A smattering of water is buried deep inside the Moon and it arrived during the satellite’s very early history, a new study concludes, when asteroids plunged into its churning magma oceans.
How and when water got trapped in volcanic lunar rocks is a huge and open question for planetary scientists.
This international team has compared the chemistry of Apollo mission samples with various types of space rock.
They say that icy, early asteroids were the likely source of most of the water.
After such impacts the Moon’s developing crust could have trapped the water in the cooling magma.