It has been an exciting week for astronomy buffs. A possible second moon, closer look at Jupiter, and more recently sub-surface oceans on Pluto.
A recently published study postulates that changing phases of a sub-surface ocean are responsible for the tectonic activity of the dwarf planet as evinced by New Horizons. The spacecraft found evidence for geological activity on Pluto, including icy volcanoes, for which varying explanations have been suggested. The simplest perhaps, water freezing and melting, could be the answer.
"Thanks to the incredible data returned by New Horizons, we were able to observe tectonic features on Pluto's surface, update our thermal evolution model with new data and infer that Pluto most likely has a subsurface ocean today," said Noah Hammond, a graduate student in Brown's Department of Earth, Environmental and Planetary Sciences, and the study's lead author.
What Hammond and team have suggested is the sub-surface ocean, perhaps frozen partially close to the surface, is responsible for the extensional tectonics including observed faults running as deep as 4 km. A completely frozen ocean, given low temperatures and high pressures in Pluto's vicinity, would have taken the form of ice II, a crystalline form that would contract the dwarf planet.
"We don't see the things on the surface we'd expect if there had been a global contraction," Hammond said. "So we conclude that ice II has not formed, and therefore that the ocean hasn't completely frozen." Pluto's ice shell, comprising of exotic ices including those of nitrogen and methane, perhaps prevent it from losing more heat to space.
The paper suggests an interesting possibility of water oceans on distant cosmic bodies in the far reaches of the solar system. While Hammond and team did not speak of life, which is often mentioned when talk of water surfaces in the space, one cannot help but wonder if some form of life could thrive in such seemingly harsh environments.
