The discovery of “significant amounts” of water in moon rock samples collected by NASA’s Apollo astronauts is challenging a longstanding theory about how the moon formed, scientists say.
Since the Apollo era, scientists have thought the moon came to be after a Mars-size object smashed into Earth early in the planet’s history, generating a ring of debris that slowly coalesced over millions of years.
That process, scientists have said, should have flung away the water-forming element hydrogen into space.
“I still think the impact scenario is the best formation scenario for the moon, but we need to reconcile the theory of hydrogen,” study leader Hejiu Hui, an engineering researcher at the University of Notre Dame, told SPACE.com.
The levels of hydrogen bode well for efforts to establish a base on the Moon.