Parent body
The asteroid, moon or planet that a meteorite was originally part of before it was knocked off into space.
Every meteorite was once part of something bigger. That original object is called its parent body. A collision between asteroids, or a big impact on a planet or moon, breaks off pieces that wander through space, sometimes for millions of years, before a few happen to land on Earth.
Working out the parent body tells scientists where a rock comes from and what that world was like. Meteorites belonging to the same group share chemistry and oxygen isotopes (forms of the same element with different masses), which suggests they came from the same parent. For most groups the actual parent is unknown, but a few have been identified with good confidence: some meteorites come from the Moon, some from Mars, and the HED family most likely from the asteroid Vesta.
A good example is the eucrite Millbillillie, which fell in Western Australia in 1960. Its make-up matches what the Dawn spacecraft measured on Vesta's surface. Parent bodies are recognised through laboratory tests, by comparing a meteorite's minerals and isotopes with spacecraft data or telescope light patterns from asteroids, so you cannot spot one just by looking at a stone.
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Level: Explorer Ages 10 and up