Small Solar System body

The term was first defined in 2006 by the International Astronomical Union (IAU) as follows: "All other objects, except satellites, orbiting the Sun shall be referred to collectively as 'Small Solar System Bodies'".

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.

Except for the largest, which are in hydrostatic equilibrium, natural satellites (moons) differ from small Solar System bodies not in size, but in their orbits.

Some of the larger small Solar System bodies may be reclassified in future as dwarf planets, pending further examination to determine whether or not they are in hydrostatic equilibrium.

These two belts possess some internal structure related to perturbations by the major planets (particularly Jupiter and Neptune, respectively), and have fairly loosely defined boundaries.

Euler diagram showing the types of bodies in the Solar System
Positions of the main asteroid belt, Kuiper belt, and the Oort cloud in the Solar System
The Sun, the planets, their moons, and several trans-Neptunian objects The Sun Mercury Venus The Moon Earth Mars Phobos and Deimos Ceres The main asteroid belt Jupiter Moons of Jupiter Rings of Jupiter Saturn Moons of Saturn Rings of Saturn Uranus Moons of Uranus Rings of Uranus Neptune Moons of Neptune Rings of Neptune Pluto Moons of Pluto Haumea Moons of Haumea Makemake S/2015 (136472) 1 The Kuiper Belt Eris Dysnomia The Scattered Disc The Hills Cloud The Oort Cloud