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Dawn Spacecraft image of Ceres
Credit: NASA

Ceres is a dwarf planet that orbits within the asteroid belt.

It is made of the mainly ice and rocky minerals and by itself makes up a third of the mass of the whole asteroid belt! It is 930 kilometres (580 miles) across, about half the size of our own Moon.

Ceres was discovered way back in 1801 by the Italian astronomer Giuseppe Piazzi, and it remains the only dwarf planet in the inner Solar System, where it takes 4.6 years to orbit the Sun.

The NASA spacecraft, Dawn, began orbiting the dwarf planet in March 2015 and is continuing to send back a huge amount of data, finding out a lot about the dwarf previously unknown - for example the surface seems to have icy volcanoes on it!

Dwarf Planet Data Sheet show »« hide
Facts and FiguresCeresPlutoHaumeaMakemakeEris
Orbital distance (AU)12.7739.543.145.867.7
Orbital Inclination10.6°17.1°28.2°29°44°
Radius (KM)4871,1371,4367501,300
Mass (Earth Masses)20.000160.002130.00070.00070.003
Year Length (Earth Years)4.6248.5283.3309.9557
Day Length (Earth Days)0.386.390.16UnknownUnknown
Surface Gravity (g)30.0030.040.0440.050.08
Surface Temperatureabout -105°Cabout -230°Cabout -240°Cabout -243°Cabout -240°C
Number of moons03201
Notes: 1 1 AU (or Astronomical Unit) = 149,600,000 KM and is the mean distance from the Earth to the Sun
2 1 Earth Mass = 5,980,000,000,000,000,000,000,000 KG : 3 1 g = 9.8 m/s2


Please note that over the weekend of the 26-29th May 2017 we will be switching over to our brand new website - during this time there may be periods where the site is difficult to access, and users will be unable to request observations from the telescope. Please bear with us during this time. All should be back up and running by the 30th May 2017.