A minor planet is an astronomical object in direct orbit around the Sun that is neither a dominant planet nor originally classified as a comet. Minor planets can be dwarf planets, asteroids, trojans, centaurs, Kuiper belt objects, and other trans-Neptunian objects. The first minor planet discovered was Ceres in 1801 (although from the time of its discovery until 1851 it was considered to be a planet). The orbits of more than 570,000 objects have been archived at the Minor Planet Center.
The term "minor planet" has been used since the 19th century to describe these objects. The term planetoid has also been used, especially for larger objects. Historically, the terms asteroid, minor planet, and planetoid have been more or less synonymous, but the issue has been complicated by the discovery of numerous minor planets beyond the orbit of Jupiter and especially Neptune that are not universally considered asteroids. Minor planets seen outgassing may receive a dual classification as a comet.
Before 2006 the International Astronomical Union had officially used the term minor planet. During its 2006 meeting, the Union reclassified minor planets and comets into dwarf planets and small Solar System bodies. Objects are called dwarf planets if their self-gravity is sufficient to achieve hydrostatic equilibrium, that is, an ellipsoidal shape, with all other minor planets and comets called "small Solar System bodies". The IAU states: "the term 'minor planet' may still be used, but generally the term 'small solar system body' will be preferred." However, for purposes of numbering and naming, the traditional distinction between minor planet and comet is still followed.
Other articles related to "minor planet, minor planets, planets, planet":
... As minor planet discoveries are confirmed, they are given a permanent number by the IAU's Minor Planet Center, and the discoverers can then submit names for them, following the IAU's naming conventions ... The list below concerns those minor planets in the specified span of numbers that have received names, and explains the meanings of those names ... Besides the Minor Planet Circulars (in which the citations are published), a key source is Lutz D ...
... of comets List of Solar System bodies formerly regarded as planets List of trans-Neptunian objects Meanings of minor planet names Minor planet (for links to articles on particular groups and families ...
... Astronomical Union is dedicated to the Physical Study of Comets Minor Planets ... Archival data on the physical properties of comets and minor planets are found in the PDS Asteroid/Dust Archive ...
... undergone by Ceres is mirrored in the story of Pluto, which was named a planet soon after its discovery by Clyde Tombaugh in 1930 ... Uranus and Neptune had been declared planets based on their circular orbits, large masses and proximity to the ecliptic plane ... tiny Pluto should be reclassified as a minor planet, just as Ceres had been a century earlier ...
... As minor planet discoveries are confirmed, they are given a permanent number by the IAU's Minor Planet Center, and the discoverers can then submit names for them ... The list below concerns those minor planets in the specified span of numbers that have received names, and explains the meanings of those names ... Besides the Minor Planet Circulars (in which the citations are published), a key source is Lutz D ...
Famous quotes containing the words planet and/or minor:
“Have you not budged an inch, then? Such is the daily news. Its facts appear to float in the atmosphere.... We should wash ourselves clean of such news. Of what consequence, though our planet explode, if there is no character involved in the explosion? In health we have not the least curiosity about such events. We do not live for idle amusement. I would not run round a corner to see the world blow up.”
—Henry David Thoreau (18171862)
“A certain minor light may still
Out of kitchen table or chair
As if a celestial burning took
Possession of the most obtuse objects now and then”
—Sylvia Plath (19321963)