Against the background of huge Jupiter its satellites, even the largest, are involuntarily lost. And the radius of these space "kids" reaches from one and a half to two thousand kilometers.
Otherwise satellites of the major planet of the Solar system are called the Moon of Jupiter. The largest satellites of Jupiter opened at the moment are: Io, Callisto, Ganymede and Europe. These space bodies carry to Galilean satellites of Jupiter.
Io – the satellite volcano. Volcanic activity on this celestial body does not stop for a minute. Color of a lava (from light shades to dark brown) depends on the substances which are contained in it: most often it is basalt or sulfur. The surface of the satellite is covered by hundreds of "pockmarks" of volcanoes – acting or already extinct. Diameter of some craters reaches dozens of km. To Io there is an atmosphere. Let in it there is no oxygen, and only gases from volcanic activity, but there is enough magnetic attraction of a metal kernel of the satellite that to hold it. The sizes of Io have about 3600 km a diameter.
Callisto, Europe and Ganymede are known that they on their surface are a layer of the frozen water. On the depth and volume it can be compared to terrestrial oceans. Thanks to the proximity to Jupiter, on Ganymede and Europe there is an atmosphere. As magnetic field of Jupiter has considerable impact on these satellites – on them the weak volcanic activity is revealed. The sizes of Europe are 3121 km in the diameter, and Ganymede in the diameter equals 5262 km. Ganymede is the largest satellite of Jupiter and also the biggest satellite of all Solar system. The weight of this celestial body exceeds the weight of the Moon twice.
Callisto has no atmosphere as is far from Jupiter. Most strongly she suffers from falling of meteorites. Craters from falling of some meteorites reach hundreds of kilometers. The satellite has the sizes of 4820 km in the diameter.