The Pin
May 08 2020, 8:31 pm
Questioning the current models on its formation, the Moon emits its own carbon ions over its entire surface, as revealed by data from the Japanese lunar orbiter Kaguya.
“Our estimates show that indigenous carbon exists across the Moon, supporting the hypothesis of a carbon-containing Moon, where carbon embedded in its formation and / or was transported billions of years ago,” the team argues. researcher, from the University of Osaka, in an article published in Science Advances.
Some areas, such as the great basaltic plains, emit more carbon ions than other regions, such as the highlands. These plains are made from younger material and as such emit more carbon because they have been exposed to space for a shorter period of time, says lead author Shoichiro Yokota. Older regions have been exposed to more space weathering, so they have already lost much of their carbon.
The researchers compared the Moon’s carbon emissions to estimates of carbon supplied by two external sources: the solar wind and collisions with micrometeoroids, and found that they did not match. “The emission is slightly higher than the supply from outer space,” says Yokota, so the team believes the Moon has its own carbon supply.
The finding suggests that it contains volatile carbon, which was embedded when it was formed or acquired billions of years ago. Volatile compounds have low boiling points and are generally present in the crust or atmosphere of planetary bodies, but were thought to be in short supply in the star.
Analysis of the moon rocks brought by astronauts on the Apollo missions had previously suggested that carbon and other volatile elements were only present on the Moon in its past.
This lack of volatiles is crucial to the widespread hypothesis that the moon formed as a result of a giant impact between a young Earth and a body the size of Mars, resulting in high temperatures that would have evaporated the volatiles.
But the discovery that volatile carbon is still present on the Moon suggests that there were milder temperatures when it formed. “We expect some kind of modification of the lunar birth model,” says Yokota, quoted by New Scientist.
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