Outside low Earth orbit, as experienced by the Apollo astronauts who traveled to the Moon, this background radiation is much more intense, and represents a considerable obstacle to potential future long term human exploration of the moon or Mars.
在地球的低軌道之外，像是前往月球旅行的阿波羅太空人，會遇到更強的背景輻射，並且這也是未來人類要長期探索月球或火星的一大障礙。