Was Earth’s Moon once habitable?
While much of the focus for habitability is on the icy moons in the outer Solar System, our own Moon could be a surprising target too. Findings suggest that its rocks are richer in water than we thought, and it’s estimated that about 3.5 billion years ago it had an atmosphere about one per cent as thick as ours, thereby thicker than that on Mars. Put this all together and scientists think the Moon could have supported liquid water for millions of years around this time, during a period when life on our own world – which was possibly delivered by comets or asteroids – was only just starting to develop. It could be that life on Earth spread to the Moon via meteorite impacts, a process called lithopanspermia. But there are no clear signs of bodies of ancient water on the Moon, so this idea will require further investigation in future.
The young Moon could have supported water for a short amount of time