Recent studies have found that the amount of water in moon rocks varies by region.
The findings could help researchers determine how water originated on the moon and how it was redistributed across the surface, a University of Hawaii ‑ SOEST news release reported.
The water is trapped in volcanic glass or mineral grains inside lunar rocks. The team found that rocks originating from areas in the lunar interior contained more water than those from other places.
"Basically, whatever happened to the Moon also happened to the Earth," said Katharine Robinson, lead author of the study and Graduate Assistant at the University of Hawai'i - Mānoa (UHM) School of Ocean and Earth Science and Technology.
Finding out the source of the moon's water could help us determine the same thing here on Earth. Earthly water could either be "inherited" from the moon during an ancient impact or was later added by asteroids.
To make their findings the researchers looked at measurements from lunar samples using ion microprobes. They looked at hydrogen and its isotope deuterium ("hydrogen with an extra neutron in its nucleus"), the news release reported. The ration or hydrogen and deuterium can indicate water levels in these samples.
Water was discovered on the moon in 2008, but the samples brought back by the Apollo mission did not contain any water.
"This was consistent with the idea that blossomed during the Origin of the Moon conference in Kona in 1984 -- that the Moon formed by a giant impact with the still-growing Earth, leading to extensive loss of volatile chemicals. Our work is surprising because it shows that lunar formation and accretion were more complex than previously thought," Robinson said.
There are still many rocks left to be studied; the researchers are planning on looking at a new set of Apollo samples in the future.
