Pluto's secrets are being unraveled! Astronomers have found convincing evidence of a massive ocean of liquid water hidden beneath the dwarf planet's icy surface. This exciting discovery ...

This cutaway image of Pluto shows a section through the area of Sputnik Planitia, with dark blue representing a subsurface ocean and light blue for the frozen crust. Disclaimer: AAAS and EurekAlert!

The heat might be coming from a hidden ocean or radioactive elements beneath Pluto's surface. This would be a real turn-up for the books as, until now, astronomers thought Pluto was too old to ...