alt Hacker News> Our protection from cosmic radiation is mostly due to Earth's thick atmosphere, not its magnetic field
Primary defense against cosmic radiation: magnetic field
Secondary defense: atmosphere
https://science.nasa.gov/science-research/earth-science/eart...
Yeah, that's nonsense. The radiation in low Earth orbit is only a bit less than above the magnetosphere, and most of that difference is from shadowing by the Earth itself. In contrast, there's a massive decrease in radiation from LEO to to sea level.
Radiation at ISS: 144 mSv per year
Radiation on a trip to Mars: ~340 mSv per year
Cosmic radiation at sea level: about 0.4 mSv per year
The atmosphere is doing the heavy lifting in shielding us from cosmic radiation, not the magnetosphere.