There are also cosmic rays. They come from every direction, so even at night. An experiment measured that kind of radiation about 20 years ago https://en.wikip

There are also cosmic rays. They come from every direction, so even at night. An experiment measured that kind of radiation about 20 years ago https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Experiment https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Exp...