The largest object in the asteroid belt isn’t like its neighbors. It contains a lot more frozen water, along with minerals that formed in a wet environment. Its crust may cover a deep layer of ice with pockets of salty liquid water. And some deep craters near its poles hold big slabs of ice that might have formed fairly recently.
Ceres is about 600 miles in diameter. It’s classified as a dwarf planet – the only one in the inner solar system. It’s in the middle of the asteroid belt, between the orbits of Mars and Jupiter.
But its composition suggests it wasn’t born there. Instead, it might have been born much farther from the Sun, between Jupiter and Saturn. Those giant worlds moved around when the solar system was young, pushing smaller objects into new orbits – possibly including Ceres.
A spacecraft studied Ceres from orbit for more than three years. It found patches of ice inside craters that never see the Sun. A recent study said those patches could be quite young.
The study looked at how Ceres is tilted on its axis, and how the tilt changes. Researchers found that the tilt has been at the correct angle to keep sunlight out of the craters for as little as 6,000 years. Another body might have slammed into Ceres, blasting out some of its water and forming a thin atmosphere. Some of the water then froze inside the craters – creating some chilly deposits on the largest body in the asteroid belt.
Script by Damond Benningfield