Of the15,000 numbered asteroids, approximately one half of them are named, and only a few thousand are named after people. Asteroids are bodies of rock and iron, usually 10-50 km in diameter, in stable orbits around our solar system's star, the Sun. Even with the most powerful Earth-based telescopes, asteroids appear as just points of light, like stars. Most of the asteroids in our solar system are in a belt between the orbits of the planets Mars and Jupiter. If not for the powerful gravitational pull exerted by the massive planet Jupiter, the hundreds of thousands of asteroids probably would have joined together to become a planet during the formation of our solar system.
Meteorites are pieces of asteroids.
They break off of asteroids during chance collisions with other asteroids and can spend millions of years orbiting the sun before they fall to Earth. Meteorites range in mass from less than a gram to more than 50 tons. The largest meteorite, estimated to weigh more than 60 tons and found in 1920, remains where it fell in Namibia. NMNH has the largest and most important museum collection of meteorites in the world. Over 20,000 specimens from 10,000 different meteorites are in the collection.