Lunar History Surfaces from Water Discovered in Moon Rocks

Scientists recently discovered water in Moon rocks, and through chemical analysis they found that the amount of water in the Moon's rocky interior actually varies regionally - revealing clues about how water originated and was redistributed on the lunar surface.

That's not to say there's liquid on the Moon, but rather water trapped in volcanic glasses or chemically bound in mineral grains inside lunar rocks. Yet some of these rocks - those originating in the lunar interior - contain much more water than rocks found in other places. In addition, the hydrogen isotopic composition of this lunar water varies from region to region.

Understanding where lunar water originated from may even help scientists uncover the source of water on Earth. There are currently two theories: either, the Moon inherited water from the Earth during the Moon-forming impact, or it was added to the Moon later by comets or asteroids. It might also be a combination of these two processes.

"Basically, whatever happened to the Moon also happened to the Earth," 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, said in a press release.

To better understand this lunar history, researchers compiled water measurements from lunar samples. Specifically, they measured hydrogen and its isotope, deuterium with ion microprobes. The findings brought some new clues about the water to the surface.

"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," Robinson said. "Our work is surprising because it shows that lunar formation and accretion were more complex than previously thought."

Researchers plan to study a new set of Apollo samples from NASA, hopefully uncovering additional clues about the early life of Earth and the Moon.