Europa is the second of the Galilean satellites and the smallest. Just slightly smaller than our Moon the crust is composed primarily of rock and ice.
The Galileo spacecraft took this spectacular true-color photo after entering into orbit around Jupiter.
Voyager 2 snapped this photo of the crescent Europa moon during its flyby of Jupiter revealing a young surface (sans craters) of most likely ice and dirt.
This picture was taken from a distance of about 2 million kilometers (five times the distance from the Earth to the Moon). The bright areas are probably ice deposits while the darkened areas may be the rocky surface or areas with a more patchy distribution of ice. The most unusual features are the systems of long linear structures which cross the surface in various directions. They may be fractures or faults which have disrupted the surface.
Italian scientist Galileo Galilei has discovered what he calls the Medicean stars (in honor of the Medici family) Jupiter I, II, III and IV orbiting the planet Jupiter when he pointed his telescope to the heavens.
Of course photography did not exist in the 1600's so the picture above is a modern day view through a small telescope that closely represents what Galileo would have seen. Of course Jupiter II we now know as Europa. This discovery led to the demise of the long held theory that the Earth was at the center of the universe and a new understanding that the planets (including the Earth) orbit the Sun.