Critical-list minor planet

A critical-list minor planet (critical list numbered object or critical object) is a numbered minor planet whose orbit and position is especially in need of improvement.[1]

The IAU's Minor Planet Center (MPC) regularly publishes a list of these critical objects in their Minor Planet Electronic Circular.[2] The list typically contains asteroids that have been observed at a small number of apparitions, especially on opposition, or that have not been adequately observed for more than 10 years, while other observatories create their own, customized lists.[3] The MPC also lists currently observable critical objects on their website,[4] providing differently formatted lists of orbital elements to the worldwide astrometric community.[5]

As of July 2020, the MPC includes more than a thousand objects in their critical list, half of them being either near-Earth asteroids or distant minor planets which account for 674 and 192 critical objects, respectively.[6]


The lowest numbered critical-list objects are:[6]

See also[]


  1. ^ Monet, A. K. B. (December 1994). "CCD Astrometry of "Critical List" Minor Planets". American Astronomical Society Meeting Abstracts. 185: 43.11. Bibcode:1994AAS...185.4311M.
  2. ^ "Minor Planet Electronic Circulars – Sample MPECs". Minor Planet Center. Retrieved 4 July 2020.
  3. ^ "Critical Lists of Asteroids". Lowell Observatory. Retrieved 4 July 2020.
  4. ^ "Observable Critical-List Minor Planets". Minor Planet Center. Retrieved 4 July 2020.
  5. ^ "Orbital Elements: Critical-List Minor Planets". Minor Planet Center. Retrieved 4 July 2020.
  6. ^ a b "Data Available from the Minor Planet Center – MPCORB.DAT". Minor Planet Center. 26 June 2020. Retrieved 29 June 2020. (doc)

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