Asked by Mia Grover
It is possible that we might have been able to live on Early Mars, although we still do not know enough about the early atmospheric conditions to be sure.
Observations of river channels and ocean beds on Mars show that the atmosphere was once much thicker so liquid water could exist. Turn back the clock to a time when Mars still had a magnetic field, able to deflect high energy charged particles that would otherwise strip the atmosphere, we would find a Mars with a much thicker atmosphere.
Research by scientists studying the difference between surface rocks and Martian meteorites suggests that about 3700 million years ago, Mars may have had an oxygen-rich atmosphere. So, for a short time at least, Mars may have been habitable for humans.
Answered by Sophie Allan from the National Space Centre