selves also, would be expansionist, colonizing the galaxy, taking over worlds, and so forth. It's natural enough, because we are expansionist ourselves. But it's actually quite easy to see that ETs simply can't have expanding populations, at least not for very long. Not if they are anything like us. 

It's a simple calculation which I covered before. If their doubling time is once a century, say (for  ease of calculation) - then in a thousand years, their population multiples by a little over a thousand (two to the power ten). So after two thousand years it has multiplied by a million, by a billion after three thousand years and so on.

Sorry, I accidentally made two copies of this article with different titles. And both have comments, so not sure what to do.

Unless you want to read the comments here, please visit the newer copy, Why ETs Won't Need to Colonize or Expand.