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Centaurs are small solar system bodies with a semi-major axis between those of the outer planets. They generally have unstable orbits because they cross or have crossed the orbits of one or more of the giant planets; almost all their orbits have dynamic lifetimes of only a few million years, but there is one centaur, (514107) 2015 BZ509, which may be in a stable (though retrograde) orbit. Centaurs typically behave with characteristics of both asteroids and comets. They are named after the mythological centaurs that were a mixture of horse and human. It has been estimated that there are around 44,000 centaurs in the Solar System with diameters larger than 1 kilometer.

The first centaur to be discovered, under the definition of the Jet Propulsion Laboratory and the one used here, was 944 Hidalgo in 1920. However, they were not recognized as a distinct population until the discovery of 2060 Chiron in 1977. The largest confirmed centaur is 10199 Chariklo, which at 260 kilometers in diameter is as big as a mid-sized main-belt asteroid, and is known to have a system of rings. It was discovered in 1997. However, the lost centaur 1995 SN55 may be somewhat larger. — Wikipedia

Centaur Object (Eric Weisstein’s World of Astronomy, Wolfram Research)
Chiron (Eric Weisstein’s World of Astronomy, Wolfram Research)


Solar System Exploration: Small Body (NASA)








International Astronomical Union (IAU)










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Knowledge Realm


Law (Constant) Relativity
Force Gravity, Electromagnetism (Light, Color)
Matter (Microscope) Molecule, Atom (Periodic Table), Particle

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Galaxy Milky Way, Andromeda
Planetary System Star, Brown Dwarf, Planet, Moon

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Trans-Neptunian Object
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Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid


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