Graphene find in China’s Chang’e-5 moon samples challenges lunar origin theory

Discovery has potential to upend scientific consensus that the moon’s formation was the result of a small planet colliding with Earth

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Chinese researchers have discovered a form of carbon in lunar soil samples collected in 2020 which could overturn the theory that the moon was formed by a cosmic collision between Earth and a smaller planet. Photo: Reuters

Published: 12:00pm, 26 Jun 2024Updated: 4:13pm, 26 Jun 2024

Chinese scientists have discovered graphene – a form of pure carbon – in lunar soil samples collected four years ago by the Chang’e-5 mission, a finding that could challenge a prevalent theory of the moon’s origin.

According to the Jilin University-led researchers, the presence of carbon challenges an assumption behind the commonly held view that the moon was formed in a collision between the Earth and another small planet.

“The prevalent giant impact theory has been strongly supported by the notion of [a] carbon-depleted moon derived from the early analysis of Apollo samples,” they said, in an unedited manuscript published online by the National Science Review.

The researchers said that a recent study from Japan had also challenged the giant impact theory by showing the moon had emission fluxes of carbon ions all over it, “suggesting the presence of indigenous carbon”.

To understand the origins of this carbon, the Chinese research team said a study of young lunar samples – just 2 billion years old – could help them to “unravel the crystalline structure of the indigenous carbon” present on the moon.

After analysing the graphene found in the sample, the researchers concluded that the moon may actually have a carbon capturing process on its surface that could explain its presence.