Asteroid belt

The region between Mars and Jupiter containing most of the Solar System’s known asteroids. Its bodies are spread so widely that spacecraft can pass through it with little collision risk.

Asteroid: A small rocky or metallic body orbiting the Sun, too small to qualify as a planet. The belt is defined by the concentration of these bodies.
Kirkwood gap: A region in the asteroid belt with relatively few asteroids, associated with orbital resonances with Jupiter. These gaps show how Jupiter can destabilize particular asteroid orbits.
Nice model: A model of Solar System evolution in which the giant planets migrated and underwent orbital rearrangement. It offers a route for scattering and repopulating small bodies in the belt.
Dawn (spacecraft): A NASA mission that orbited Vesta and Ceres, the two largest bodies in the asteroid belt. Its observations compared a rocky differentiated asteroid with a water-rich dwarf planet.
Protoplanetary disk: A rotating disk of gas and dust surrounding a young star, where planets and smaller bodies form. The belt is leftover material from the disk that formed the Solar System.
Yarkovsky effect: A small change in an object's orbit caused by the recoil of thermal radiation from its surface. It gradually moves asteroids into resonances that can send them out of the belt.
Grand Tack hypothesis: A model in which Jupiter migrated inward and then outward, changing course through interactions with Saturn. Its migration can explain the belt's small mass and broad compositional range.
Hayabusa2: A Japanese spacecraft that collected samples from the near-Earth asteroid Ryugu and returned them to Earth. Its sample mission provides a comparison with material originating in the broader small-body population.
Jupiter: The largest planet in the Solar System, with a powerful gravitational influence on nearby small bodies. Its gravity strongly shapes asteroid belt orbits and gaps.
Asteroid collision: An impact between asteroids that can fragment them or combine their material. Collisions continually reshape the belt and produce asteroid families.

Linked from 26 pages