Good news for thirsty lunar explorers: NASA says it has detected water on the sunlit surface of the moon for the first time. Researchers using the Stratospheric Observatory for Infrared Astronomy—a Boeing 747 that makes observations from 45,000 feet—confirmed that the chemical signature of H20 was spotted on the moon's surface in Clavius, one of the largest crater formations, CNET reports. "The detection is very unique for molecular water," says planetary scientist Shuai Li, co-author of a study published Monday in the journal Nature. "It is the same thing as we drink on Earth," says Li. "But the abundance is extremely low. You will need to process a few thousand kilograms of lunar regolith to get 1 kilogram of water."
Lead researcher Casey Honniball says the find raises some intriguing questions. "Without a thick atmosphere, water on the sunlit lunar surface should just be lost to space,” Honniball says in a NASA release. "Yet somehow we’re seeing it. Something is generating the water, and something must be trapping it there." In 2018, NASA detected ice on the moon—but only in "cold traps" in craters at the poles with temperatures as low as -400 degrees Fahrenheit. "They happen to be the coldest known places in the Solar System, believe it or not,” planetary scientist Paul Hayne tells the Verge. But in another Nature study Monday, Hayne and other researchers said they had found evidence of "micro cold traps" across a vast area of the lunar surface, potentially holding water that would be much easier for astronauts to reach. (Read more moon stories.)