NASA is funding a new study to analyze the cracks on the surface of Charon, Pluto's largest moon, to determine if the planet's core was ever warm.

The space agency announced Friday that the New Horizons spacecraft will pass by the solar system's most remote planet in July 2015 for a closer look. Like Jupiter's moon Europa and Saturn's moon Enceladus, NASA scientists believe Charon could have sub-surface oceans.

The fly-by scheduled for next year will be the closest observation of the planet to date, but a team of scientists has already published a study in the journal Icarus. Pluto orbits our sun at 29 times the distance Earth does.

"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," study lead author Alyssa Rhoden, of NASA's Goddard Space Flight Center in Greenbelt, Md., said in a press release. "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."

With Enceladus and Europa, gravity from other planets cause their orbits to resemble an oval more than a circle. The result is believed to have caused the stress fractures on the moons' surfaces.

Rhoden's study found a similar past of a slightly oval-shaped orbit for Charon, resulting in friction that could have given the moon its fractures and warmed it interior. If warmed enough, Charon could have subsurface oceans like Enceladus and Europa do.

"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," Rhoden said. "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."

However, the team of scientists believe whatever subsurface ocean that could have existed on Charon is now frozen since the moon's orbit is now stable and circular.

"Since it's so easy to get fractures, if we get to Charon and there are none, it puts a very strong constraint on how high the eccentricity could have been and how warm the interior ever could have been," Rhoden said. "This research gives us a head start on the New Horizons arrival - what should we look for and what can we learn from it. We're going to Pluto and Pluto is fascinating, but Charon is also going to be fascinating."