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Pluto and the Kuiper Belt

Discovery of Pluto

  • Discovered due to irregularities in the orbits of Uranus and Neptune.
  • Percival Lowell was instrumental in predicting Pluto's position and calculating its size and orbit.
  • Lowell's predictions were off by 6 degrees from Pluto's actual position.

Distance from the Sun

  • Pluto is located approximately 40 Astronomical Units (AUs) from the Sun.
  • Its distance makes detailed imaging challenging until advancements in technology, leading to New Horizons' flyby in 2015.

Pluto’s Moon: Charon

  • Charon is Pluto's most significant moon, measuring 600 km in diameter.
  • Charon has the largest size ratio compared to its parent planet among known moons (Pluto-Charon system properties).
  • Other notable moons of Pluto include Hydra and Nix.

The Kuiper Belt

  • Pluto is a prominent object in the Kuiper Belt, a region located beyond Neptune.
  • Owing to improving technology, astronomers have identified over 1,200 objects past Neptune in the Kuiper Belt.
  • The Kuiper Belt primarily consists of icy bodies and has about 100 times the mass of the Asteroid Belt due to its icy composition.

Classification of Pluto

  • Pluto is classified as a dwarf planet based on recent criteria:
    • Orbits the sun
    • Sufficient mass to be round
    • Has cleared its orbital path
  • The classification of dwarf planets has caused controversy among astronomers, leading to mixed opinions regarding Pluto's status.

Plutoids

  • An additional classification called 'plutoid' includes icy dwarf planets located beyond Neptune.

Other Dwarf Planets

  • Key examples of other dwarf planets include:
    • Quoar: 1,200 km across, larger than Ceres, the largest asteroid.
    • Haumea & Makemake: Ranging from 1,500 to 2,000 km in diameter.
    • Eris: Larger than Pluto.
    • Sedna: The furthest known object in our Solar System, located at the inner edge of the Oort Cloud, with a diameter of 1,500 km and a highly elliptical orbit.