The moon's interior may harbor 100 times more water than previous estimates, according to a new study that took a fresh look at samples of moon rocks collected by Apollo astronauts nearly 40 years ago.

The researchers determined that the lunar water likely originated early in the moon's formation history, suggesting that it is, in fact, native to the moon.

Scientists at the Carnegie Institution's Geophysical Laboratory, and other colleagues, said it's likely that the water was preserved from the hot magma that was present when the moon began to form – some 4.5 billion years ago.