One of the biggest missions NASA is working on today is getting prepared for the Artemis mission that will return humans to the moon. NASA recently requested science white papers to help the agency design a framework for the Artemis mission’s science operations. One of the proposals suggests astronauts on the mission should bring back samples of lunar ice and samples of lunar regolith.
By bringing lunar ice back to earth, scientists may be able to figure out where the moon’s water came from. Scientists speculated that ice might exist on the moon since the days of the Space Race in the 60s and 70s. As for where the ice came from, scientists believe it could have been deposited by comets or produced by interactions between hydrogen and oxygen-rich rocks.
The first clear evidence of water ice on the moon was discovered in the 1990s by the Lunar Prospector spacecraft. That spacecraft launched in 1998 and spent over a year and a half mapping the moon’s surface. It detected high concentrations of hydrogen in the regolith near the polar regions with a depth of about 3.3 feet during its mission.
The Indian spacecraft Chandrayaan-1 that orbited the moon in 2008 and the Lunar Reconnaissance Orbiter in 2009 confirmed the presence, particularly in the permanently shadowed craters on the moon’s south pole. A later mission called the Lunar Crater Observation and Sensing Satellite inspected the southern Cabeus crater and found water concentrations up to approximately five percent by weight.
The spacecraft also found an abundance of other volatiles, including hydrogen sulfide, carbon monoxide, and ammonia. The hope is that there is enough water ice on the moon to sustain a human colony and crewed missions by providing drinkable water and the ability to produce rocket fuel locally.