That can't be Ceres.

"Ceres has been known since 1801, but its small size has made it difficult to study. Until recently, it was believed to be a relatively rocky body. But recent observations from Hubble and evidence from the Dawn spacecraft, which just arrived there, have raised an intriguing possibility: that Ceres is less a ball of rock and more a watery dwarf planet with an icy mantle and a slushy ocean below. Located in the asteroid belt between Mars and Jupiter, the world could be our nearest oceanus neighbor. If it's true, it would be the nearest world to Earth with an ocean. ."