Moons Visible on Jupiter
Photograph courtesy NASA/ESA/Erich Karkoschka (University of Arizona)
In this composite image from near-infrared light, two of Jupiter's moons are visible against the planet. The white circle in the middle of Jupiter is Io, and the blue circle at upper right is Ganymede. The three black spots are shadows cast by Io, Ganymede, and another moon, Callisto.