A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples "bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater.
The Tunguska event was an approximately 12-megaton explosion that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate, Russia, on the morning of June 30, 1908. The explosion over the sparsely populated Eastern Siberian Taiga flattened an estimated 80 million trees over an area of 2,150 km2 (830 sq mi) of forest, and eyewitness reports suggest that at least three people may have died in the event. The explosion is generally attributed to a meteor air burst: the atmospheric explosion of a stony asteroid about 50–60 metres in size. The asteroid approached from the east-southeast, and likely with a relatively high speed of about 27 km/s (60,000 mph). It is classified as an impact event, even though no impact crater has been found; the object is thought to have disintegrated at an altitude of 5 to 10 kilometres rather than having hit the surface of the Earth.
A meteoroid is a small rocky or metallic body in outer space.
An impact event is a collision between astronomical objects causing measurable effects. Impact events have physical consequences and have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and biospheric consequences, though atmospheres mitigate many surface impacts through atmospheric entry. Impact craters and structures are dominant landforms on many of the Solar System's solid objects and present the strongest empirical evidence for their frequency and scale.
A Martian meteorite is a rock that formed on Mars, was ejected from the planet by an impact event, and traversed interplanetary space before landing on Earth as a meteorite. As of September 2020, 277 meteorites had been classified as Martian, less than half a percent of the 72,000 meteorites that have been classified. The largest complete, uncut Martian meteorite, Taoudenni 002, was recovered in Mali in early 2021. It weighs 14.5 kilograms and is on display at the Maine Mineral & Gem Museum.
The Wold Cottage meteorite fell near Wold Cottage farm in 1795, a few miles away from the village of Wold Newton in Yorkshire, England.
An iron meteorite fell on the Sikhote-Alin Mountains, in southeastern Russia, in 1947. Large iron meteorite falls have been witnessed and fragments recovered but never before, in recorded history, a fall of this magnitude. An estimated 23 tonnes of fragments survived the fiery passage through the atmosphere and reached the Earth.
The Murchison meteorite is a meteorite that fell in Australia in 1969 near Murchison, Victoria. It belongs to the carbonaceous chondrite class, a group of meteorites rich in organic compounds. Due to its mass and the fact that it was an observed fall, the Murchison meteorite is one of the most studied of all meteorites.
Mesosiderites are a class of stony–iron meteorites consisting of about equal parts of metallic nickel-iron and silicate. They are breccias with an irregular texture; silicates and metal occur often in lumps or pebbles as well as in fine-grained intergrowths. The silicate part contains olivine, pyroxenes, and Ca-rich feldspar and is similar in composition to eucrites and diogenites.
Nakhla is a Martian meteorite which fell in Egypt in 1911. It was the first meteorite reported from Egypt, the first one to suggest signs of aqueous processes on Mars, and the prototype for Nakhlite type of meteorites.
The Carancas impact event refers to the fall of the Carancas chondritic meteorite on September 15, 2007, near the village of Carancas in Peru, close to the Bolivian border and Lake Titicaca. The impact created a small crater in the clay soil and scorched earth around its location. A local official, Marco Limache, said that "boiling water started coming out of the crater, and particles of rock and cinders were found nearby", as "fetid, noxious" gases spewed from the crater. Surface impact occurred above 3,800 metres (12,500 ft).
Gao–Guenie is a H5 ordinary chondrite meteorite that fell on Burkina Faso, West Africa, on March 5, 1960. The fall was composed of many fragments and it is one of the largest observed meteorite showers in Africa to date.
2008 TC3 (Catalina Sky Survey temporary designation 8TA9D69) was an 80-tonne (80-long-ton; 90-short-ton), 4.1-meter (13 ft) diameter asteroid that entered Earth's atmosphere on October 7, 2008. It exploded at an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. Some 600 meteorites, weighing a total of 10.5 kilograms (23.1 lb), were recovered; many of these belonged to a rare type known as ureilites, which contain, among other minerals, nanodiamonds.
Neuschwanstein was an enstatite chondrite meteorite that fell to Earth on 6 April 2002 at 22:20:18 GMT near Neuschwanstein Castle, Bavaria, at the Germany–Austria border.
The Weston meteorite is an H4 ordinary chondrite meteorite which fell to earth above the town of Weston, Connecticut on the morning of December 14, 1807.
The Middlesbrough Meteorite fell in Middlesbrough, North Yorkshire, England on 14 March 1881.
The Tissint meteorite is a Martian meteorite that fell in Tata Province in the Guelmim-Es Semara region of Morocco on July 18, 2011. Tissint is the fifth Martian meteorite that people have witnessed falling to Earth, and the first since 1962. Pieces of the meteorite are on display at several museums, including the Museum of Natural History of Vienna and the Natural History Museum in London.
This is a glossary of terms used in meteoritics, the science of meteorites.
The Angra dos Reis meteorite is the type specimen of the angrite group. It was observed when it fell to earth in 1869.
Millbillillie meteorite is a meteorite named after the cattle station in Western Australia on which it fell in October 1960. It is classified as a eucrite achondrite, a kind of stony meteorite.
