Jupiter's Dry Spots . ... Credit Copyright: . Credit Galileo Project , JPL , NASA Explanation: Known for its spectacular images of Jupiter's moons, Io , Ganymede , Callisto , and Europa , the robot spacecraft Galileo has also aggressively explored the Jovian atmosphere. ... It is now believed that the probe entered through one of Jupiter's dry spots , similar to the dark region in this image of the swirling Jovian cloud deck . ... NASA Web Site Statements, Warnings, and Disclaimers . ...