NASA discovered water molecules on a sunlit portion of the moon’s surface, the agency announced Monday.
Revealed with the help of the Stratospheric Observatory for Infrared Astronomy (SOFIA) flying observatory, this discovery shows that water may exist throughout the moon’s surface, not just frozen in the coldest, darkest craters on the moon as was previously expected. The full study published in Nature Monday, led by Casey Honniball at the University of Hawaii at Mānoa, revealed an amount of water measuring roughly equal to a 12-ounce bottle of water in a cubic meter of lunar soil located on the surface of the Calvius Crater, but it’s possible that there’s more water under the surface. This water discovery could be beneficial to future missions to the moon and beyond, researchers said in a live call and discussion of the discovery.
The moon’s surface is harsh. It has very little atmosphere to speak of and can reach temperatures of 260 degrees Fahrenheit in sunlight. The presence of water in an area like this is surprising because water would normally vaporize at that temperature on Earth and at an even lower temperature on the moon. Ice in dark, freezing areas of the moon has been observed previously, but these pockets would be difficult to reach in their high-walled craters and harder to extract than water that might be present in soil.
In the call, Honniball noted that the new data does not show enough water to support life on the moon, but it’s possible that there’s enough water present throughout the moon to aid in missions to the moon and NASA’s moon-focused Artemis program, a step on the path to establish a moon to Mars exploration program.
Jacob Bleacher, chief exploration scientist for NASA’s Human Exploration and Operations Mission Directorate, explained in the live discussion that water on the moon could mean missions to the moon wouldn’t need to pack as much water for the journey, opening up weight and space for other payloads. If this water is usable and accessible, it could be used for drinking, converted into oxygen, or used as fuel, he said.
How is there water on the moon?
The presence of water in sunlit areas of the moon is intriguing for two reasons. The first is how it got there, and the second is how it’s staying there.
There are a couple of ideas around how it got there. One is that micrometeorites containing water molecules are hitting the moon’s surface and depositing those molecules. Another is that solar winds carrying hydrogen molecules to the moon could be reacting with oxygen atoms found in some minerals, combining to form hydroxyl (OH), which is then converted into water in the radiation from hot micrometeorite impacts.
As for how the water is staying on the moon, those micrometeorites could be encasing it in little glass-like beads formed out of soil when they make impact. Alternatively, water could be hanging out in the lunar ground, just like here on Earth, protected from the hot sun by grains of surrounding soil.
The water was detected in a pass by SOFIA, which is an airplane fitted with a sizable telescope that flies high up in the stratosphere to pick up unobstructed views of areas outside Earth. It was able to precisely observe wavelengths of water molecules with an infrared spectrometer, Honniball explained in the call.
With further observations and the next moon rover planning to take samples and create a water map of the moon, a better picture of the moon’s water situation will unravel.
