Ceres has never quite decided exactly what is should be when it grows up. Originally declared a planet when it was found in the nineteenth century, it was quickly demoted to being ‘star-like’ – asteroid. But it has always stood out from its fellow asteroid. For a start it, by itself, accounts for 1/3 the mass of the entire asteroid belt. Then when Pluto got demoted, Ceres got promoted to the status of dwarf planet. It is important enough to have it’s own mission, called Dawn. Now the big suppose is how much water it might have.
From The Verge
Scientists have speculated for decades that Ceres — the planet-like heavenly body embedded in our solar system’s asteroid belt — might contain water, still considered a rarity in our solar system. They haven’t been sure, though, until now: researchers at the European Space Agency and the Observatoire de Paris (Paris Observatory) have used the Herschel space telescope to detect two “geysers” on Ceres’ surface, blasting plumes of water vapor into the void. Further analysis indicated that some of the water ends up falling back onto the dwarf planet’s surface.
What’s less clear, though, is where the water is coming from. Scientists involved in the research speculate that an ocean could lie beneath Ceres’ surface, or there could just be isolated zones of liquid fueling each of the geysers. Fortunately, help is on the way: NASA’s Dawn spacecraft arrives at Ceres in February of next year after studying asteroid Vesta, which should provide the high-resolution images researchers need to decode the mysteries of the largest object between Mars and Jupiter.