NASA's SOFIA telescope discovers more water in Moon’s Southern Hemisphere

Researchers using NASA's Stratospheric Observatory for Infrared Astronomy (SOFIA) have discovered more water on the sunlit surface of the Moon. The new observations also confirm the 2020 discovery of water in the Moon's southern hemisphere by the telescope.

Led by Casey Honniball, a postdoctoral fellow at NASA's Goddard Space Flight Center in Greenbelt, Maryland, detected molecular water in the Moretus Crater region, located near the Moon's Clavius Crater, one of the largest craters visible from Earth where the original finding took place.

"If you can find [sufficiently] large concentrations of water on the surface of the Moon - and learn how it’s being stored and what form it's in - you can learn how to extract it and use it for breathable oxygen or rocket fuel for a more sustainable presence," said Honniball.

How’s this for a #NASAMoonSnap? SOFIA once again found water in the Moon’s southern hemisphere, creating a map of water abundances in the Moretus Crater. If you look carefully, you can make out lunar features in the map! More: https://t.co/dK2vQyUkbS pic.twitter.com/QL9JSiXo7N

— SOFIAtelescope (@SOFIAtelescope) August 26, 2022

SOFIA, a modified Boeing 747SP aircraft, allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Using its Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST), the flying observatory can look at 6.1-micron emission features from the Moon, a wavelength of emission unique to water.

When looking at the Moon, it is difficult to differentiate between water and hydroxyl, however, SOFIA can easily distinguish between the two. Using the telescope, the astronomers found evidence for a theory about how water came to be on the Moon in the first place, ruling out several previous hypotheses.

"The Moon is constantly being bombarded by solar wind, which is delivering hydrogen to the lunar surface. This hydrogen interacts with oxygen on the lunar surface to create hydroxyl," Honniball said. Thereafter, when the lunar surface is hit by micrometeorites, the high temperature of the impact causes two hydroxyl molecules to combine, leaving behind a water molecule and an extra oxygen atom.

According to the researchers, a lot of this water is likely lost to space, while some is trapped within glass formed on the Moon's surface by the bombardment.

NASA's upcoming Volatiles Investigating Polar Exploration Rover (VIPER) mission will map water in different forms and other volatiles. The lunar rover will arrive on the South Pole of the Moon in late 2024.