Skip to main content Skip to local navigation
Home » Ceres and the Asteroid Belt

Ceres and the Asteroid Belt

Ceres-Dwarf Planet
A picture of Ceres taken by Dawn in February, 2015 from a distance of about 46,000 kilometers.


Ceres is named after the Roman goddess of agriculture.

Ceres is the largest and most massive body in the asteroid belt; its mass is about 1.4% that of the Earth's moon and its diameter is 466km.

1 Cererian day = 9.1 Earth hours; 1 Cererian year = 4.6 Earth years.

It was promoted from asteroid to dwarf planet status by the IAU at the same time that Pluto was demoted to the same position.

NASA's Dawn spacecraft began it's orbit around Ceres in March, 2015, after completing its study of Vesta (another body in the asteroid belt). Astronomers believe that water ice buried under Ceres' crust because its density is less than that of the Earth's crust, and because the dust-covered surface bears spectral evidence of water-bearing minerals. In 2014, the Herschel telescope detected plumes of water vapour coming up from the surface of Ceres.  Astronomers hope that the Dawn mission will shed light on the formation and early conditions of our solar system.

A picture of Vesta in natural colour taken by Dawn in 2011--taken at a distance of about 5200 kilometers.


Vesta is named after the Roman goddess of hearth and home

It is the second most massive object in the solar system; its mass is about 0.4% that of the Earth's moon and its diameter is 530 kilometres.

1 Vestan day = 5.3 Earth hours; 1 Vestan year= 3.6 Earth years

NASA's Dawn spacecraft studied Vesta for about a year before moving on to Ceres. Vesta was completely melted in the past, forming a layered body with an iron core. It endured two major impacts in its southern hemisphere, creating large basins. Dawn has also discovered hydrated materials (minerals containing water molecules) on Vesta's surface. This is significant as astronomers currently think that Earth's water came from asteroids such as Vesta (instead of comets as they had previously thought).