From Len Mann, Gerrards Cross, Buckinghamshire, UK
I have digested the explanations for why trying to live on Mars is a bad idea. Very good points are made, but one important thing is missed. One day, a disaster will befall Earth that will most likely wipe out the human race. It might be an extinction type asteroid impact, a nuclear war, a pandemic, global warming or something we haven’t thought of yet. If you think we should do our very best to preserve our species, then I believe that Mars is pivotal (16 November, p 48).
We don’t even need to fully colonise it. When visiting Mars, people would need to stay for at least a year because of orbital dynamics. A transient colony of a few thousand could be maintained on an ongoing basis. At least then we would have the possibility of recolonising Earth after a disaster.
