According to our evidence, Mars had liquid water for a very long period,
I went to check this—maybe liquid water is a short-term enough thing that its mere presence is still weak evidence for an active biosphere, but apparently one timeline puts liquid water as present in large quantities for >600 million years. Bleh.
I went to check this—maybe liquid water is a short-term enough thing that its mere presence is still weak evidence for an active biosphere, but apparently one timeline puts liquid water as present in large quantities for >600 million years. Bleh.