Mars's thin atmosphere does provide significant levels of radiation shielding, such that surface radiation levels are comparable to those in low-Earth orbit: h

Mars's thin atmosphere does provide significant levels of radiation shielding, such that surface radiation levels are comparable to those in low-Earth orbit: http://www.space.com/18504-mars-rover-curiosity-astronaut-radiation.html http://www.space.com/18504-mars-rover-curiosity-astronaut-ra... The Moon, on the other hand, is baldly exposed: https://science.nasa.gov/science-news/science-at-nasa/2005/08sep_radioactivemoon https://science.nasa.gov/science-news/science-at-nasa/2005/0...