sentences:  Models of Saturn's moon Titan density indicate the presence of a subsurface ocean layer.Similar density estimations are strong indicators of an subsurface ocean on Enceladus.Initial analysis of 55 Cancri e's low density indicated that it consisted 30% supercritical fluid which Diana Valencia of the Massachusetts Institute of Technology proposed could be in the form of salty supercritical water, though follow-up analysis of its transit failed to detect traces of either water or hydrogen.