Mars is Earth like in some ways, but in other ways it's very different with its global dust storms every two years, its thick sheets of dry ice at its ice caps in winter. Any fresh water is close to its very low boiling point in the near vacuum. And the eccentric orbit also has a big impact on its seasons. So how do its seasons work exactly and what effect does this have on its climate?

Yes, a thousand of them indeed. The asteroid belt, and Near Earth Asteroids. I don't mean living on them like the little prince:

The Little Prince

That's not very practical without an atmosphere.

Nor living inside them as some suggest.

But rather, using materials from the asteroid belt and first, from the close Near Earth Asteroids, to build large habitats following the Stanford Torus design and others.

NASA currently has Mars sample return as their priority flagship mission not just for this decade but for the next one as well. They were recommended to do this in the 2012 decadal review. It is good for geology, nobody doubts that. But it is motivated mainly by the search for ancient life on Mars. Some exobiologists have warned that it is likely to be no more conclusive than the Mars meteorites we already have. They regard it as is little more than a technology demo for the search for life.

The longest time anyone has spent in space is just over fourteen months. So far, astronauts have recovered surprisingly quickly, even after the longest duration spaceflights. Within a few weeks they are almost back to normal health. There are some longer term effects, on load bearing bones, which may take a couple of years to clear up, and very rarely, permanent effects on the eyes.

But what about longer periods in space than that? Their condition continually deteriorates for as long as they are in space and so far nobody has spent as long as two years in space; the record is fourteen months. So the question is still wide open for longer duration flights.

First let's look at what we know already.

On February 15th, 2013, as the approach of asteroid (367943) Duende was being closely monitored,  something far more alarming happened. Duende approached the Earth was expected to pass nearly 27,700 km above the Earth's surface, well inside the boundaries of the ring of geosynchronous satellites but nearly perpendicular to it, but then the Chelyabinsk superbolide entry occurred, followed by the explosion and the fall of the large meteorite in the Russian Lake Chebarkul. 

It caused damage to hundreds of buildings and injuries to nearly 1,500 people. 

The Ordnance Survey (national mapping agency for the UK) has just released their first map of a region on another planet. It's a high resolution relief shaded contour map, and includes the area of Mars where ExoMars will land in 2018. Here is a close up view of it with the ESA landing ellipse in Oxia Planum superimposed. 

Preview of the full map - low resolution, again with landing ellipse.

September 14th 2015, 09:50 GMT. A far spread out distortion of space crossed earth's path. The distortion had traveled at the speed of light for more than a billion years, all along the way spreading out spherically and diluting its energy density inversely proportional to the spherical area covered. Still, when distorting the space occupied by earth, it did so with a peak power equal to the total electrical power consumption of human mankind.

Earth responded by undulating, expanding in one direction, shrinking in a perpendicular direction, and then reversing. And reversing. The frequency of undulation increased like a coin wobbling on a table top. And then suddenly, like a wobbling coin coming to rest, space became quiet again, and earth's shape stabilized.

The undefined blanket term "dark matter", what must exist in the universe to account for missing mass, is invoked for just about everything, and so a lot of claims are made affirming they have evidence for it. But one claim, that bursts of gamma rays are such, is instead  other astrophysical phenomena such as fast-rotating stars called millisecond pulsars, according to two new studies in Physical Review Letters.

Previous papers suggested that gamma rays coming from the dense region of space in the inner Milky Way galaxy could be caused when invisible dark matter particles collide. But using new statistical analysis methods, two research teams independently found that the gamma ray signals are uncharacteristic of those expected from dark matter. 

Everyone has started to call this new proposed planet X: "Planet nine" as in the original announcement. Even Wikipedia has titled its article on it "Planet Nine". But it's a poor name for a planet if you think about it. Why not just call it "Planet X"? Or find some new name, like Nemesis and Tyche as was done for previous planet X candidates.  None of the previous candidates for Planet X were called Planet + some number, and with good reason. There is no way that we can know it will be planet 9. 

As someone who is keen on astronomy, I am of course keen on the Thirty Meter telescope myself. And I've heard those arguments of the astronomers, about how it is an ideal site for astronomy, about the value of the astronomy that can be done with this telescope and so on. But I've also heard the other side too.

There are many telescopes on the summit already, so it's not like they are saying not to build telescopes at all up there.


What you might not realize at first is quite how huge it is - it's difficult to get a sense of scale from the images:

It's higher than the Niagara falls.