Editing Vulcanoid (section)

{{Short description|Hypothetical asteroids orbiting the Sun}}
{{For|similar sounding terms|Vulcanite (disambiguation)}}
[[File:vulcanoidorbits.svg|right|thumb|270px|The zone, represented by the orange region, in which vulcanoids may exist, compared with the orbits of [[Mercury (planet)|Mercury]], [[Venus]] and [[Earth]]]]
The '''vulcanoids''' are a [[List of hypothetical Solar System objects|hypothetical]] population of [[asteroid]]s that orbit the [[Sun]] in a dynamically stable zone inside the orbit of the planet [[Mercury (planet)|Mercury]]. They are named after the hypothetical planet [[Vulcan (hypothetical planet)|Vulcan]], which was proposed on the basis of irregularities in Mercury's orbit that were later found to be explained by [[general relativity]]. So far, no vulcanoids have been discovered, and it is not yet clear whether any exist.

If they do exist, the vulcanoids could easily evade detection because they would be very small and near the bright glare of the Sun. Due to their proximity to the Sun, searches from the ground can only be carried out during twilight or solar eclipses. Any vulcanoids must be between about {{convert|100|m|ft}} and {{convert|6|km|mi}} in diameter and are probably located in nearly circular orbits near the outer edge of the gravitationally stable zone between the Sun and Mercury. These should be distinguished from [[Atira asteroids]], which may have perihelia within the orbit of Mercury, but whose aphelia extends as far as the orbits of Venus or within Earth's orbital path. Because they cross the orbit of Mercury, these bodies are not classed as vulcanoids.

The vulcanoids, should they be found, may provide scientists with material from the first period of [[planet formation]], as well as insights into the conditions prevalent in the early [[Solar System]]. Although every other gravitationally stable region in the Solar System has been found to contain objects, non-gravitational forces (such as the [[Yarkovsky effect]]) or the influence of a [[planetary migration|migrating planet]] in the early stages of the Solar System's development may have depleted this area of any asteroids that may have been there.