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
Exploration of Jupiter results of the "Galileo" mission include: On December 11, 2013, NASA reported, based on results from the Galileo mission, the detection of "clay-like minerals" (specifically, phyllosilicates), often associated with organic materials, on the icy crust of Europa, moon of Jupiter. The presence of the minerals may have been the result of a collision with an asteroid or comet according to the scientists. NASA launched "Juno" on August 5, 2011 to study Jupiter in detail. It entered a polar orbit of Jupiter on July 5, 2016. The spacecraft is studying the planet's composition, gravity field, magnetic field, and polar magnetosphere. "Juno"