In the never-ending search for life beyond Earth, astronomers tend to look far, far away, but it seems our closest neighbor may have once been a habitable world, too. No, I’m not talking about Mars, but the Moon. According to a new study published in the journal Astrobiology, Earth’s moon may have been a pretty nice place for life to take root many ages ago.

In the study (PDF), researchers suggest that conditions on the Moon a few billion years ago could have been life-supporting. The Moon was a very different place then, and rather than desolate, dusty expanses of nothingness we see today, the sphere was actually bustling with geological activity.

In the period immediately following the formation of the Moon, it was likely producing an abundance of water vapor which, scientists say, may have been enough for larger bodies of water to collect on its surface. Combined with other gasses released by the young moon, an atmosphere likely formed that would have offered protection against solar radiation that would have snuffed out new life.

Obviously, things are much different on the Moon today, and it’s been billions of years since it would have been capable of supporting life as we know it. However, it’s quite interesting to imagine that Earth’s trusty satellite could have had an ecosystem all its own.

To be clear, scientists don’t actually have any evidence that the Moon had any form of life on it at any point in time, even in the tiniest microbial forms. The fact that conditions on the Moon may have been supportive of life doesn’t mean any living organisms were actually present. Still, researchers hypothesize that a planet such as Earth may have the ability to spread its early primitive life to other nearby worlds, such as a moon, via asteroids or meteor strikes that cause biological material to be launched into space.

If such a thing actually happened billions of years ago, we may find evidence of simple life forms near areas of the Moon that were known volcanic hot spots, and it may just be waiting to be found.