What is a Vulcanoid Asteroid?
The Vulcanoids are a postulated asteroid group that may orbit in a gravitationally stable region between 0.08 and 0.21 astronomical units (Sun-to-Earth lengths) from the Sun. By comparison, the planet Mercury orbits the Sun at a distance of between 0.3 and 0.46 astronomical units. Confirming or disconfirming the existence of the Vulcanoids is very difficult because of the Sun’s glare. Astronomers have been looking for the Vulcanoids since an eclipse in 1901, but have yet to have any luck. Vulcanoids are named after Vulcan, a hypothetical planet postulated to explain unusual motions in Mercury’s orbit. These variations were later explained by Einstein’s theory of general relativity, eliminating the need for a Vulcan. There are various reasons why we should expect the Vulcanoid asteroids to exist. Other dynamically stable regions of the solar system, such as the asteroid belt and the Kuiper Belt, contain numerous asteroids, making little reason to expect the Vulcanoid belt to be empty. M
• We know today there is no Planet Vulcan • Even under the 2006 IAU definition • Asteroids in Planet Vulcan region called Vulcanoids • Even under the 2006 IAU definition • A Vulcanoid asteroid: • Has a semi-major axis > Mercurys semi-major axis • Has a semi-major axis > than Mercury’s semi-major axis • In round figures: “Inside Mercury’s orbit”
