Pluto: A Dwarf Planet
Guess what?Pluto has more in common with Triton, Neptune's largest moon, than it does with any of the eight planets in our solar system. Pluto is actually smaller than Triton.
Pluto is tilted 122.5 degrees on its axis, which basically means that it is rotating on its head!
. Pluto has an extreme elliptical
orbit. Because of the shape of Pluto's orbit, it actually slips inside of
Neptune's orbit once every 248 Earth years for a period of twenty years. Pluto has
three natural satellites. One of these moons, Charon, is half the size of Pluto and is located close to Pluto. Two additional moons, called Nix and Hydra, were discovered in 2005. They are small and located much farther away from Pluto that Charon is located.
Studies conducted using a spectroscope have detected methane frost on Pluto and water frost on Charon. Like Triton, Neptune's satellite, Pluto has an atmosphere of nitrogen and methane. Pluto's atmosphere appears to extend out to include Charon, which suggests that they may share an atmosphere. Through the Hubble Space Telescope, Charon appears to be more blue in color than Pluto. During the time in its orbit when Pluto is farthest from the Sun, its atmosphere condenses and falls to the surface as frost.
After its discovery in 1930, Pluto was classified as the ninth solar system planet. However, as scientists learned more about our solar system, it was realized that Pluto had little in common with the other eight planets. Pluto was re-classified as a dwarf planet in August 2006.
A QuestionWhat is so unusual about Pluto's moon Charon?
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