Life Without Photosynthesis

Abstract
Recent planetary exploration has provided evidence for large subsurface oceans on several jovian moons. In their Perspective, [Chyba and Hand][1] assess the chances for life in these oceans, which are deprived of sunlight. Photosynthesis is therefore ruled out, but other sources may provide molecular oxygen in sufficiently high concentration to serve as an energy source for life. [1]: http://www.sciencemag.org/cgi/content/full/292/5524/2026