This idea goes back in 1967. James Lovelock, originator of the Gaia hypothesis, found a way to use a planetary atmosphere to detect life. He suggested that we look for simultaneous presence of pairs of gases like oxygen and methane that react together. We can also search for gases such as oxygen above  levels expected from abiotic processes.

As  far as we can see, Mars atmosphere seems to be close to equilibrium in this way. So when Viking I and II landed there in 1976, and found a barren desert-like surface, it seemed natural to conclude that there is no life on Mars.

I thought I'd post this because there are many who haven't followed the latest findings, who still think that present day life on the surface of Mars is absolutely impossible because of UV light, ionizing radiation, and perchlorates, and because the atmosphere is in almost perfect chemical equilibrium. 

That is indeed what most scientists believed, prior to about 2008. But it is now generally agreed in the field that if there do turn out to be nutritious warm and wet habitats on the surface of Mars, they will be habitable. 

The UAE plans its first Arab spaceship to Mars in 7 years. What's more, they plan to land it on Mars. With this, they are aiming high indeed, as Mars is probably the most difficult place to land a spacecraft in the inner solar system.

I have no idea what their plans are, but it could be a wonderful opportunity to do something truly astonishing - and fly some of the innovative light weight Mars craft that have been developed over the years.

It's often said that if we do make contact with Extra Terrestrials (ETs), e.g. detect a radio transmission from a distant galaxy through SETI, that maths would be one of the few things we would have in common with them. But - how similar would their maths actually be to ours?

Modern maths- with its many sizes of infinity and logical paradoxes, has lead to much debate and puzzlement over the last century or so. Would this be the same for ETs? And would it lead to many different ideas about maths and the philosophy of maths, as we have here, or would they find some other solution none of us have thought of?

Will anyone own land in space? Could an individual, company or country claim the Moon? Will we have countries in space, organized by ideas and religions, and territories just as we have on Earth? Will they go to war with each other over territories, resources or ideas as they do on Earth?

Look at this carefully, and you find that there are various things about the space environment that make a difference from the way things work on the Earth. Many of our Earth based concepts may be impossible to apply in space or may need to be radically changed.

Kim Stanley Robinson in his famous Trilogy Red, Green and Blue Mars describes a science fiction future with Mars changing colour to green and then to blue. But what also about snowball white after a failed terraforming attempt? Or, what about purple, or black (or darker in colour)? Perhaps you can think of other colours it could turn as well?

I thought this would be a great way to explore some of the complexities of planetary transformation, to imagine the possible future colours of Mars - depending on human actions, deliberate or accidental.