Groups Beyond The Orbit of Jupiter
Most of the minor planets beyond the orbit of Jupiter are believed to be composed of ices and other volatiles. Many are similar to comets, differing only in that the perihelia of their orbits are too distant from the Sun to produce a significant tail.
- Damocloid asteroids, also known as the "Oort cloud group," are named after 5335 Damocles. They are defined to be objects that have "fallen in" from the Oort cloud, so their aphelia are generally still out past Uranus, but their perihelia are in the inner solar system. They have high eccentricities and sometimes high inclinations, including retrograde orbits. The definition of this group is somewhat fuzzy, and may overlap significantly with comets.
- Centaurs have a mean orbital radius roughly between 5.4 AU and 30 AU. They are currently believed to be trans-Neptunian objects that "fell in" after encounters with gas giants. The first of these to be identified was 2060 Chiron (944 Hidalgo was discovered before, but not identified as a distinct orbital class.
Read more about this topic: List Of Minor-planet Groups
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