A meteorite is an object which has fallen to Earth from space. Other, smaller, pieces of extraterrestrial debris also cause meteors, including grains of dust from comets. Meteorites are either stony, in which case they are only slightly heavier than a typical terrestrial rock of the same size, or they are metallic, in which case they are much heavier and ring like a bell when struck with a metallic object. Meteorites that have fallen recently have a distinctive black coating called fusion crust that looks glassy and smooth. Older meteorites are typically weathered and seem to be covered with a fairly smooth dark brown coating.
Most meteorites are magnetic, some strongly, some weakly.
If a corner is broken off and polished, most meteorites will contain numerous small flecks of metal. Contrary to the image sometimes given to them in movies and fiction, meteorites are generally no more radioactive than typical terrestrial rocks, and they do not glow or feel unusually warm to the touch. Positive identification of a meteorite can be difficult and may require an expert. These analyses are usually provided free of charge. In the United States and most countries of the western world individuals can own and trade meteorites, original ownership usually going either to the finder or to the owner of the fall site.