Ceres is a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter. It was the first known asteroid, discovered on 1 January 1801 by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily, and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planet, the only one inside Neptune's orbit.
Ceres as imaged by Dawn, May 2015. Two bright spots dot its surface; the bright crater at right is Hualani, while the bright spot at left is the floor of the crater Oxo
Ceres (bottom left), the Moon and Earth, shown to scale
Relative mean diameters of the four largest minor planets in the asteroid belt (dwarf planet Ceres at left)
Ceres, polar regions (November 2015): North (left); south (right). The south pole is in shadow. "Ysolo Mons" has since been renamed "Yamor Mons."
A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be gravitationally rounded, but insufficient to achieve orbital dominance like the eight classical planets of the Solar System. The prototypical dwarf planet is Pluto, which for decades was regarded as a planet before the "dwarf" concept was adopted in 2006.
Ceres (1801)
Pluto (1930)
Quaoar (2002)
Sedna (2003)
