The Moon is more radioactive than you might expect

The Moon is more radioactive than you might expect

Turns out the Moon is pretty inhospitable. Who knew?

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Image credit: Getty

Published: July 28, 2024 at 6:00 am

Recently, using data from the Chinese lunar probes Chang’e-1 and Chang’e-2, scientists found excessive heat below the surface of a suspected volcanic feature on the Moon known as Compton-Belkovich

The existence of such a large hotspot on the lunar surface can only be explained if the underlying granite rock contains elements undergoing radioactive decay, such as thorium and uranium. 


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Researchers estimate that the level of this background radioactivity is about 0.3 millisieverts per year. 

This is actually small compared to the approximately 6 millisieverts per year that every person on Earth receives annually, due to natural sources of radiation.

There are however other sources of radiation that being on the Moon would expose you to, which you are protected from on Earth due to the planet’s magnetic field. These include galactic cosmic rays, energetic particles from the Sun, and neutrons and gamma rays from interactions between radiation and the lunar soil. 

An estimate of the average maximum dose of all these sources of radiation is more than 400 millisieverts per year. This could be much higher following extremely energetic solar flares. 

So, although the Moon has a very low level of natural radioactivity, it’s a harsh environment when considering all sources of ionising radiation. 

This article is an answer to the question (asked by Susan Mcclure, via email) 'Is the Moon radioactive?'

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