U.S. As humans prepare to return to the moon in this decade, the biggest risk to astronauts in the future is space radiation that can cause lasting health effects ranging from cataracts to cancer and neurodegenerative diseases.
Although Apollo missions in the 1960s and 1970s proved that it was safe for people to spend a few days on the lunar surface, NASA did not take daily radiation measures that would allow scientists to determine just how long they could last.
The issue was resolved on Friday after a Chinese-German team published in the journal Science progress Results of an experiment conducted by China’s Chang’i4 Lander in 2019.
“The lunar radiation you have on the ISS (International Space Station) is two to three times greater,” Robert Weimer-Swingruber, an astrophysicist at Kill University, told AFP.
“So it limits your stay on the lunar surface to about two months,” he added, “once you’ve been exposed to radiation from a week-long trip there, and a week back, it’s taken into account.”
There are many sources of radiation exposure: galactic cosmic rays, the occurrence of scattered solar particles (for example from solar flares), and neutron and gamma rays from the interaction between space radiation and the lunar surface.
The radiation unit is measured using a sewer, which measures the amount absorbed by human tissues.
The team found that there are 1,369 microseverts per day exposed to radiation on the moon – about 2.6 times the daily volume of the International Space Station crew.
This is because the ISS is still partially shielded by the Earth’s protective magnetic bubble, called the magnetosphere, which ignores most of the radiation from space.
Earth’s atmosphere provides extra protection for humans on the surface, but the higher we go, the more contact we make.
“The level of radiation we have measured on the moon is 200 times higher than the Earth’s surface and five to 10 times higher than the flight from New York to Frankfurt,” added Weimar-Schweingruber.
NASA is planning to bring humans to the moon by 2024 as part of the Artemis mission and said it has plans for a long-term presence that will include astronauts working and life on the surface.
One task for Wimber-Schweingruber is around if we humans should spend more than two or three months: Build radiation-resistant housing by coating a lunar surface of 800 centimeters (inches).
ન્સી Agency France-Press
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