Enceladus: Enceladus has shown geysers of water that were confirmed by the Cassini spacecraft in 2005. Gravimetric data obtained from 2010 to 2011 confirmed the existence of a subsurface ocean. Even though originally it was thought to be localized, most likely in a region of the icy moon's southern hemisphere, evidence collected in 2015 indicates the subsurface ocean is actually global. Furthermore, in additon to water, these geysers from vents located near the south pole of Enceladus contain tiny quantities of salt, nitrogen, carbon dioxide, and volatile hydrocarbons. Tidal flux from Saturn is apparently responsible for the melting of the ocean water, as well as the geysers.
When the American astronomer James Christy discovered Pluto's largest moon Charon back in 1978, astronomers were quick to calculate the mass of the system. Pluto's mass was hundreds of times smaller than the mass originally estimated for it when it was first discovered in 1930. With Charon's discovery, astronomers suddenly acquired a new understanding that something was fundamentally different about Pluto.
Dr. Soderblom and his team, including Dr. Maria Zuber, who is the E.A. Griswold Professor of Geophysics and MIT's vice president of research, have published their findings in the September 10, 2015 issue of the journal Geophysical Research Letters.