Europa, Enceladus, and Titan as possible sites for life

Despite quite distinct bulk properties, Europa, the third largest Jovian satellite (d=3138 km), and the Saturnian satellites Enceladus (d∼500 km) and Titan (d=5151 km) share a remarkable common feature which is a strong indication of the presence of liquid water at some level below the surface. The possibilities for the development of life organisms on these bodies are reviewed.