Vulcanoid asteroid

hypothetical population of asteroids

Vulcanoid asteroids are a special group of asteroids which may orbit close to the Sun, closer than the orbit of the planet Mercury.[1] No vulcanoid has ever been discovered; it is not known if they ever existed. Because they would orbit so close to the Sun they could only be seen during twilight, or a solar eclipse.[2] Their very small size could make them impossible to see. This part of the Solar System is described as being gravitationally stable, and every other similar stable area has asteroids.[3] If they do exist, vulcanoids would be made of material that could help explain the formation of the planets.[4] If they do not exist, then theories about how the planets were formed might have to change.[5] They are called vulcanoids after a planet, Vulcan, which early astronomers thought they had seen close to the Sun.[6]


  1. Evans, N. Wyn; Tabachnik, Serge (1999). "Possible Long-Lived Asteroid Belts in the Inner Solar System". Nature. 399 (6731): 41–43. arXiv:astro-ph/9905067. Bibcode:1999Natur.399...41E. doi:10.1038/19919. S2CID 4418335.
  2. "Vulcanoids". The Planetary Society. Archived from the original on 2009-01-08. Retrieved 2008-12-25.
  3. Britt, Robert Roy (2004). "Vulcanoid search reaches new heights". Retrieved 2008-12-25.
  4. "NASA Dryden, Southwest Research Institute Search for Vulcanoids". NASA. 2002. Archived from the original on 2019-05-03. Retrieved 2008-12-25.
  5. Campins, H.; Davis, D. R.; Weidenschilling, S. J.; Magee, M. (1996). "Searching for Vulcanoids". Completing the Inventory of the Solar System, Astronomical Society of the Pacific Conference Proceedings. 107: 85–96. Bibcode:1996ASPC..107...85C.
  6. Standage, Tom (2000). The Neptune File. Harmondsworth, Middlesex, England: Allen Lane, The Penguin Press. pp. 144–149. ISBN 0-713-99472-X.