solar system object

Solar system objects (SSOs), i.e., astronomical objects within the solar system include:

• the Sun (though sometimes the term solar system object is used to mean objects orbiting the Sun).
• the eight planets, four in the inner solar system (Mercury, Venus, Earth, and Mars) and four in the outer solar system (Jupiter, Saturn, Uranus, and Neptune).
• minor planets, rocky objects smaller than the eight planets.
• comets.
• moons (natural satellites).

Meteoroids might also be meant to be included. There are numerous terms for classes of minor planet (and in some cases, also including some comets) based upon various criteria, among them:

• dwarf planets (spherical but not as massive as planets): Pluto, Ceres, Haumea, Makemake, and Eris (there may be more and some additional known objects are candidates).
• SSSBs (small solar system bodies, a recently-coined term for any comet and any minor planet other than a dwarf planet).
• asteroids (used either strictly for minor planets within the asteroid belt or more loosely for any minor planet, but most often used for those within the inner solar system).
• near-Earth objects (NEOs, i.e., asteroids and comets with orbits that near or cross Earth's orbit).
• centaurs (minor planets and comets orbiting between Jupiter and Neptune).
• trans-Neptune objects (TNOs, i.e., comets and other SSSBs beyond Neptune).
• Kuiper Belt objects (KBOs, i.e., TNOs within the Kuiper Belt).
• scattered disk objects (SDOs, i.e., TNOs with substantial eccentricity and orbital inclination).

The Oort Cloud, further out than the Kuiper Belt consists of long-period comets at the far end of their orbits, and presumably more comets essentially floating out there but that can become long-period comets from an encounter.

Identification of an object as a solar system object (e.g., in surveys for transients) generally consists of noting movement of the object across the celestial sphere over successive observations.

Observed astronomical objects that are not solar system objects include (other) stars, as well as galaxies and clouds. Also, any objects that are moving too quickly to be orbiting the Sun, such as 1I/'Oumuamua: these are termed interstellar objects even if they are physically located within the solar system.