minor planet

The term minor planet means a solar system body other than the "normal" (8) planets, and other than comets and moons. The International Astronomical Union (IAU) has declared no current standard usage for the term, but it is and was a term including dwarf planets, asteroids, centaurs, trans-Neptune objects, and many near-Earth objects and KBOs. The exclusion of comets presents a difficulty: an object may be identified (i.e., its orbit determined and recorded), with no comet-characteristics observed, yet the possibility may remain that such characteristics will be discovered in the future; a body classified as a minor planet may later be considered a comet. This situation can persist for years, even centuries or millennia. Also, a body might show some characteristics of a comet but not distinctly enough to classify it to be a comet, making it a (somewhat) comet-like minor planet.

The IAU-coined term SSSB (for small solar system body) covers both comets and those minor planets smaller than dwarf planets, avoiding the terminology-difficulty described above. Referring to an SSSB (which is possibly a minor planet) as a numbered object says it is an object for which a which a permanent number has been assigned, implying there has been sufficient observation that it is assumed to be identifiable by future observations. Before this is established, such a candidate may have a provisional designation.