Broken ice on Jupiterís moon Europa

Broken ice on Jupiterís moon Europa

Fig. 9.18 . This enhanced-color image shows subtle differences in the materials that cover the icy surface of Europa. Reddish linear crack-like features (top right) extend for thousands of kilometers. They are caused by the tides raised in Europa by the gravitational pull of Jupiter. As the moon travels along its eccentric orbit the tides vary and fracture the thin, icy crust. The fractures probably open and become filled with a dirty slush from a possible ocean below. Mottled, reddish "chaotic terrain" exists where the surface has been disrupted and ice blocks have moved around. The red material at the fractures and chaotic terrain is a non-ice contaminant and could be salts brought up from a possible ocean beneath Europaís frozen surface. Also visible are a few circular features, which are small impact craters. Europaís surface has very few craters, indicating that recent or current geologic activity has removed the traces of older impacts. The paucity of craters, coupled with other evidence such as the red material, has led astronomers to propose that there might be an ocean of liquid water beneath Europaís surface. This view combines images from the Galileo spacecraft taken in violet, green and near-infrared wavelengths in 1995 and 1998. (Courtesy of NASA/JPL/U. Arizona.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University