Dwarf Planets are the worlds in our solar system that directly orbit the Sun, like planets. In the definition of planets and dwarf planets, there is only one significant difference that dwarf worlds have not cleared the neighborhood objects around their orbit.
In 2006, the International Astronomical Union (IAU) categorized the objects orbiting the sun into three divisions:
- Planets
- Dwarf Planets
- Small Solar System Bodies
Around 1800 AD astronomers have discovered several celestial bodies between planets Mars and Jupiter. They used to consider these bodies as a planet. But when the number of bodies increases continually astronomers classify another category and started using the word asteroid for some celestial bodies.
Pluto was discovered in 1930 and then astronomers used to classify the solar system celestial bodies into 9 planets and several hundreds of asteroids and comets. But in 2005 after the discovery of Eris (a dwarf planet), IAU and astronomers proposed a definition of planets and dwarf planets in our solar system.
| Check About:- Difference – Comets? Asteroids? Meteoroids? Meteor? Meteorites? |
Dwarf Planets vs Planets
Here in this article, we have mentioned what is the definition of dwarf planets vs planets? This definition is given according to the International Astronomical Union (IAU).
According to IAU, the planet is a celestial body that:
- orbit around the sun,
- has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape (almost round shape),
- has cleared the neighborhood around its orbit.
| Read About:- 8 Solar System Planets |
According to IAU, the dwarf planet is a celestial body that:
- orbit around the sun,
- has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium shape (almost round shape),
- has not cleared the neighborhood around its orbit,
- is not a satellite.
So there is only one difference in-between a planet and a dwarf planet, that a dwarf planet has some neighborhood objects in its orbit. These neighborhood objects may be some asteroids, debris, and smaller bodies.
Planets are comparatively large and massive, so they have enough gravitational force to clear the neighborhood object. Whereas a Dwarf Planet lacks mass and so unable to clear the smaller neighborhood objects.
Dwarf Planets List in our Solar System
According to the International Astronomical Union (IAU), there are 8 planets and 5 officially recognized dwarf planets in our solar system.
These 8 planets are “Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune”. Whereas 5 dwarf planets in our solar system are “Pluto, Ceres, Eris, Haumea, and Makemake” and these 5 are officially accepted by IAU.
There are other dwarf worlds in our solar system that has not considered by IAU yet. These are known as “near-certain”, “most-likely”, or “possible” dwarf planets.
According to an estimation, there may be more than 10,000 of the near-certain dwarf planets in our solar system. And only in the Kuiper belt region, there may be over 200 in numbers of it.
| Must Check:- Kuiper Belt: Facts and other Information |
Here is given some possible dwarf planets list in our solar system that is not officially recognized by IAU:
- Quaoar
- Sedna
- Orcus
- 2007 OR10
- Salacia
- 2002 MS4
- 10 Hygiea.
Those above 7 mentioned list of dwarf planets come in the category of “near-certain” or “most likely” dwarf worlds. These are also known as ‘minor planets’ (Minor Planets = Dwarf Planets + Small Solar System Bodies).
Here in the below picture, some dwarf planets list (Possible + IAU Recognized) are added with their size.
Dwarf planets list with increasing diameter
Dwarf Planets in Order
The naming committee of the IAU has decided some of the Trans-Neptunian Objects as a most likely dwarf planet. (Transneptunian objects are those object that orbits around the sun with higher distance than planet Neptune).
Here we have given a list of dwarf planets in order with increasing distance from the sun and where they located in the solar system. In the below table both dwarf planets are listed as ‘near-certain’ as well as ‘IAU defined’.
| Dwarf Planets | Distance from sun | Location in the solar system |
| Ceres | 2.77 AU | Asteroid belt |
| Orcus | 39.40 AU | Kuiper belt |
| Pluto | 39.47 AU | Kuiper belt |
| Salacia | 42.20 AU | Kuiper belt |
| Haumea | 43.20 AU | Kuiper belt |
| Quaoar | 43.69 AU | Kuiper belt |
| Makemake | 45.56 AU | Kuiper belt |
| 2007 OR10 | 67.38 AU | scattered disc |
| Eris | 67.78 AU | scattered disc |
| Sedna | 506.70 AU | Detached |
Dwarf planets in order from the Sun
As given in the table, Ceres is the closest dwarf planet in our solar system and it is also IAU-defined. The IAU-defined farthest dwarf planet is Eris and is located in the scattered disc with a distance of around 67.78 AU from the sun.
1. Largest Dwarf Planet (Pluto)
Pluto is the largest dwarf planet in our solar system with a diameter of approximately 2380 km. It used to be a planet but in 2006 IAU decided to re-classify it into the dwarf planets category. Though Pluto has a small size compared to our earth, still it has 5 moons/natural satellites.
Pluto Dwarf Planet
- To know more especially about Pluto, check the following link: Pluto facts and information: Dwarf planet pluto
2. Smallest Dwarf Planet (Ceres)
Ceres is the smallest dwarf planet in our solar system with a diameter of approximately 940 km. It is located in the region of the Asteroid belt. The astronomers have discovered Ceres around 1801. So this is the earliest known dwarf planet by astronomers.
- Read in detail:- Ceres dwarf planet: Amazing facts and information
New dwarf planets:-
According to officially recognized by International Astronomical Union (IAU) new dwarf planets are Eris, Haumea, and Makemake.
3. Eris
Eris has one known moon and was discovered in January 2005. Between 2005 to 2006 it was considered as 10th planet of our solar system by most astronomers. Eris re-classified into the dwarf planet in 2006 by IAU.
- Read about:- Eris Dwarf Planet- Facts and Information
4. Haumea
Haumea was discovered in December 2004. It was not considered as a dwarf planet by the naming committee of IAU till July 2008. It has 2 moons that orbit around it. Haumea is famous for its oval shape.
Haumea Dwarf Planet
- Read in detail:- Haumea Dwarf Planet Facts and Information
5. Makemake
Makemake was discovered in July 2005 and announced as a dwarf planet by the naming committee of IAU in 2008. It has one known natural satellite. This dwarf planet was discovered around Ester (a festival) in 2005, so it is also known as an ‘Easterbunny’.
- Read about:- Makemake Facts: Dwarf planet Makemake
These are the 5 dwarf planets in our solar system recognized and considered by IAU. There are thousands of more objects in the solar system to discover that maybe a dwarf planet or most likely it.
