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, all the other dwarf planets are found in the Kuiper Belt. There are another 6 objects in our solar system that are almost certainly dwarf planets and there may be more than 10,000 altogether. Currently none of the dwarf planets have been visited by space probes, though in 2015 NASA’s Dawn and New Horizons missions will reach Ceres and Pluto respectively.

What is Dwarf Planet?

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

A “dwarf planet” is a celestial body that
(a) is in orbit around the Sun,
(b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape,
(c) has not cleared the neighbourhood around its orbit, and
(d) is not a satellite.

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

Sizes of the Dwarf Planets

Dwarf Planets Size Comparison
The largest dwarf planet in the solar system could be either Eris or Pluto followed by Makemake and Haumea with the smallest being Ceres. The order of the dwarf planets from closest to Sun outwards is Ceres, Pluto, Haumea and Makemake with Eris being the furthest from the Sun.

The Dwarf Planets

Name		Distance from Sun		Diameter at Equator
Ceres		413,700,000 km (2.77 AU)	950 km
Pluto		5,874,000,000 km (39.26 AU)	2,368 km
Haumea		6,452,000,000 km (43.13 AU)	1,739 km
Makemake	6,850,000,000 km (45.79 AU)	1,502 km
Eris		10,120,000,000 km (68.01 AU)	2,326 km

Facts About Dwarf Planets

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