Exploration of Jupiter disadvantages for colonization because of the severe radiation conditions prevailing in Jupiter's magnetosphere and the planet's particularly deep gravitational well. Jupiter would deliver about 36 Sv (3600 rem) per day to unshielded colonists at Io and about 5.4 Sv (540 rems) per day to unshielded colonists at Europa, which is a decisive aspect due to the fact that already an exposure to about 0.75 Sv over a period of a few days is enough to cause radiation poisoning, and about 5 Sv over a few days is fatal. Ganymede is the Solar System's largest moon and the Solar System's only
Climate of Mars 5–10 times higher velocities than Earth grains do. A large doughnut shaped cloud appears in North polar region of Mars around the same time every Martian year and of about the same size. It forms in the morning and dissipates by the Martian afternoon. The outer diameter of the cloud is roughly , and the inner hole or eye is across. The cloud is thought to be composed of water-ice, so it is white in color, unlike the more common dust storms. It looks like a cyclonic storm, similar to a hurricane, but it does not rotate. The cloud appears