This "family portrait" is a composite of the Jovian system: the edge of Jupiter with its Great Red Spot + Jupiter's 4 largest moons, known as the Galilean satellites. The moons (top-to-bottom): Io, Europa, Ganymede and Callisto.
Callisto - Fourth moon of Jupiter after Io - Europa - Ganymede. Formed of rock and ices Third largest moon in our solar system after Titan (Saturn) and Ganymede (Jupiter) respectively. Jupiter's Io being fourth and our Luna fifth.
Jupiter Moons - Callisto discovered by Galileo Galilei in 1610 using a telescope. It is thought to have oceans of liquid water beneath its crust. about the size of Mercury, is the largest moon in the solar system. It is more heavily cratered than any
PHOTOS: Spectacular Views Of The Solar System's Moons
This view of Jupiter’s moon Io was captured by NASA’s Galileo spacecraft. Slightly larger than Earth’s moon, Io is the most volcanically active body in the solar system. Credit: NASA/JPL/University of.
Michael Benson’s Awe-Inspiring Views of the Solar System
NASA’s Hubble Space Telescope has the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter’s largest moon. The subterranean ocean is thought to have more water than all the water on Earth& surface.