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Meteoroids, when small pieces of asteroids break off

An asteroid is a small rocky object that orbits the Sun, mostly between the orbits of Mars and Jupiter. Sometimes one asteroid can smash into another. This can cause small pieces of the asteroid to break off. Those pieces are called meteoroids

Asteroids are smaller than a planet, but they are larger than the pebble-sized meteoroids. Its sizes range from 1 meter to about 1000 km. They are also called minor planets.

Meteor, when pieces burn up in the atmosphere

A meteor is what happens when a meteoroid – a small piece of an asteroid or comet – burns up upon entering Earth’s atmosphere, creating a streak of light in the sky. 

Origin of dust debris particles in space

Many meteoroids come from comets: these objects are often called “dirty snowballs” because they contain a lot of ice that sublimates when they come close to the Sun.

This drives a gas flux into the adjacent vacuum while drag forces from the expanding gas are exerted on embedded dust and debris particles, expelling them into interplanetary space. Meteoroid streams, consisting of large particles ejected at low speeds and confined to move approximately in the orbit of the parent body, are one result.

On the other hand, meteoroids can also originate from asteroids. The Geminid meteoroid stream and asteroid 3200 Phaethon are probably the best-known examples.

If a piece of this asteroid or its moon breaks off, it could become a meteoroid. Credits: NASA.
Giant asteroid Vesta. Photograph obtained with NASA's Dawn spacecraft looking down at Vesta's north pole as it was departing in 2012. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA