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Planetary Science

Asteroid

Definition

A small rocky body orbiting the Sun, primarily found in the asteroid belt between Mars and Jupiter. Asteroids range from a few meters to hundreds of kilometers in diameter. They are remnants from the early solar system that never coalesced into a planet.

Related Terms

Asteroid Belt

A region of the solar system between the orbits of Mars and Jupiter where most asteroids are found. Despite popular depi...

Near-Earth Object

Any small solar system body whose orbit brings it close to Earth, with a perihelion distance less than 1.3 AU. Includes ...

Meteoroid

A small rocky or metallic body in space, from grain-of-sand to one-meter size. When entering Earth's atmosphere, it crea...

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