Astronomers studied the emission from a bow-shock pulsar wind nebula
Illustration of carbon ions emitted from the Moon. (S. Yokota)
SPACE
Carbon Emissions Detected From The Moon Could Force a Major Rethink of Lunar Origins
MICHELLE STARR7 MAY 2020
A spacecraft orbiting the Moon has detected something really peculiar. Our satellite is emitting a steady stream of carbon ions from almost its entire surface, contrary to the long-standing thinking that the Moon is depleted of carbon and other volatile elements.
In fact, it seems that carbon has been there since the Moon's formation, or very shortly after, 4.5 billion years or so ago. This means that the details of the impact theory of the Moon's formation - which largely relies on a lack of volatiles - may need to be reconsidered.
The results come from the Japanese Aerospace Exploration Agency's (JAXA) Selenological and Engineering Explorer spacecraft, better known by its nickname, Kaguya. A decade ago, it spent roughly a year and a half in orbit around the Moon, collecting global-mapping observations.
One of its instruments was an ion mass spectrometer, which detected and mapped lunar ions, including carbon - something that had not turned up in Apollo data, leading to the belief that the Moon had very little of them.
More:
https://www.sciencealert.com/the-moon-is-emitting-carbon-putting-our-formation-theory-to-question