Mars is extraordinarily cold and dry, like our most arid deserts. Harsh but possibly not totally lifeless. There is a chance of life there, hidden away perhaps in thin layers of brines just a couple of centimeters below the surface, or as spores within the dust. Our astronauts will be covered in microbes from Earth too and our habitats filled with life. What happens when life mixes together from these two biospheres?

This is a debate hosted by the SETI institute between Robert Zubrin, founder and head of the Mars Society, and one of NASA’s former planetary protection officers, John Rummel. They debate the requirements of the Outer Space Treaty of 1967 to protect both Earth and other celestial bodies like Mars from any harmful effects from the exchange of living organisms between the planets on our spacecraft.

This is another of those sensationalist doomsday stories in the red top tabloids scaring people. The stories say that we are 100% certain to be hit by an asteroid. Well, yes, for small asteroids, but we are 100% certain to be hit by lightning too, many times a year. Your chance of dying of an asteroid impact is far less than that of dying of a lightning strike, 10,000 times less likely.

ESA have just signed a letter of intent to co-operate with NASA on a Mars sample return mission (see Agencies aim to bring back rocks from Mars). I hope this does not mean a change of focus for ESA, from in situ searches, to a sample return. This expensive NASA program is more of a geological sample return and technology demo than an astrobiology mission. It's not likely to resolve any of the central questions in astrobiology. Yet there is so much involved in ensuring that Earth's environment is protected, both legally and technically, that  it is unlikely that they are ready to return an unsterilized sample to Earth before 2040.

The reason we know so little about the polar regions is not lack of interest. The polar regions are of great interest, for instance the Martian dry ice geysers in Richardson crater, one of the most interesting dynamic processes on Mars and the polar regions also have astrobiological interest too. There are potential habitats there that might even have fresh liquid water within 7 cms of the surface, beneath clear ice - of all the unexpected things to find on Mars with its near vacuum atmosphere!

These channels specialize in uploading evidence of 'Nibiru', a modern myth, a planet that supposedly is about to hit Earth or fly past, always in the near future. This will seem absurd to you if you have a decent scientific background, but these people do not. They missed out on astronomy or science at school and some are very young. Some teenagers as young as 13, the minimum age for Facebook are in a perpetual panic over these videos, and we hear from their parents of even younger children who got terrified by these videos, sometimes as young as 8 years old.