Europa

Europa yoorō´pe , in astronomy, one of the 39 known moons, or natural satellites, of Jupiter . Magnetic-field data collected by the space probe Galileo in 2002 strongly indicates a liquid-water ocean—similar to oceans found on Earth and possibly capable of supporting simple life forms—beneath Europa's frozen surface.

Europa Smallest of Jupiter's Galilean satellites, with a diameter of 3138km (1950mi). Mainly rock, Europa's smooth water-ice crust is criss-crossed by a network of light and dark linear markings. A form of ice tectonics might be operating on the planet, since there are very few craters.

Europa The fourth-largest satellite of Jupiter and the second of the four Galilean satellites from the planet; also known as Jupiter II. Europa orbits in 3.551 days at a distance of 671 100 km. Its period of axial rotation is the same as its orbital period. Its diameter is 3124 km, making it only slightly smaller than our Moon. Europa's density of 3.01 g/lcm³ indicates that it is mainly composed of silicate rock, mixed with at least 5 % water. It has a bright, icy surface of albedo 0.67, dominated by networks of dark, linear cracks, some over 1000 km long. Many of these are curved and are termed flexus; they are thought to arise from tidal stresses. Impact craters on Europa are few and far between, indicating that the surface is young and perhaps being resurfaced by icy flows from below the surface. Indirect evidence suggests the widespread presence of liquid water below the icy crust, but neither the depth nor the extent of this subsurface sea are known.