Dwarf Planet Facts

There are 5 officially recognised dwarf planets in our solar system, they are Ceres, Pluto, Haumea, Makemake and Eris. With the exception of Ceres, which is located in the asteroid belt, the other dwarf planets are found in the outer solar system. There are another 6 objects in our solar system that are almost certainly dwarf planets and there may as many as 10,000. Of the dwarf planets only 2 have been visited by space probes, in 2015 NASA’s Dawn and New Horizons missions reached Ceres and Pluto respectively.

What is Dwarf Planet?

Dwarf planets share many of the same characteristics as planets though there is one significant difference. The International Astronomical Union’s definition of a dwarf planet is:

A “dwarf planet” is a celestial body that

  1. is in orbit around the Sun,
  2. has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
  3. has not cleared the neighbourhood around its orbit, and
  4. is not a satellite.

The key difference is that a planet has cleared other objects in the area of its orbit while a dwarf planet has not.

Sizes of the Dwarf Planets

Dwarf Planet Sizes Diagram
The Dwarf Planets Ceres, Pluto, Haumea, Makemake and Eris

The largest dwarf planet in the solar system is Pluto followed by Eris, Makemake, Haumea, with the smallest being Ceres. The order of the dwarf planets from closest to Sun outwards is Ceres, Pluto, Haumea, Makemake, with Eris being the furthest from the Sun.

NameDiameterDistance from SunLength of Year
Ceres950 km413,700,000 km4.6 Earth years
Pluto2,372 km5,874,000,000 km248.0 Earth years
Haumea1,960 - 1,518 × 996 km6,452,000,000 km283.3 Earth years
Makemake1,434 × 1,422 km6,850,000,000 km309.9 Earth years
Eris2,326 km10,120,000,000 km560.9 Earth years

Facts About Dwarf Planets

Click a dwarf planet below to find out more about it: