Meteorites can strike the moon and cause bursts of water to shoot up out of the ground.
That's the main takeaway from a new study announced by NASA that challenges our perceptions of the moon and other rocky orbs out in space.
Micro-meteorites collide with the moon at high velocity and send shock waves reverberating through the luner surface. They only need to penetrate a few inches to stir up deposits of water, and the high energy of the collision converts the molecules into water vapor. The plumes spurt out into space. Most of the molecules dissipate into the very thin atmosphere around the moon, while some settle back into the ground .
The new insight into our closest neighbor in space comes in a study just published in Nature Geoscience by scientists from NASA, Johns Hopkins University, and the University of Maryland-Baltimore County.
The study's lead author was Mehdi Benna, a planetary scientist at NASA's Goddard Space Flight Center. He told CNN the breakthrough "provides a big piece of the puzzle" as to what happens when meteorites collide with other "airless bodies" around our solar system and beyond.
It shows that water isn't just locked in the soil, and, according to Benna, that has implications for how future human or robotic explorers on the moon will be able to use the resources there on the ground.
Scientists thought meteorites could stir up lunar water deposits. Now they know for sure
Benna, who also holds a planetary scientist role at University of Maryland-Baltimore County, said water is widespread "globally" on the moon. But there's much we don't know about its behavior day-to-day.
He led colleagues in combing through data compiled by the Neutral Mass Spectrometer aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE), a robotic mission that orbited the moon.
Previous lunar probes like Cassini and Deep Impact had shown "the existence of an active water cycle on the moon," Benna and his co-authors wrote. They decided to study 33 water plumes on the surface, 29 of which were known and four which were new.
Scientists knew that the water plumes corresponded to times when meteorite streams were present. And computer molecules had predicted that meteorites could trigger these water plumes.
But Benna's team was able to actually see something that hadn't been confirmed before. This is "the first time it's been observed in practice," he said.
And because scientists confirmed it on one airless body, they can now infer the same process happens everywhere, Benna said.
Though water is widespread in the lunar soil, is spread very thin. The moon is quite dry. One metric ton of regolith (the layer of loose soil and deposits covering solid rock on the lunar source) yields just 16 oz. of water, the amount in an average bottle of water.
The study shows the moon isn't so quiet and desolate
In showing that the moon is simply a static orb, studies like this give us a new portrait of the moon as a rocky world alive with dynamic geological and chemical processes.
Benna said he remembered looking up at the moon as a boy, and thinking of the distant, ancient orb as "quiet and desolate."
But this study tells him, and a millions of boys and girls, a different story.
"What gets me excited," Benna said, is that the study shows the moon changes, reacting to its celestial neighborhood not in manner of decades or centuries, but "over days and even hours."
"Looks are deceiving," Benna said. "The moon is active."