New evidence shows a possible ocean on Pluto

Observations by NASA's New Horizons spacecraft - managed from Johns Hopkins University - indicate Pluto may have rolled over on its axis eons ago, the result of tidal forces with jumbo moon Charon, NASA scientists said on Wednesday.

"It's a big elliptical hole in the ground, so the extra weight must be hiding somewhere beneath the surface. And an ocean is a natural way to get that," lead author Francis Nimmo of the University of California, Santa Cruz, said in a statement.

The studies focus on a 600-mile long, 250-mile wide and 2-mile deep basin - known as Sputnik Planitia after the Russian satellite that launched the Space Age in 1957 - in the left lobe of Pluto's heart-shaped region.

Subsurface oceans may also be on other similarly sized worlds orbiting in the Kuiper Belt, a so-called twilight zone on the fringes of our solar system, according to Nimmo. "They may be equally interesting, not just frozen snowballs," he noted.

Despite being about 40 times farther from the sun than Earth, Pluto has enough radioactive heat left over from its formation 4.6 billion years ago to keep water liquid.

jbh/bw (AP, Reuters)