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Water on the moon is more common than scientists thought, with pockets of ice hiding in shadowy regions of “eternal darkness,” some as small as a penny, new studies reveal.
Scientists have been finding signs of water on the moon since 2009 and, in 2018, confirmed the presence of water ice on the lunar surface. Now, researchers in two new studies have not only further confirmed the presence of water on the moon, but also found that the lunar surface could be harboring plentiful patches of secret ice in “cold traps,” regions of permanently shadowed spots on the moon.
“If you can imagine standing on the surface of the moon near one of its poles, you would see shadows all over the place,” study author Paul Hayne, assistant professor in the Laboratory of Atmospheric and Space Physics at CU Boulder, said in a statement. “Many of those tiny shadows could be full of ice.”
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Finding water on the moon
In one of these studies, a team led by Hayne used data from NASA’s Lunar Reconnaissance Orbiter to study the distribution of cold traps, where water could not only exist but be permanently captured, on the moon. They found not only a wide variety of cold traps — with “micro cold traps” as small as 0.39 inches (1 centimeter) in diameter — but there could be hundreds or even thousands of times tinier “micro” cold traps than larger ones. They also found these permanent shadows at both poles.
In fact, Hayne’s team found that a whopping 15,444 square miles (40,000 square kilometers) of the lunar surface has the capacity to hold water. That’s more than twice the area scientists previously earmarked for water ice on the moon.
The interesting nature of these “cold traps,” is that they’re not just cold, shadowy areas where water is more likely to congregate. They are so cold that water, or ice, would be literally trapped there for incredible amounts of time.
“The temperatures are so low in cold traps that ice would behave like a rock,” Hayne said in the same statement. “If water gets in there, it’s not going anywhere for a billion years.”
While Hayne and his team stated that they need to actually find this ice with rovers or crewed missions to fully verify its existence, this new finding could prove monumental in humanity’s plans to not only return astronauts to the moon (NASA hopes to do that by 2024 with its Artemis program), but also to create long-term human encampments on the lunar surface as a proving ground and jumping-off point to Mars.
“If we’re right, water is going to be more accessible for drinking water, for rocket fuel, everything that NASA needs water for,” Hayne said in the same statement. “Astronauts may not need to go into these deep, dark shadows … They could walk around and find one that’s a meter wide and that might be just as likely to harbor ice.”
Solidifying science with SOFIA
In the other study, researchers led by Casey Honniball, a NASA Postdoctoral Program Fellow at NASA Goddard Space Flight Center, studied water on the moon using data from NASA’s SOFIA (the Stratospheric Observatory for Infrared Astronomy) airborne telescope.
Previous work identifying water on the moon was based on a spectral signature (the distinct “barcode” that scientists use to identify materials, which is reflected as a function of wavelength) that didn’t distinctly show whether the target was water or hydroxyl bound to minerals on the lunar surface.
With these new measurements, researchers were able to spot the spectral signature of water without there being the possibility of it being hydroxyl. They found that water is plentiful at high southern latitudes on the moon and exists at around 100 to 400 parts per million. The scientists suggest that this water likely exists “sandwiched” between grains on the lunar surface, which protects it from the environment.
Honniball’s work was published today (Oct. 26) in the journal Nature Astronomy. Hayne’s work was also published today in the same journal.
Email Chelsea Gohd at firstname.lastname@example.org or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.