Meteoroids are interplanetary metallic and stony objects, and are probably the remains of comets and fragments of shattered asteroids.  They range in size from a fraction of a millimeter to a few hundred meters.  They circle the Sun in elliptical orbits and strike the Earth from all directions at very high speeds, which is increased by the Earth's gravitational pull.

When they strike the Earth's atmosphere, they are become luminous.  They are then called Meteors or popularly "Shooting Stars" or "Falling Stars".  Larger ones may strike the Earth's surface although most are completely vaporized.  They are then called Meteorites.  When they strike the surface, they form craters.  The one in Winslow, Arizona is 25,000 years old. The largest known meteorite with a mass over 55,000 kg fell in southwest Africa..  The largest found in North America with a mass of 36,000 kg. fell near Cape York, Greenland, and is now at Hayden Planetarium in New York City.  They vary in size and shape and are classified as stones (94%) composed of silicate minerals, irons (mainly iron with  5% to 20% nickel, or a combination (Stony irons)

An extremely old meteorite fell in Canada in 1915.  For details, click below