Asteroids are minor planets, especially those o the inner Solar Seestem. The lairger anes hae an aa been cried planetoids. These terms hae historically been applied tae ony astronomical object orbitin the Sun that did nae shaw the disk o a planet an wis nae observed tae hae the characteristics o an active comet, but as minor planets in the ooter Solar Seestem wur discovered, thair volatile-based surfaces wur foond tae mair closely resemble comets an so wur eften distinguished frae tradeetional asteroids.[1] Thus the term asteroid haes come increasingly tae refer specifically tae the smaa bodies of the inner Solar System out to the orbit o Jupiter. Thay are grouped wi the ooter bodies—centaurs, Neptune trojans, an trans-Neptunian objects—as minor planets, which is the term preferred in astronomical circles.[2] In this airticle the term "asteroid" refers tae the minor planets o the inner Solar Seestem.

253 Mathilde, a C-type asteroid measurin aboot 50 kilometre (30 mi) athort, covered in craters hauf that size. Photograph taken in 1997 bi the NEAR Shoemaker probe.


  1. "Asteroids". NASA – Jet Propulsion Laboratory. Retrieved 13 September 2010.
  2. Asimov, Isaac, and Dole, Stephen H. Planets for Man (New York: Random House, 1964), p.43.