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.
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.
Campo del Cielo refers to a group of iron meteorites and the area in Argentina where they were found. The site straddles the provinces of Chaco and Santiago del Estero, located 1,000 kilometers (620 mi) north-northwest of Buenos Aires, Argentina and approximately 500 kilometres (310 mi) southwest of Asunción, Paraguay. The crater field covers 18.5 by 3 kilometres and contains at least 26 craters, the largest being 115 by 91 metres.
A mantle is a layer inside a planetary body bounded below by a core and above by a crust. Mantles are made of rock or ices, and are generally the largest and most massive layer of the planetary body. Mantles are characteristic of planetary bodies that have undergone differentiation by density. All terrestrial planets, a number of asteroids, and some planetary moons have mantles.
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 Willamette Meteorite, officially named Willamette and originally known as Tomanowos by the Clackamas Chinook Native American tribe, is an iron-nickel meteorite found in the U.S. state of Oregon. It is the largest meteorite found in the United States and the sixth largest in the world. There was no impact crater at the discovery site; researchers believe the meteorite landed in what is now Canada or Montana, and was transported as a glacial erratic to the Willamette Valley during the Missoula Floods at the end of the last Ice Age. It has long been held sacred by indigenous peoples of the Willamette Valley, including the federally recognized Confederated Tribes of the Grand Ronde Community of Oregon (CTGRC).
The Cape York meteorite, also known as the Innaanganeq meteorite, is one of the largest known iron meteorites, classified as a medium octahedrite in chemical group IIIAB. In addition to many small fragments, at least eight large fragments with a total mass of 58 tonnes have been recovered, the largest weighing 31 tonnes. The meteorite is named after the location where the largest fragment was found: 23 miles (37 km) east of Cape York, in Savissivik, Meteorite Island, Greenland.
Moon rock or lunar rock is rock originating from Earth's Moon. This includes lunar material collected during the course of human exploration of the Moon, and rock that has been ejected naturally from the Moon's surface and landed on Earth as meteorites.
The Hoba meteorite is named after the farm Hoba West, where it lies, not far from Grootfontein, in the Otjozondjupa Region of Namibia. It has been uncovered, but because of its large mass, has never been moved from where it fell. The main mass is estimated at more than 60 tonnes. It is the largest known intact meteorite and about twice as massive as the largest fragment of either the Cape York meteorite's 31-tonne Ahnighito kept in the American Museum of Natural History or the Campo del Cielo's 31-tonne Gancedo in Argentina. It is also the most massive naturally occurring piece of iron known on Earth's surface. The name "Hoba" comes from a Khoekhoegowab word meaning "gift". Following its donation to the government in 1987, a visitor centre was constructed with a circular stone access and seating area.
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.
A meteorite fall, also called an observed fall, is a meteorite collected after its fall from outer space was observed by people or automated devices. Any other meteorite is called a "find". There are more than 1,300 documented falls listed in widely used databases, most of which have specimens in modern collections. As of February 2023, the Meteoritical Bulletin Database had 1372 confirmed falls.
The Sylacauga meteorite fell on November 30, 1954, at 12:46 local time in Oak Grove, Alabama, near Sylacauga, in the United States. It is also commonly called the Hodges meteorite because a fragment of it struck Ann Elizabeth Fowler Hodges (1920–1972).
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 Novato meteorite is an ordinary chondrite which entered the earth's atmosphere and broke up over Northern California at 19:44 Pacific Time on 17 October 2012. The falling bolide created a bright fireball and sonic booms and fragmented into smaller pieces as the intense friction of passing through the atmosphere heated it and absorbed its kinetic energy. The meteoroid was about 35 centimeters (14 in) across.
The Mundrabilla meteorite is an iron meteorite found in 1911 in Australia, one of the largest meteorites found, with a total known weight of 22 tonnes and the main mass accounting for 12.4 tonnes.
The Chelyabinsk meteor was a superbolide that entered Earth's atmosphere over the southern Ural region in Russia on 15 February 2013 at about 09:20 YEKT. It was caused by an approximately 18 m (59 ft) diameter, 9,100-tonne (10,000-short-ton) near-Earth asteroid that entered the atmosphere at a shallow 18.3 ± 0.4 degree angle with a speed relative to Earth of 19.16 ± 0.15 kilometres per second. The light from the meteor was briefly brighter than the Sun, visible as far as 100 km (60 mi) away. It was observed in a wide area of the region and in neighbouring republics. Some eyewitnesses also reported feeling intense heat from the fireball.
The Chelyabinsk meteorite is the fragmented remains of the large Chelyabinsk meteor of 15 February 2013 which reached the ground after the meteor's passage through the atmosphere. The descent of the meteor, visible as a brilliant superbolide in the morning sky, caused a series of shock waves that shattered windows, damaged approximately 7,200 buildings and left 1,491 people injured. The resulting fragments were scattered over a wide area.
The Gancedo Meteorite is the largest known fragment of the meteor shower that fell in Campo del Cielo, in Charata, Chaco Province, Argentina.
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.
