From Harm Schoonhoven, Utrecht, The Netherlands
A colony on Mars will fail as a back-up plan after a catastrophe on Earth. It is hard to see how it could repopulate Earth with a significant number of people. Returning to Earth from space is a logistical nightmare at the best of times and requires functioning landing sites or splashdowns, with rescue by ship or similar (Letters, 28 December 2024).
A Mars colony will be totally dependent on a technologically advanced society on Earth and is doomed without it. As far as I know, colonists aren’t expected to forge their own screwdrivers from Martian material. More broadly, life has thrived here for billions of years without us and will do so long after we become extinct.
