Researchers have detected jets of water vapor being released by the lunar surface during space fragment impacts.
Meteoroid impacts on the lunar surface release water vapor across the Moon, reveals a new study published in the journal Nature Geoscience.
When the Apollo missions brought moon rocks to Earth, scientists found no evidence of water, but over the past decade, data from missions such as Cassini, Deep Impact and Lunar Prospector, and India\’s Chandrayaan-1 have revealed traces of water on Earth. surface of the Moon, and not just at the poles, as expected.
Now, researchers have analyzed data from NASA\’s Earth and Lunar Atmosphere and Dust Environment Explorer (LADEE) mission, which orbited the Moon between October 2013 and April 2014. What did they find? Evidence of small jets of water vapor released at the surface after a meteorite strikes. This water vapor spreads through the thin lunar atmosphere and part is lost in space.
These meteoroid impacts, and therefore the release of water, coincided with 29 known debris wakes that passed close to the Earth and Moon, including the debris clouds that give rise to the Leonid, Quadrantid and Geminid meteor showers.
To release water, meteoroids must penetrate at least about 8 centimeters, and for that, they must be at least 1 inch in diameter. Credits: NASA / Goddard / Dan Gallagher
By analyzing the amount of water released by the impacts of meteorites of different sizes, the researchers estimated that the top 8 centimeters of the lunar soil is dehydrated. Below this thin layer, water comprises about 0.05% of the rock\’s weight, down to about 3 meters deep.
“With our measurements, we were able to see exactly the water leaving the Moon very dynamically by micro-meteoroid impacts, and by analyzing the data, we saw how much water was stored in the lunar reservoir and where it was going,” said Mehdi Benna, scientist. planetarium at NASA\’s Goddard Space Flight Center.
The researchers estimated that meteoroid impacts cause the Moon to lose up to 220 tons of water a year. To sustain this amount of loss over time, they suggested that this water was either present when the Moon formed, about 4.5 billion years ago, or that it was delivered by water-laden space rocks that collided with the Moon. in the course of time.
Lunar samples from the Apollo missions could have been devoid of water because it was likely not embedded in the rocks, but merely covered them subtly. Therefore, the water did not remain in them during the return trips. Future research must also examine how this water spreads across the Moon.