Dwarf Planets are similar to our planet in many ways only dwarf planets share their orbits around the sun with other objects such as asteroids or comets.
Being a dwarf planet is like being the cast out of the Universe. You’re too small to be considered a planet, but too big to be classified as any other object. This is a distinct issue that’s caused some controversy in the astronomical community, especially with the declassification of Pluto as a planet into dwarf planet status.
It’s estimated that there around 200 dwarf planets in our solar system and in the Kuiper Belt. The key difference in differentiating a dwarf planet from it’s planetary neighbours is identifying that a planet has cleared other objects in the area of its orbit while a dwarf planet has not.
What is a Dwarf Planet?
A dwarf planet is an object nearing planetary-mass that cannot be categorized as either a planet, nor a natural satellite. Dwarf planets live in direct orbit of a Sun, and are massive enough to maintain it’s own gravity.
What are the sizes of Dwarf Planets?
Within our known Solar System there are 5 known dwarf planets: Ceres, Makemake, Pluto, Eris, and Haumea. Eris and Pluto are the largest, followed by Haumea,Makemake and Ceres in order of mass.
Eris has a diameter of 1455 miles, Pluto has a diameter of 1430 miles, Haumea has a diameter of 892 miles, Makemake has a diameter of 882 miles, and Ceres has a diameter of 590 miles,.
A timeline of Dwarf Planets
- January, 1st, 1801 – Giuseppe Piazzi discovers Ceres.
- February, 18th, 1930 – Pluto is discovered by American astronomer Clyde Tombaugh.
- April, 13th, 1978 – American astronomers James Christy and Robert Harrington discover Charon, a moon of Pluto.
- September, 7th, 2005 – Hubble Space Telescope reveals that Ceres’ body has a nearly round shape.
- January, 8th, 2005 – Scientists using images from ground-based telescopes announce they have discovered a Pluto-sized world billions of miles beyond the orbit of Neptune.
- January, 19th, 2006 – NASA’s New Horizons launches into orbit is on its way to dwarf planet Pluto and the Kuiper Belt region.
- September, 27th, 2007 – A new launch, Dawn, heads into orbit to study two objects in the asteroid belt: asteroid Vesta and dwarf planet, and asteroid, Ceres.
Dwarf Planet Facts
- All the known dwarf planets are smaller than Earth’s moon
- Dawn, which arrived in March of 2015, was the first spacecraft to explore a dwarf planet
- Haumea is named for the Hawaiian fertility goddess
- Makemake is named for a Rapanui (Easter Island) fertility god
- The temperature on pluto is -387 degrees ferenheit
- The discovery of Eris sparked an ongoing debate about the classification of planets
- Due to it’s orbit – the length of one earth year on eris is equivalent to 561 earth years
- Pluto, Eris, and Ceres may even have atmospheres
Dwarf Planet Images
The latest shot of Pluto from NASA’s New Horizons mission.
Pluto’s Moon Charon
An artist’s conception of Eris
The perceived appearance of Makemake
Hamuea, shaped more like a football, than a planet
Image Credit: NASA
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