The moon is not haunted. Sorry, there aren’t any aliens up there. Fortunately, unlike the fake Election Day asteroid, it will not collide with Earth. When NASA announced that it would share a “exciting new discovery about the moon”, it spurred lots of fun speculation, but now we know the truth. And it’s certainly as exciting as some of those theories promised.
Scientists have announced that they discovered signs of molecular water on the moon’s sunlit surface. The discovery has the potential to forever change our connection with our nearest cosmic neighbor. “This is exciting because the expectation is that any water present on the sunlit surface of the moon might not survive the lunar day,” Paul Hertz, the Astrophysics division director at NASA Headquarters, said in a press conference Monday. Because the moon lacks an atmosphere, any water on its exposed surface was assumed to be lost to space.
“[I]f we find a large concentration of water on the sunlit moon, we may be able to extract it and use it as a resource for exploration,” Casey Honniball, a Postdoctoral Program Fellow at NASA’s Goddard Space Flight Center, tells Popular Mechanics via email.
Since 2009, when a NASA instrument aboard India’s Chandrayaan lunar orbiter discovered water ice in the moon’s permanently shadowed polar craters, scientists, engineers, and space policy wonks have been diligently working to develop plans to use the resource on future missions. Lunar water could be used to quench the thirst of parched astronauts. It might also be broken down to provide breathing oxygen or propellant for rocket launches throughout the solar system. There’s still a lot that researchers must learn about these water deposits.
Honniball and her colleagues conducted the observations using NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) airborne telescope. The modified Boeing 747P flying laboratory is equipped with a 9-foot reflecting telescope that examines the stars in infrared. The Earth’s atmosphere affects observations made by ground-based telescopes. SOFIA can cut through the blur to deliver sharper views of the cosmos by rising to an altitude of up to 44,000 feet.
According to their paper, which was published in the journal Nature Astronomy, the scientists investigated Clavius crater, the second largest visible crater on the near side of the moon, for deposits of molecular water. The crater is located in the moon’s southern hemisphere at a high latitude. It was the perfect spot to look for water, Honniball says.
Ultimately, the team found traces of water—an amount roughly the equivalent of a 12-ounce glass of water for every cubic meter of regolith—trapped in small glass beads in the lunar soil. Water molecules may have caught a ride on comets and become trapped inside the glass beads as the comets collided with the moon’s surface, according to researchers. Solar wind can also generate lunar water, which carries hydrogen ions, reacts with oxygen atoms on the lunar surface.
The findings could also shed light on “past and current processes occurring on the moon,” Honniball, the paper’s lead author, explains. For example, learning more about where the water originated from, as well as how it moves and is kept on the surface, could help us better understand how physical processes work in our environment. It could also reveal mysteries about the sun’s evolution, our solar system, and the relationship between both.
Honnibal says more observations of the lunar surface are needed—especially at different times of the lunar day. She describes her findings as “a snapshot of the lunar water cycle.” Additional SOFIA missions are planned to explore various sections of the moon at various periods, including during different lunar phases. There are now more questions than answers.
Luckily, NASA plans to send its Volatiles Investigating Polar Exploration Rover (VIPER) to the lunar surface in 2022. The rover, however, is planned to examine craters in the moon’s south pole’s shadowed regions rather than any of its bright regions. And space agencies all over the world are competing to return astronauts to the moon. NASA’s highly publicized Artemis mission aims to return boots to the lunar surface by 2024. Meanwhile, China’s space agency intends to construct a permanent settlement on the moon by the 2030s.
“We know that there’s water at the moon, but we don’t know exactly how accessible that lunar water is for our future explorers,” Jacob Bleacher, the chief exploration scientist for the Human Exploration and Operations Mission Directorate at NASA Headquarters, said during the press conference. “Knowing where we can find water is a good first step, but we need to know more about the water to understand if and how we can use it for both science and exploration.”