Ceres

Ceres

Dwarf planet · 2.77 AU from the Sun

Ceres facts

Type
Dwarf planet
Distance from the Sun
2.77 AU (4.14 × 10⁸ km)
Orbital period (year)
4.61 Earth years
Diameter
939 km
Mass
9.38 × 10²⁰ kg
Moons
0
Rotation period (day)
9.1 hours
Axial tilt
Mean temperature
-105 °C
Discovered
1801, by Giuseppe Piazzi

Orbit

Compressed scale; positions shown for 2026. Position is approximate.

About Ceres

Ceres is the largest object in the asteroid belt between Mars and Jupiter and the only dwarf planet in the inner Solar System. Round enough to be pulled into a sphere by its own gravity, it may hold water ice and briny reservoirs beneath its cratered crust.

Ceres: frequently asked questions

What is Ceres?
Ceres is a dwarf planet in our Solar System, orbiting the Sun at an average distance of 2.77 AU (4.14 × 10⁸ km). Ceres is the largest object in the asteroid belt between Mars and Jupiter and the only dwarf planet in the inner Solar System.
How far is Ceres from the Sun?
Ceres orbits the Sun at an average distance of 2.77 AU, about 4.14 × 10⁸ km. One AU is the Earth-Sun distance, so Ceres is roughly 2.8 times Earth's distance from the Sun.
How long is a year on Ceres?
Ceres takes 4.61 Earth years to complete one orbit of the Sun, which is one Ceres year. By Kepler's third law, bodies farther from the Sun take longer to go around.
How many moons does Ceres have?
Ceres has no moons.
How big is Ceres?
Ceres has a diameter of about 939 km and a mass of roughly 9.38 × 10²⁰ kg.
Why is Ceres a dwarf planet and not a planet?
Ceres orbits the Sun and is round, but it has not cleared its orbital neighbourhood of other objects, the third rule the International Astronomical Union set in 2006. Bodies that meet the first two rules but not the third are called dwarf planets.

See Ceres in motion

Open the interactive Solar System orrery →

Data from NASA/JPL and NSSDCA. Source.