Scientists' theories on how the moon developed may not hold water—because it seems that the moon itself once did. That's what researchers are saying after new analysis of Apollo mission moon rocks, the Los Angeles Times reports. The widely-accepted story is that the moon is the result of debris from Earth, knocked off after the planet was hit by a Mars-sized object. But heat involved in the process would have made the moon an extremely dry place.
Previous signs of water on the moon, found in glass beads, were thought to have come from elsewhere. But a new study of the rocks finds a lot more water than expected—about 6 parts per million. The researchers say this could be "native" water, the result of an ancient magma ocean on the moon. "It opens up quite a mystery as to how the moon came through what we think was a very hot genesis process with this much water," says an outside expert. That water could also aid future people who arrive on the moon for a "more permanent" stay.