Look at Earth from a Martian perspective

http://www.theguardian.com/science/2015/feb/20/look-at-earth-from-a-martian-perspective

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Todd Huffman says we should refrain from sending humans to Mars until it can be determined if Mars has an independent biosphere of its own (Letters, 18 February). This is wrong for two reasons. First, if life of any description is found on Mars, it is virtually certain to be related to life in Earth’s biosphere due to the two planets exchanging rocks through asteroids and cometary impacts. Indeed, it has been suggested that, in the early history of the solar system, Mars may have been a more life-friendly planet than Earth and could well be where life originated before being transported to Earth.

Secondly, if there is any life on Mars it is almost certain to be no more advanced than a bacterium or at best a worm. Surely a project as exciting as sending humans to Mars should not be cancelled for fear of upsetting a few hypothetical worms or bacteria, which, even if they do exist, will already have had contamination from Earth’s biosphere, through natural exchange of crustal material between both planets.David MothBraintree, Essex

• Nothing interesting is happening on Mars. When Nasa asked James Lovelock about life on Mars, he reversed the question, asking: “If one were on Mars could one deduce anything about Earth?” The answer is that even from Mars it would be obvious that something very unusual was happening here. Our highly unstable atmosphere could not persist for long unless it was being continuously replaced by a vast mass of living organisms.

From this distance we can analyse the Martian atmosphere and deduce that sending humans to Mars is a total waste of resources. It would be better to learn something about sustaining life on Earth.Richard AhrensWatford, Hertfordshire