Dwarf planet Ceres is the largest object in the asteroid belt between Mars and Jupiter, and it's the only dwarf planet located in the inner solar system. It was the first member of the asteroid belt to be discovered when Giuseppe Piazzi spotted it in 1801. Ceres probably has a solid core and a mantle made of water ice. In fact, Ceres could be composed of as much as 25 percent water. If that is correct, Ceres has more water than Earth does. Ceres' crust is rocky and dusty with large salt deposits