Jupiterís moon Europa under stress

Jupiterís moon Europa under stress

Fig. 9.20 . This mosaic of the Conamara Chaos region on Europa indicates relatively recent resurfacing of the moon. Many sets of parallel and crosscutting ridges and fractures are detected. They are the frozen remnants of surface tension and compression, probably produced by heating and upwelling from below. The break up and movement of the existing crust have formed irregularly shaped blocks of water ice. The blocks have been shifted, rotated, and even tipped and partially submerged within some lubricating material at the time of disruption, most likely soft ice or liquid water, or an ice and water slush below the surface. Some of the blocks have acted like rafts, separating and moving into new positions, somewhat like pack ice in the Earthís polar seas. The presence of young fractures cutting though this region indicates that the surface froze again after the resurfacing, forming solid, brittle ice. This image was taken form the Galileo spacecraft in February 1997. (Courtesy of NASA/JPL.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University