Parent bodies

Part of Hall of Meteorites.


In just a few thousand years, the solar system evolved from a collection of small particles sticking together to an assortment of larger bodies known as planetesimals—precursors of the planets. Today, fragments of this primordial material fall to Earth as meteorites, although pieces of the same object do not necessarily fall at the same time. Scientists have identified groups of meteorites with the same composition—and have concluded that members of the same group were probably once part of the same "parent body." Evidence suggests that the tens of thousands of meteorites discovered to date are fragments of fewer than 200 parent bodies.

Today most parent bodies exist in the asteroid belt, located between the planets Mars and Jupiter. But initially, these bodies could be found throughout the solar system. As parent bodies formed in the early solar system, some incorporated more of certain ingredients than others. These differences are crucial to our ability to trace family ties among groups of meteorites.