A sudden discovery: the radiation level on the Moon was 200 times higher than on Earth.
3 days ago, Alexander Martynenko,2
Luna
Formally, the Americans were the first to bring dosimeters to the Moon as part of Project Apollo missions. But the measurement data were not shared with the rest of the world, so it is officially believed that the level of radiation on a natural Earth satellite was the first to measure the Chinese apparatus Chang'e-4 in January 2019. According to a publication in the journal Science Advances, it was 1369 microsieverts per day.
Direct recalculation, including hours and days, shows that the natural radiation level on the Moon is about 200 times higher than the accepted safe standard for the Earth of 0.5 microsieverts per hour. This exceeds the psychological mark of 1 millisievert per day, which means that in a thousand days a person will receive more than 1 sievert of radiation, and this is a guaranteed radiation sickness and death from its consequences. Fortunately, today, space missions last much less.
However, as early as 2024, an American astronaut, certainly a woman, should land on the moon as part of the Artemis program. She will not be alone, the whole team will spend at least a week there, and the list of tasks includes several long-range passages. This will be a real test for the anti-radiation protection system, which will be provided to the astronauts in NASA, because Chang'e 4 found out that the moon has its own radiation source. This is the result of interaction between cosmic radiation and regolith, in addition to solar wind, galactic cosmic rays, etc.
The probable mission to Mars poses even more problems, as it is guaranteed that a person will spend more than a year in space there. And even if he can go back later, it will double the amount of radiation received. Even with the best forecasts, a deeply ill person with acute radiation sickness will return. Therefore, the development of effective anti-radiation protection means is task #1 for future space missions.