NASA Finds Evidence of Water on Moon’s Sunlit Surface

NASA has just announced that a team of scientists confirmed the existence of water on the sunlit side of the Moon. The confirmation, made using the space agency’s Stratospheric Observatory for Infrared Astronomy (SOFIA), means that—somehow—our lunar companion is trapping H2O on its sunlit surface. And it’s happening despite exceedingly unsuitable conditions. While they have only found trace amounts of water so far, the discovery is wetting appetites for more exploration.

The Guardian reported on the discovery, which puts to rest a long-standing question: Is there actually water on the sunlit portion of the Moon’s surface, or just its close chemical relative, hydroxyl (OH)?

“Prior to the SOFIA observations, we knew there was some kind of hydration [on the Moon’s sunlit surface],” Casey Honniball said in NASA’s press release. Honniball, a Postdoctoral Program Fellow at NASA’s Goddard Space Flight Center who led the team behind the discovery, added “we didn’t know how much, if any, was actually water molecules—like we drink every day—or something more like drain cleaner.”

NASA

Honniball and her colleagues say several factors could be responsible for this water’s existence. One option could be that micrometeorites raining down on the lunar surface carry water and deposit it upon impact. Another is that there is a two-step process occurring: the Sun’s solar winds deliver hydrogen to the Moon’s surface, causing a chemical reaction with oxygen-bearing minerals, creating hydroxyl. Radiation from meteorite bombardment on the Moon’s surface could then be turning that hydroxyl into water.

“Without a thick atmosphere, water on the sunlit lunar surface should just be lost to space,” Honniball told NASA. “Yet somehow we’re seeing it. Something is generating the water, and something must be trapping it there.”

NASA

Despite the certainty of the confirmation, the amount of water that Honniball et al. identified is quite miniscule. Data from the water’s location—Clavius crater near the Moon’s south pole (immediately above)—reveals H2O present at the level of 100 to 412 parts per million. That is approximately equal to a 12-ounce bottle of water in a 1.3-cubic-yard of soil strewn across the Moon’s surface.

Moving forward, Honniball and her colleagues, who published their findings in the journal, Nature Astronomy, will look for water in more sunlit locations on the Moon’s surface; perhaps again with the help of the plane-based SOFIA observatory. This data will help the scientists to understand how this newly confirmed water is produced and stored. And potentially it could even point to the best lunar locales for Moon bases.

Featured Image: NASA