Poor Pluto – no longer considered a planet, and often overlooked even when it was. Cold, tiny and impossibly remote, no one really ever had much to say about Pluto, until now: According to researchers at NASA’s Goddard Space Flight Center, Pluto’s giant moon Charon may have once been warm enough to contain a massive subterranean ocean – which might account for the cracks in Charon’s frozen surface.

“Depending on exactly how Charon’s orbit evolved, particularly if it went through a high-eccentricity phase, there may have been enough heat from tidal deformation to maintain liquid water beneath the surface of Charon for some time,” said Alyssa Rhoden of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Using plausible interior structure models that include an ocean, we found it wouldn’t have taken much eccentricity (less than 0.01) to generate surface fractures like we are seeing on Europa.”

Pluto and its moons, of course, are very difficult to study due to their fringe location. However, in July of 2015, NASA’s New Horizons spacecraft will be the first to visit Pluto and Charon, and will provide the most detailed observations to date.

The eccentricity Rhoden mentions refers to the effect of opposing gravitational pulls have on a moon’s orbit – because they’re locked in a sort of “tug of war” match, orbits tend to be elliptical (eccentric) rather than round. That eccentricity creates strong tides in both surface oceans (Earth) and subsurface ones. In the latter case, the tide fluctuations cause flexion  and tension on the interior of the surface. On a rigid, icy surface like Charon’s, that could lead to cracking.

“Our model predicts different fracture patterns on the surface of Charon depending on the thickness of its surface ice, the structure of the moon’s interior and how easily it deforms, and how its orbit evolved,” said Rhoden. “By comparing the actual New Horizons observations of Charon to the various predictions, we can see what fits best and discover if Charon could have had a subsurface ocean in its past, driven by high eccentricity.”

Though liquid water is an important factor for life, don’t get your hopes up: Charon and places like it (Saturn’s moon Enceladus; Jupiter’s moon Europa) may have once had (or continue to) have liquid water, but life requires much more than that to exist.