Hi there! I’m Pluto. I used to be known as the ninth planet in our solar system. But now, I’m called a dwarf planet. This change happened because I didn’t meet all the rules to be a planet. To be a planet, you need to:
1. Go around the Sun.
2. Be big enough to be round.
3. Clear out the space around your path.
I didn’t clear out my path, so now I’m a dwarf planet!
Pluto was discovered in 1930 by an astronomer named Clyde Tombaugh at the Lowell Observatory in Arizona. An 11-year-old girl named Venetia Burney suggested the name “Pluto” after the Roman god of the underworld. Pluto is about 3,736 kilometers wide and has a brownish color.
Besides the eight big planets, there are five known dwarf planets. Four of them are in a place called the Kuiper Belt. Let’s learn about them!
Ceres is the closest dwarf planet to the Sun and the smallest one. It’s in the asteroid belt between Mars and Jupiter. Discovered in 1801 by Giuseppe Piazzi, Ceres is named after the Roman goddess of agriculture. It takes about 4.6 years to go around the Sun and has mysterious white spots on its surface.
Haumea is special because it’s stretched out due to spinning really fast. It takes about 285 years to orbit the Sun and is found in the Kuiper Belt. Haumea has a reddish color and no atmosphere.
Makemake is the third-largest dwarf planet and is also in the Kuiper Belt. It was discovered in 2005 and named after a fertility god from Rapa Nui mythology. Makemake is perfectly round and has no moons.
Eris is even heavier than Pluto and takes about 557 years to orbit the Sun. It’s in a part of the Kuiper Belt called the scattered disk. Eris has an icy surface and no atmosphere.
Varuna is an oval-shaped dwarf planet found in 2000. It spins quickly, taking about 6.34 hours to complete a rotation. Varuna might have water ice on its surface and is also in the Kuiper Belt. It doesn’t have any moons.
Even though I’m not a planet anymore, I’m still part of an amazing group of dwarf planets. Each one of us has something special to teach about space. Thanks for learning about us!
