When it comes to space colonization, Mars is at the forefront of modern exploration. Meanwhile, our nearest celestial neighbor - the Moon - is seemingly overlooked. And that’s, in part, because the Moon isn’t exactly a haven for humanity. The lunar surface is covered with dead volcanoes, massive craters and potentially poisonous dust. It’s also constantly bombarded by space rocks raining down on its surface due to its very thin and weak atmosphere known as an exosphere. On top of that, this ultra thin layer of gases doesn’t provide any protection from the sun's radiation. But some scientists believe this wasn’t always the case. Recent NASA findings show that there might have been a time when the Moon had a prominent atmosphere, and it could increase the chances for colonization.
Billions of years ago, after the formation of the inner solar system, it’s believed, that the young planets and the moon were pummeled by space rocks and other leftover planet-building material. The period known as the Late Heavy Bombardment or LBH is thought to have lasted millions of years, and damage from this violent period was seen in craters on some of the inner planets and the Moon.
There, the LBH triggered a series of volcanic eruptions. Lava filled the lunar craters, creating seas that stretched for hundreds of kilometers across its surface. During this period, it is thought that the lunar lava emitted gas components or volatiles like carbon monoxide, sulfur, hydrogen and oxygen. As the lava spread, the volatiles accumulated and formed a transient atmosphere. The ancient atmosphere was believed to be much thinner than Earth’s current atmosphere, but 1.5 times thicker than Mars’ current atmosphere.
The eruptions lasted for about 70 million years, and it’s estimated that trillions of gallons of water was released during this period. As the atmosphere started to thin out, the volatiles were either lost to space or became part of the surface of the Moon. Researchers believe it’s possible that a significant amount of water may have made its way to the lunar poles and could be trapped in permanently shadowed regions. In fact, NASA’s new analysis quantifies a source of volatiles based on lunar samples collected during the Apollo missions. And these volatiles could provide key resources - like water, air and fuel - for extended moon missions and beyond.
So while Mars is still a frontrunner when it comes to colonization, revelations about the Moon’s past and its potential presence of water continue to prove that there is still a lot more lunar exploration needed before we count the Moon out.