dwarf planet (asteroid belt)
Ceres
The largest object in the asteroid belt and the only dwarf planet in the inner Solar System, explored up close by NASA's Dawn.
- Distance from Earth today
- 326.5 million km2.183 AU · light: 18 min 9 s
- Distance from the Sun today
- 398.0 million km2.661 AU
- As of
- 2 November 2026position from NASA/JPL orbital elements
Where it is today
Top view of the plane of Earth’s orbit, compressed distance scale. Open on the big map with the time slider →
Facts
- Diameter
- 939 km
- Dimensions
- 964.4 × 964.2 × 891.8 km
- Mass
- 938 × 10¹⁸ kg
- Density
- 2,162 kg/m³
- Rotation period
- 9.1 h
- Semi-major axis
- 2.766 AU (413.8 million km)
- Perihelion
- 2.545 AU
- Aphelion
- 2.987 AU
- Orbital period
- 4.60 years
- Orbital eccentricity
- 0.080
- Orbital inclination
- 10.6°
- Albedo
- 0.090
Source of the figures: JPL Small-Body Database (public domain).
Discovery: 1801 – Giuseppe Piazzi
Description
Ceres was the first asteroid ever found, spotted by Giuseppe Piazzi in Palermo on the first night of 1801, and for a while it was counted as a planet. Since 2006 it has been classed as a dwarf planet: it is massive enough to have pulled itself into a nearly round shape. Its surface mixes rock with water ice, clays and salts, suggesting that liquid brine once existed – and may still linger – beneath the crust. NASA's Dawn orbited Ceres from 2015 to 2018 and revealed the bright salt deposits in Occator crater and the lonely mountain Ahuna Mons, thought to be an ice volcano.