词条 | Dwarf planets |
释义 | Dwarf planets Table Dwarf planets name mean distance from Sun (AU) orbital period (years) diameter (km) year of discovery notable features Official dwarf planets* Ceres 2.77 4.61 980 × 910 1801 largest known asteroid; first asteroid discovered Pluto 39.5 247.69 2,344 1930 has three moons Haumea 43.19 283.84 980 × 750 × 500 2003 rotates every 3.9 hours; has elongated shape Makemake 45.48 306.17 1,500 2005 reddish in colour Eris 67.84 558.77 2,600 2003 surface coated with methane ice Notable candidate dwarf planets Orcus 39.22 245.62 946 2004 named after Roman god of the underworld 2003 AZ84 39.36 246.94 686 2003 has one moon Ixion 39.70 250.18 650 2001 named after Greek mythological king sentenced to roll a wheel through the underworld 90568 (2004 GV9) 42.10 273.13 677 2004 discovered by U.S. robotic telescopes (telescope) searching for near-Earth asteroids 55636 (2002 TX300) 43.28 284.69 \\<800 2002 possible fragment formed from collision with Haumea Quaoar 43.61 287.97 844 2002 named after the creator god of the Tongva Indians 55565 (2002 AW197) 47.12 323.49 735 2002 discovered by U.S. astronomers at Palomar Observatory Sedna 488.98 10,812.82 \\<1,600 2003 has extremely eccentric orbit that takes it as far as 975 AU from the Sun *As defined by the International Astronomical Union (information processing). See as table: ![]() |
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