Fragments of rock up to  1m wide are called meteoroids.When they enter earth's atmosphere they burn up,producing showers of light called meteors or 'shooting stars'.

By convention asteroids are named after  their discoverer , comets are named after their discoverer but meteorites are named after their landing site.
Meteorites  give scientists unique opportunity to study fragments of the solar system.A meteorites from mars, found in Antarctica in 1984, bore shapes resembling microscopic fossils.