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.
A meteoroid is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide. Objects smaller than meteoroids are classified as micrometeoroids or space dust. Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars.
M-type asteroids are a spectral class of asteroids which appear to contain higher concentrations of metal phases than other asteroid classes, and are widely thought to be the source of iron meteorites.
The Tagish Lake meteorite fell at 16:43 UTC on 18 January 2000 in the Tagish Lake area in northwestern British Columbia, Canada.
The Karoonda meteorite is a meteorite that fell to earth on 25 November 1930 at 10:53 pm near the South Australian town of Karoonda. It is of a rare composition, being carbonaceous chondrite, and is also rare in that it was found so soon after its landing. Several fragments are now held in the South Australian Museum in Adelaide.
The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After it broke up in the atmosphere, an extensive search for pieces was conducted and over 2 tonnes were recovered. The availability of large quantities of samples of the scientifically important chondrite class has enabled numerous investigations by many scientists; it is often described as "the best-studied meteorite in history." The Allende meteorite has abundant, large calcium–aluminum-rich inclusions (CAI), which are among the oldest objects formed in the Solar System.
Lost City is an unincorporated community and census-designated place (CDP) in Cherokee County, Oklahoma, United States. The population was 770 at the 2010 census, a 4.8 percent decline from the figure of 809 recorded in 2000. It was the site of the first meteorite fall in the US to be recorded by a camera network.
Pultusk is an H5 ordinary chondrite meteorite which fell on 30 January 1868 in Poland. The event has been known as the stony meteorite shower with the largest number of pieces yet recorded in history. Made up of rocky debris, it consists of pyroxene or olivine chondrules deployed in mass plagioclase, there being also kamacite.
Chergach is a meteorite found at southwest of El Mokhtar, Erg Chech, Timbuktu district, Mali. It fell on 2 or 3 July 2007, in daytime, and was composed of ordinary chondrite (H5).
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 Sutter's Mill meteorite is a carbonaceous chondrite which entered the Earth's atmosphere and broke up at about 07:51 Pacific Time on April 22, 2012, with fragments landing in the United States. The name comes from Sutter's Mill, a California Gold Rush site, near which some pieces were recovered. Meteor astronomer Peter Jenniskens assigned Sutter's Mill (SM) numbers to each meteorite, with the documented find location preserving information about where a given meteorite was located in the impacting meteoroid. As of May 2014, 79 fragments had been publicly documented with a find location. The largest (SM53) weighs 205 grams (7.2 oz), and the second largest (SM50) weighs 42 grams (1.5 oz).
The Itqiy meteorite is an enstatite-rich stony-iron meteorite. It is classified as an enstatite chondrite of the EH group that was nearly melted and is therefore very unusual for that group. Other classifications have been proposed and are an ongoing scientific debate.
On 13 October 1990, meteoroid EN131090, with an estimated mass of 44 kg, entered the Earth's atmosphere above Czechoslovakia and Poland and, after a few seconds, returned to space. Observations of such events are quite rare; this was the second recorded using scientific astronomical instruments and the first recorded from two distant positions, which enabled the calculation of several of its orbital characteristics. The encounter with Earth significantly changed its orbit and, to a smaller extent, some of its physical properties.
The Desert Fireball Network (DFN) is a network of cameras in Australia. It is designed to track meteoroids entering the atmosphere, and aid in recovering meteorites. It currently operates 50 autonomous cameras, spread across Western and South Australia, including Nullarbor plain, WA wheatbelt, and South Australian desert, covering an area of 2.5 million km2. The locations of the stations were chosen to facilitate meteorite searching. Starting in 2018, cameras deployed across the world began the first global fireball observatory in association with partner research teams.
Bunburra Rockhole is an anomalous basaltic achondritic meteorite. Originally classified as a eucrite, it was thought to belong to a group of meteorites that originated from the asteroid 4 Vesta, but has since been reclassified based on oxygen and chromium isotopic compositions. It was observed to fall on July 21, 2007, 04:43:56 local time, by the Desert Fireball Network (DFN). Two fragments weighing 150g and 174g were recovered by the DFN at 31°21.0′S, 129°11.4′E in the Nullarbor Desert region, South Australia in November of the same year. This is the first meteorite to be recovered using the Desert Fireball Network observatory.
Mason Gully is an ordinary chondrite of subclass H5, and is the second meteorite to be recovered using the Desert Fireball Network (DFN) camera observatory. One stone weighing 24.5g was observed to fall by the Desert Fireball Network observatory in Western Australia on 13 April 2010 at 10h36m10s UTC. It was recovered by the DFN on 3 November 2010 by Dr. R. Merle and the Fireball network recovery team, and was found 150m from its predicted fall location based upon the observed trajectory and calculated mass.
Dingle Dell is a 1.15 kg ordinary chondrite of subclass L/LL5, and the fourth meteorite to be recovered by the Desert Fireball Network camera observatory. It fell in the Morawa region of Western Australia on 31 October 2016 8:05 pm local time, and was recovered less than a week later, on the morning of 7 November, in a paddock at Dingle Dell farm. Given the rapid turnaround for meteorite recovery and a lack of rainfall between fall date and find date, the rock is in pristine condition and shows no evidence of terrestrial weathering (W0). This particular meteorite fall demonstrates the proficiency of the DFN as a sample recovery tool for meteoritics.
CM chondrites are a group of chondritic meteorites which resemble their type specimen, the Mighei meteorite. The CM is the most commonly recovered group of the 'carbonaceous chondrite' class of meteorites, though all are rarer in collections than ordinary chondrites.
Alais or Allais is the first carbonaceous chondrite meteorite identified. It fell near Alès in 1806 in multiple fragments which together weighed 6 kg, although only 0.26 kg (9.2 oz) remains. The meteorite contains a number of elements in similar proportions to the Solar System in its primordial state. It also contains organic compounds and water. It has proved to be one of the most important meteorites discovered in France.
The Winchcombe meteorite is a carbonaceous chondrite meteorite that was observed entering the Earth's atmosphere as a fluorescent green fireball over Gloucestershire, England, at 21:54 hours on 28 February 2021. Due to a public appeal, fragments were quickly recovered from the village of Winchcombe, enabling it to be collected for analysis before becoming degraded.
