Ceres, named after the Roman goddess of agriculture, was discovered in 1801 by Giuseppe Piazzi. It was first called a planet, then demoted to asteroid status, and now is called a dwarf planet. The largest object in the asteroid belt between Mars and Jupiter, Ceres is about 600 miles in diameter--almost one-fourth the size of Earth's moon. It completes one orbit around the Sun in about 4.6 Earth years.
These are Hubble Space telescope images that show Ceres rotating a quarter turn.
Earlier this year NASA canceled, then reinstated, the Dawn mission that is now scheduled to launch in 2007. A probe will be sent on a four-year journey to the minor planet Vesta, where it will spend about a year before being sent to its next target, Ceres, where it will arrive in 2016.
Photo by NASA, ESA, J.Y. Li (University of Maryland) and G. Bacon (STScI)
