Water is released from the moon during meteor showers, when micrometeoroid impacts breach the dry lunar surface and eject water molecules from a hydrated layer below.
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.