The nearby star Proxima Centauri hosts an Earth-sized planet (called Proxima b) in its habitable zone but the star seems nothing like our sun. It's a small, cool, red dwarf star only one-tenth as massive and one-thousandth as luminous as the sun. However, new research shows that it is sunlike in one surprising way: it has a regular cycle of starspots.

Starspots (like sunspots) are dark blotches on a star's surface where the temperature is a little cooler than the surrounding area. They are driven by magnetic fields. A star is made of ionized gases called plasma. Magnetic fields can restrict the plasma's flow and create spots. Changes to a star's magnetic field can affect the number and distribution of starspots.

You may have heard that the Moon is hopeless for gardening and for growing crops, and that Mars is the "go to" place for a prospective astronaut gardener. But is it? As it turns out, the Moon has some advantages over Mars, especially if you can plant your garden in a habitat or greenhouse on its summits of sunlight at the poles.

Yes, it is rather chilly there, at -30° C (-22 °F), but there is no weather, good or bad, and the vacuum of space is a good insulator (like a thermos flask). The temperature at the poles is steady, varying by only 10 °C (18 °F) up or down. That's warm enough to keep a well insulated habitat or greenhouse at a comfortable temperature of 20° C (68 °F) year round with sunlight piped in from solar collectors.

When I wrote my kindle and online book Case for Moon First, I was surprised to find that the Moon is resource rich, and often beats Mars in habitability comparisons.  Yet photos of Mars released to the press look so much more Earth-like than the Moon, because of the brightening of the landscape and boosting of blue in the scene (white balancing) done to help geologists read the rocks.

This is a news story that broke recently, on the idea that Elon Musk's plans would violate the Outer Space Treaty. The articles I've read so far focus on property rights and the  provisions in the OST that rule out ownership of territory. But that can be fixed with future legislation, especially since it's not really the land but the habitats that are of most value, and ownership of those is already covered in the OST . So far none of them have mentioned by far the toughest legal and practical obstacle, which is planetary protection of Mars from Earth microbes to preserve its science value for the future of mankind. That can't be fixed by passing new laws. Elon Musk says the mission would be dangerous, with colonists risking death, especially the first ones.

I've just been listening to Elon Musk's much anticipated talk about his vision for colonization of our solar system. Many find this idea inspiring, that by technological means, we can become a multiplanetary species. 

Here is the talk, in case any of you haven't seen it yet.

For a summary of the technical details he revealed in the talk, see this article on

So now we know what the news is, as expected, Hubble has found new evidence of possible plume activity on Europa. In a series of ten observations, they saw them on three occasions. Here are the images they created.

The possible plumes are in the seven o'clock position, not far from the South pole - though the central image here has another possible plume that's close to the equator.

Interestingly, they spotted them in the same position as the previous plume detection in 2012:

I've already done a petition to journalists on the issue of dramatized reporting of doomsday stories that make young children and vulnerable adults suicidal. This is another petition on the same topic, this time to Youtube. The  petition is to remove the ads from doomsday videos on the sane grounds that these videos make vulnerable young children and adults scared and suicidal and the ads provide a financial incentive to youtube users to make and reupload them.

KIC 8462852 (or Tabby's star) made headlines in October of last year because of  very deep and very unusual drops in its brightness, which led to speculation that the star might be home to a Type-2 alien civilization. Since then, new discoveries (e.g. Montet and Simon, 2016) have continued to baffle researchers.

There are various hypotheses for the origin of the Moon but a chemistry analysis says it has disproved the leading one - that a low-energy impact left the proto-Earth and Moon shrouded in a silicate atmosphere. Instead, they say, a much more violent impact vaporized the impactor and most of the proto-Earth, expanding to form an enormous superfluid disk out of which the Moon eventually crystallized.

This is an intriguing paper which has hit the news, see  Planet Nine Could Doom Our Solar System - If It Exists. If our solar system has a planet in a distant orbit, way beyond Neptune, such as the planet X candidates, it could lead to instability of our solar system far into the future. That's a rather unintuitive result - how could such a distant planet make any difference to our solar system's stability? It's not only intriguing, it might also provide the solution to a major puzzle about white dwarf stars.