Jupiter, Io, and Shadow . ... Credit Copyright: Cassini Imaging Team , Cassini Project , NASA Explanation: Pictured above is the innermost of Jupiter's Galilean satellites , Io, superposed in front of the gas giant planet. To the left of Io is a dark spot that is Io's own shadow. A solar eclipse would be seen from within the shadow spot on Jupiter. Viewed from planet Earth, similar shadows of Jupiter's large moons can often be seen crossing the giant planet's disk. ...