asteroid belt

(redirected from Main-belt Asteroid)
Also found in: Dictionary, Thesaurus.

asteroid belt

(main belt) The zone near to the plane of the ecliptic and between the orbits of Mars and Jupiter that contains the majority of asteroids, known as main-belt asteroids. The edges are well-defined at distances from the Sun of about 1.7 and 4.0 AU respectively and the orbits are strongly concentrated in the plane of the ecliptic. Even so, the individual asteroids in the main belt are widely spaced. The orbital inclination becomes more scattered on moving through the belt. The average inclination is about 10° and the average eccentricity is 0.15. All the bodies are in direct motion. Occasional collisions between asteroids occur at velocities of about 5 km s–1. See also Kirkwood gaps.

asteroid belt

[′as·tə‚rȯid ‚belt]
(astronomy)
The region between 2.1 and 3.5 astronomical units from the sun where most of the asteroids are found.
References in periodicals archive ?
In contrast, the Galileo spacecraft could only resolve features measuring some 50 m or larger when it flew by the main-belt asteroids 951 Gaspra in 1991 and 243 Ida in 1993.
Small main-belt asteroids are of keen interest because they have a relatively high probability of being kicked into an Earth-crossing orbit.
All other large main-belt asteroids with one or more moons are very porous," said Emery.
At first glance, that identification wouldn't seem to link meteorites with main-belt asteroids, since (3103) 1982BB does not now reside in the belt.
Such a population would be several hundred times the estimated number of main-belt asteroids in that size range.