Meteors, meteorites, asteroids and comets constantly circle the sun. You may never see a comet or asteroid in person, but you could hold a meteorite in your hand one day. Like meteors, these small objects cross Earth's orbit frequently and enter the atmosphere. When they make it to Earth in one piece, scientists can use special equipment to learn about elements that make up these rocks from space.
Definitions and Clarifications
Different people may call shooting stars different names. A shooting star is a meteor or meteorite that leaves a bright trail as it blazes through the atmosphere. Meteors differ from meteorites because meteorites reach the ground before burning up; meteors do not. Meteors are often surprisingly small and may be no larger than a rice grain. They usually consist of comet fragments while meteorites are often broken pieces of asteroids.
Inside a Meteorite
There's nothing magical about a meteor or meteorite. They consist of elements that you find on Earth and no one has ever found a new element in one of these objects. However, some meteorites may contain elements and minerals that are not common on this planet. For example, scientists found oldhamite in a meteorite they recovered in California. Oldhamite is a calcium sulfide that you rarely find on Earth. In 1948, hundreds of meteorites fell over Colorado, Nebraska and Kansas. One of the largest meteorites was a rare type called enstatite achondrite. These meteorites consist of enstatite -- a mineral composed of silicon, oxygen and magnesium. Enstatite achondrites may also contain rare sulfide minerals such as niningerite.
Sometimes You Find Something New
While meteorites may not contain new elements, they can have new types of minerals that scientists have not seen. For example, in 2011, researchers discovered and named a new mineral "Wassonite" after finding it in an old meteorite that fell in 1969. Wassonite, made of titanium and sulfur, also has a rare crystal structure scientists had not found in nature. The meteorite they recovered probably came from an asteroid that orbited between Jupiter and Mars.
Meteorite Hunting Tips
If you're lucky, you may stumble upon rocks you think could be meteorites. Randy Korotev, a geochemist at Washington University in St. Louis, offers tips on spotting them. He notes that a dark ash-like crust similar to an egg shell surrounds meteorites that fell recently. Over time the crust disappears. He also reports that a meteorite is generally smooth but "often has shallow depressions and deep cavities resembling clearly visible thumbprints in wet clay." Meteorites are also unusually dense and most of them are magnetic.