We now know exactly how much radiation astronauts will face on the moon

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fairly difficult
It's likely not enough to be a showstopper for crewed lunar exploration.
An artist's depiction of astronauts walking on the moon as part of NASA's Artemis program.

We finally know what kind of radiation environment future moonwalkers will be stepping into.

Astronauts hopping about on the lunar surface will soak up about 60 microsieverts of radiation per hour, a new study reports. That's 5 to 10 times higher than the rate experienced on a trans-Atlantic passenger flight and about 200 times what we get on Earth's surface, study team members said.

"In other words, a long-term stay on the moon will expose astronauts' bodies to high doses of radiation," co-author Thomas Berger, a radiation physicist at the German Aerospace Center's Institute of Aerospace Medicine in Cologne, said in a statement .

Those numbers are indeed high — but likely not high enough to impede crewed lunar exploration, as we shall see.

Related: The space radiation threat to astronauts explained (infographic)

A pioneering result from a pioneering lander

Scientists have long known that radiation levels are relatively high on the moon, which does not have a thick atmosphere or a magnetic field to protect it. (Our Earth, fortunately, possesses both types of shielding.) But precise numbers have proven elusive.

For example, the dosimeters that NASA's Apollo astronauts took to the moon from 1969 through 1972 recorded the cumulative, total-mission exposure, not a detailed breakdown of radiation levels on the lunar surface. The new study gives us that detailed breakdown.

The numbers come courtesy of the Lunar Lander Neutron and Dosimetry instrument (LND), a German-built experiment that rides on China's Chang'e 4 moon mission . Chang'e 4 made history in January 2019 by performing the first-ever soft touchdown on the moon's largely unexplored far side.

Chang'e 4 consists of a rover named Yutu-2 ("Jade Rabbit 2") and a lander, both of which are still going strong. LND is part of the lander's scientific payload, and its partially shielded position provides "a…
Mike Wall
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