The new research paper is published in Geophysical Research Letters. The researchers said that they come to this conclusion after going through the data by NASA's New Horizons spacecraft, which did not show contraction in the surface.
Lead researcher Noah Hammond from Brown University said that he come up with the findings after assessing the data from the New Horizons mission. The researchers used the evaluation to develop a thermal computer model of Pluto's evolution. Tectonic activity on the surface of Pluto did not show contraction in the surface.
Hammond mentioned, "What New Horizons showed was that there are extensional tectonic features, which indicate that Pluto underwent a period of global expansion. There is a possibility that a subsurface ocean that was gradually freezing would have caused this kind of expansion."
The researchers also canceled presence of Ice II formation. It is notable that Enceladus, a moon of Saturn, is an ocean world, having warm water under the ice shell. The probability of finding life on Enceladus might be higher. The new study, however, suggested that liquid water on Pluto is more than what was believed before.
According to a story published on the topic by IB Times, "NASA's historic New Horizons flyby of Pluto on July 14, 2015, lasted only for a brief moment, but that was more than enough time to retrieve data that will take scientists decades to unpack. With each photo or data release, Pluto brings more new surprises as a dwarf planet that defies expectations. Underneath its icy shell could be a liquid ocean, according to research published Tuesday."