How Many Moons Does Pluto Have?
How many moons does Pluto have? Pluto, which used to be considered the farthest planet from the sun, has three moons. Pluto is now reclassified as a dwarf planet and not the ninth planet in our solar system. Let’s look at Pluto, how many moons Pluto has, and some other fun facts about the dwarf planet.
Pluto has three moons.
- The largest is Charon. It is half the size of Pluto, which is surprising, because most moons are much smaller than the planets they orbit. If you compare the other moons to their respective planets, Charon would be the biggest. Because Charon is so large, some consider Pluto and Charon to be a double planet.
- The other two moons of Pluto are called Nix and Hydra. They are much smaller than Charon and were only discovered in 2005. They were seen through the Hubble Telescope and named the following year. They are estimated to be between 50 and 60 kilometres in diameter.
The "Planet" Pluto
The diameter of Pluto is 2274 km or 1413 miles. This makes it smaller than seven of the moons in the solar system:
- Moon (Earth)
- Titan (Saturn)
- Triton (Neptune)
Pluto is also smaller than four of the moons of Jupiter:
- Io
- Ganymede
- Europa
- Callisto
It was named after the Roman god of the underworld, because it is so far from the light of the sun.
We don’t know a lot about Pluto because a space probe has not observed it yet. The spacecraft named New Horizons was launched in 2006 and should reach Pluto by 2015. We can make an educated guess that Pluto:
Is about 70% rock and 30% ice made from water
Has an atmosphere of nitrogen, carbon monoxide, and methane
Has a temperature that ranges from -235 to -210 degrees C, or from -391 to -346 degrees Fahrenheit.
Pluto Is Not in the Solar System Anymore
Pluto is the second largest dwarf planet in the solar system next to Eris. Eris has one moon and its orbit is about three times bigger than Pluto’s orbit. It is 27% larger than Pluto and some called it the tenth planet. It was named after the Greek goddess of warfare and strife. She caused jealousy and fighting among men.
Her discovery certainly stirred up a lot of trouble when she was named the tenth planet. Because of future potential discoveries, a meeting of the IAU, the International Astronomical Union, in Prague defined the meaning of planet. On August 24, 2006, Eris and Pluto were designated dwarf planets, along with Ceres, Haumea, and Makemake, and the solar system was said to contain only eight planets.
Pluto and these other dwarf planets are found in an area called the Kuiper Belt, which is similar to the asteroid belt. These planetoids are called KBOs, or Kuiper Belt Objects. Gerard Kuiper had a theory about this belt in 1951, so it was named after him. He thought that some comets might come from it. Most KBOs are made of rock and ice. Names of some other KBOs are: Varuna, Ixion, Quaoar, Orcus, and 1992 QB1.
Moons of the Solar System
Since you know that Pluto has three moons, you might want to know how many moons the other planets and dwarf planets have:
- Mercury and Venus have no moons
- Earth has one moon
- Mars has two
- Jupiter has 63
- Saturn has 60
- Uranus has 27
- Neptune has 13
- Ceres has no moons
- Haumea has two moons
- Makemake has no moons
Moons are formed either as a result of a collision or the effect of the planet’s gravity on a passing body. When a collision happens, debris sometimes gets caught in the planet’s gravity and starts to orbit. Sometimes a passing meteoroid will come too close and the gravitational forces of the planet will pull it into an orbit. When these initial orbits stabilize, then the planet has a new moon.