Small Solar System Body

A Small Solar System Body (SSSB) is an object in the Solar System that is neither a planet, nor a dwarf planet, nor a natural satellite. The term was first defined in 2006 by the International Astronomical Union.

All other objects, except satellites, orbiting the Sun shall be referred to collectively as "Small Solar System Bodies" ... These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

This encompasses all comets and all minor planets other than those that are dwarf planets. Thus SSSBs are: the classical asteroids with the exception of the dwarf planet Ceres; the trojans; and the centaurs and trans-Neptunian objects with the exception of Pluto, Haumea, Makemake, Eris, and others that may turn out to be dwarf planets.

It is not presently clear whether a lower size bound will be established as part of the definition of small Solar System bodies in the future, or if it will encompass all material down to the level of meteoroids, the smallest macroscopic bodies in orbit around the Sun. (On a microscopic level there are even smaller objects such as interplanetary dust, particles of solar wind and free particles of hydrogen.)

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