Eleven years ago, a spacecraft changed our view of the moon forever. Data collected by robotic travelers showed that the Earth's only natural satellite was not a dry, dusty desert, as we had long believed. The spacecraft located water samples.
Scientists could not say for sure how much "molecular" water was. Discoveries in 2009 led scientists to suspect that much of the moon's "water" was hydroxyl, because it is more thermally stable than molecular water.
On Monday, two studies published in the journal Nature Astronomy give us even more information.
In the first study, scientists looked at the moon with infrared with great clarity. They determined that it is mainly H2O present on the lunar surface, rather than hydroxyl.
"The results of the research are unique," said Shuai Li, a planetary scientist at the University of Hawaii and co-author of one of the new studies.
Shuai Li has been chasing water on the lunar surface for years and was part of a team scientists who participated in the detection of icy water on the moon in 2018. The ice was trapped in permanently shaded areas of the lunar surface that never receive sunlight. In the second study, another group researchers reported that ice may be even more prevalent and present in other parts of the moon.
Studying water on the moon requires a huge telescope.
One of the keys to the discovery was the Martial Observatory for Infrared Astronomy, or SOFIA, a custom-built Boeing 747 with a telescope mounted on the rear. The aircraft, operated by NASA and the DLR, Germany Aerospace Center, flies about 43.000 feet. During the flight, he opens a door at the back, pointing his telescope at the sky and studying the world with infrared light.
Turning the telescope SOFIA on the moon in 2018, the research team selected two sunny surfaces: one at high latitudes near Clavius Crater and one that was closer to the equator. Around Clavius Crater, the team found water.
"It's the same water we drink on Earth," says Li. "But the abundance is extremely low. You will need to process a few thousand kilos of lunar regolith to get 1 kilo of water. ”