Ceres

Ceres (1 Ceres) is the largest asteroid and the first discovered, and now classified as a dwarf planet, being spherical due to its own gravity. It lies in the main asteroid belt, between the orbits of Mars and Jupiter. It was termed a planet when it was first discovered in 1801, but after numerous asteroids were discovered, the convention grew to distinguish asteroids from planets. Characteristics:

• 0.00016 Earth masses (0.0128 Moon masses).
• 470 km radius (0.074 Earth radii or 0.27 Moon radii or roughly 0.4 Pluto radii).
• 4.6 years - orbital period.
• 9 hours - solar day.
• 2.77 AU - orbital radius (semi-major axis).
• 0.0785 - orbital eccentricity.

Ceres has no moons. Ceres has been visited by one space probe, Dawn, which began orbiting it in 2015, observed for three years until contact was lost, and continues to orbit it.