Ancient Space Debris

Fragments of asteroids or comets that enter Earth’s atmosphere are called meteors. If the fragments reach the ground intact, they are called meteorites. These range in size from dust-sized particles to large masses. Scientists analyze the chemical and mineralogical properties of meteorites for clues about how Earth and other bodies in our solar system formed.

Meteorites are some of the oldest items found on Earth. In fact, the approximate age of Earth (4.5 billion years) is based in part on radiometric dating of meteorites, because the oldest surviving rocks on Earth are slightly younger.

Meteorites fall into one of three main classes:

• Stony meteorites are rich in silicate minerals.
• Iron meteorites are enriched with elemental iron alloyed with nickel.
• Stony-iron meteorites are mixtures of silicates and iron-nickel.

Explore Further

Ohio has only 14 confirmed meteorite finds. Click here to learn more about Ohio meteorites and other astrogeology topics from the ODNR Division of Geological Survey.