Minor planets in the context of List of minor planets visited by spacecraft


Minor planets in the context of List of minor planets visited by spacecraft

⭐ Core Definition: Minor planets

According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term minor planet, but that year's meeting reclassified minor planets and comets into small Solar System bodies (SSSBs) and dwarf planets, including into the respective categories comets and Pluto, which were generally not considered minor planets. In contrast to the eight official planets of the Solar System, all minor planets fail to clear their orbital neighborhood.

Minor planets include asteroids (near-Earth objects, Earth trojans, Mars trojans, Mars-crossers, main-belt asteroids and Jupiter trojans), as well as distant minor planets (Uranus trojans, Neptune trojans, centaurs and trans-Neptunian objects), most of which reside in the Kuiper belt and the scattered disc. As of October 2025, there are 1,472,966 known objects, divided into 875,150 numbered, with only one of them recognized as a dwarf planet (secured discoveries) and 597,816 unnumbered minor planets, with only five of those officially recognized as a dwarf planet.

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👉 Minor planets in the context of List of minor planets visited by spacecraft

The following tables list all minor planets and comets that have been visited by robotic spacecraft.

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Minor planets in the context of List of unnumbered minor planets

The following is a list of unnumbered minor planets in chronological order of their principal provisional designation. Contrary to their numbered counterparts, unnumbered minor planets have a poorly determined orbit due to insufficient observational data. This also includes lost minor planets which have not been observed for many years, or even decades. As of August 2023, the Minor Planet Center (MPC) accounts for 676,755 unnumbered minor planets which represent 52% of the overall minor planet population. Unnumbered minor planets can be further divided into 129,103 single-opposition objects with short observation arcs, prone to mismatch and loss, and 547,652 objects that have been observed multiple times during opposition, when astrometric conditions are most favorable. The JPL Small-Body Database gives a running total of 676,786 unnumbered minor planets.

The tables below contain 115 objects with a principal designation assigned between 1927 and 1994. Additional partial lists cover the period from 1995 to 2004. Unnumbered minor planets detected after 2004 are not listed due to their large number. The orbital uncertainty parameter (U) ranges from low ("0") to very high ("9"). For some single-opposition objects no numeric uncertainty is given ("–"), with "E" indicating an estimated, rather than determined orbital eccentricity. Furthermore, a color code is used to indicate a body's basic dynamical classification, with additional information given in columns "class" and "description and notes" (especially for near-Earth objects, Jupiter trojans and distant objects). If available, mean diameters are taken from the latest NEOWISE publication, or, if not available, estimated based on an object's absolute magnitude and displayed in italics.

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Minor planets in the context of Cuno Hoffmeister

Cuno Hoffmeister (2 February 1892 – 2 January 1968) was a German astronomer, observer and discoverer of variable stars, comets and minor planets, and founder of Sonneberg Observatory.

Born in Sonneberg in 1892 to Carl and Marie Hoffmeister, Cuno Hoffmeister obtained his first telescope in 1905 and became an avid amateur astronomer. After his father lost most of his money in 1914, Hoffmeister had to leave school in 1916 to start an apprenticeship in his father's company. During this time he continued to study spherical mathematics and trigonometry. In April 1915 he had the opportunity to substitute as the assistant of Ernst Hartwig at Remeis Observatory in Bamberg while the current holder of the position was drafted, mainly working on observations of meteors and variable stars. He held this position until the end of the war and then moved back to Sonneberg, where he made his Abitur in 1920.

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