Gibbous Europa . ... Credit Copyright: Galileo Project , JPL , NASA ; reprocessed by Ted Stryk Explanation: Although the phase of this moon might appear familiar, the moon itself might not. In fact, this gibbous phase shows part of Jupiter 's moon Europa . The robot spacecraft Galileo captured this image mosaic during its mission orbiting Jupiter from 1995 - 2003. Visible are plains of bright ice , cracks that run to the horizon, and dark patches that likely contain both ice and dirt. ...