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Dwarf planet, Sedna

Average distance from the Sun     11,369,438,172 km / 76 AU — 140,173,204,837 km / 937 AU
Diameter     1,800 km
Mass     1e21 kg
Orbital period around the Sun     about 11,400 Earth years / 4,161,000 Earth days
Number of moons     unknown
On March 15, 2004, a team of NASA astronomers announced the discovery of Sedna—a large planetary body located within the Oort Cloud. Sedna is in an orbital distance that is roughly three times farther out than that of Pluto or Neptune. Based on its current distance, brightness, and presumed ability to reflect light, Sedna has been estimated to be more than half the diameter of Pluto and may be larger than any other planetary body found since Pluto. Sedna is the second most reddish planetary body in the Solar System, after Mars.

Our Solar System

Our solar system is located on the edge of a spiral arm called Orion’s Arm, and is one-half to two-thirds of the way (28,000 light-years) from the center of our Milky Way galaxy.

The Sun, Sol

The Inner Planets
    The Moon

The Asteroid Belt
  Dwarf planet, Ceres
  Asteroid, Ida
  Asteroid, Vesta
  Asteroid, Eros

The Outer Planets

The Kuiper Belt
  Dwarf planet, Pluto
  Dwarf planet, Eris

The Oort Cloud
  Dwarf planet, Sedna
  Comet Halley
  Comet Hale-Bopp

  Glossary of Terms
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