What are the radiation levels on the moon and Mars?
The radiation levels on the moon and Mars are similar and change with the approximate 11-year variation in the solar cycle. Radiation levels on Mars are probably lower than on the moon’s surface because Mars has a thin atmosphere, composed mainly of carbon dioxide, that acts as a radiation shield. Estimates of radiation levels in deep space for thinly shielded spacecraft resulting from galactic cosmic rays range from ~ 0.3 Sv per year during solar maximum activity to ~ 1 Sv per year during solar minimum periods (L.W. Townsend, F.A. Cucinotta, and J.W. Wilson, “Interplanetary Crew Exposure Estimates for Galactic Cosmic Rays,” Radiation Research 129, 48-52; 1992). A recent study of radiation levels and dose rates for a very large solar particle event is found in J.L. Parsons and L.W. Townsend, “Interplanetary Crew Dose Rates for the August 1972 Solar Particle Event,” Radiation Research 153, 729-733; 2000.
The radiation levels on the moon and Mars are similar and change with the approximate 11-year variation in the solar cycle. At present we are near the maximum solar activity part of the cycle. Radiation levels on Mars are probably lower than on the moon’s surface because Mars has a thin atmosphere, composed mainly of carbon dioxide, that acts as a radiation shield. Estimates of radiation levels in deep space for thinly shielded spacecraft resulting from galactic cosmic rays range from ~ 0.3 Sv per year during solar maximum activity (about now) to ~ 1 Sv per year during solar minimum periods (L.W. Townsend, F.A. Cucinotta, and J.W. Wilson, “Interplanetary Crew Exposure Estimates for Galactic Cosmic Rays,” Radiation Research 129:48-52; 1992). On a planetary surface the mass of the planet provides shielding from about half of the cosmic rays, resulting in estimated exposures that are about half of those given above. Solar particle events (sometimes called flares, which is not correct term