Deja Lu...nar? Why Does Water on the Moon Sound Familiar?
NASA kept the scientific community on the edge of its collective seat regarding “exciting news” about the Moon and speculation filled the Twitterverse for a week. But the big reveal may have left you with a sense of deja vu.
NASA’s Monday announcement touted confirmation “that molecular water has been discovered on the sunlit surface of the Moon,” indicating that it “may be distributed across the lunar surface, and not limited to cold, shadowed places.’”
However, this detection of surface water follows more than a decade of discovery about lunar water by the late EPL geochemist Erik Hauri, who first reported the existence of water on the Moon in 2008.
Scientists used to think that the Moon was “bone dry”— depleted of water by the violent events of its formation. Then in 2008, Hauri and his colleagues revealed that tiny beads of lunar volcanic glass collected during the Apollo missions contained water. Three years later, he led the team that discovered water in the Moon’s interior at concentrations not dissimilar to the dryer portions of Earth’s interior.
Unlike Hauri’s investigations, which suggested that water in the lunar interior played an important role in the origin and evolution of the Moon, this new finding indicates that there may be some mechanism actively forming and retaining water on the surface today. According to the NASA press release, it’s likely that this water was delivered by projectiles landing on its surface or could be created by micrometeorite impacts converting the Moon’s OH, ultimately derived from hydrogen implanted by Solar wind, into H2O.
SOFIA for Science
This research relied on data collected from SOFIA, a flying infrared observatory that allows scientists to get above our infrared-blocking atmosphere. This was the first time the project turned its sites on the Moon. Carnegie astrophysicist Alycia Weinberger sits on the SOFIA Science Council that gives advice on the telescope’s scientific mission.
Earlier this year the SOFIA program found itself targeted by NASA budget cuts, but Weinberger thinks there is still a lot of meaningful and important work that can be done with the unique telescope. Weinberger commented, “The Earth's atmosphere is full of water, so observations aiming to find water on the Moon or in other celestial locations are very hard to do from the ground. Near-space observatories like SOFIA have an important role to play in observing the universe at wavelengths normally hidden from us on Earth.”
For more information about this recent discovery, read the NASA press release.