Scientists have discovered that water is being released from the Moon during meteor showers. When a speck of comet debris strikes the Moon it vaporizes on impact, creating a shock wave in the lunar soil. For a sufficiently large impactor, this shock wave can breach the soil’s dry upper layer and release water molecules from a hydrated layer below. The LADEE spacecraft detects these water molecules as they enter the tenuous lunar atmosphere, with peaks in the water signal correlating to known meteor showers on Earth. The discovery of water just beneath the Moon’s surface provides a potential resource for future exploration, and it improves our understanding of the moon’s geologic past and its continued evolution.

NASA