November 26, 2014

A remastered image of Jupiter’s moon Europa released by NASA shows, for the first time, how this ice-covered body would appear to the human eye. The image is actually a mosaic of images taken by the Galileo spacecraft in the late 1990′s. The previous version of the image had been strongly enhanced with false color. The new image shows Europa in near-natural color.

Areas of Europa’s surface that appear blue or white contain relatively pure water ice. Reddish and brownish areas include higher amounts of other gases or solids. The polar regions, which are visible at the left and right of the image, are much bluer than the more equatorial latitudes. Scientists suspect this difference is due to differences in the size of the ice grains in these locations. (NASA/JPL-Caltech/SETI Institute)

Although Europa is one of the smoothest bodies in the solar system, its surface features include shallow cracks, valleys, ridges, pits, blisters, and icy flows. However, none of them extend more than a few hundred yards or meters upward or downward. In some places, huge sections of the surface have split apart and separated. The surface of Europa has few impact craters (pits caused by collisions with asteroids or comets). The splitting and shifting of the surface and disruptions from below have destroyed most of the old craters.

Europa is considered one of the likeliest places in the solar system for the existence of extraterrestrial life. Beneath its icy surface is an immense lake of salty liquid water that might be a home for living things.