Glossary of meteoritics

This is a glossary of terms used in Meteoritics, the science of meteorites.

#

• 289 Nenetta - an asteroid from the asteroid belt and one of the likely parent bodies of the angrites.
• 3819 Robinson - an asteroid from the asteroid belt and one of the likely parent bodies of the angrites.
• 4 Vesta - second largest asteroid in the asteroid belt and likely source of the HED meteorites.
• IA meteorite - an iron meteorite group now part of the IAB group/complex.
• IAB meteorite - an iron meteorite and primitive achondrite of the IAB group/complex.
• IB meteorite - an iron meteorite group now part of the IAB group/complex.
• IC meteorite - an iron meteorite that is part of the IC group.

A

• Ablation - the process of a meteorite losing mass during the passage through the atmosphere.
• Acapulcoite - a group of primitive achondrites.
• Accretion - the process in which matter of the protoplanetary disk coalesces to form planetesimals.
• Achondrite - a differentiated meteorite (meaning without chondrules).
• Aerolite - an old term for stony meteorites.
• ALH - an abbreviation used for meteorites from Allan Hills.
• Allan Hills - a mountain chain in Antarctica where meteorites are concentrated by ice movements and can be easily spotted in the snow.
• Allan Hills 84001 - is an exotic meteorite from Mars that does not fit into any of the SNC groups and was thought to contain evidence for life on Mars.
• Allende meteorite - is the largest carbonaceous chondrite ever found on Earth.
• Amphoterite
• Angrite - a basaltic meteorite.
• Anomalous - meteorites that have properties that are unusual for their group or grouplet.
• ANSMET - the ANtarctic Search for METeorites is scientific program that looks for meteorites in the Transantarctic Mountains.
• Asteroidal achondrite - an achondrite that differentiated on an asteroid or planetesimal (see planetary achondrite)
• Asteroid spectral types - classification of asteroids according to their spectra.
• Aristides Brezina - a meteoriticist.
• Ataxite - an iron meteorite that has no visible structures when etched.

B

• Basaltic achondrite - a grouping of basalt meteorites (HED meteorites + Angrite)
• Brachinite

C

• C - can refer to carbonaceous chondrite or to an iron meteorite designation (roman numeral and letter).
• Carbonaceous chondrite
• CAI - an abbreviation of Calcium-aluminium-rich inclusion
• Calcium-aluminium-rich inclusion
• Chassignite
• Chondrite - stony meteorites unmodified by melting or differentiation of the parent body
• Chondrule - millimetre-scale round grains found in chondrites
• Clan - meteorites that are not similar enough to form a group, but are also not too different from each other to be put in separate classes.^[1]
• Class - two or more groups that have a similar chemistry and oxygen isotope ratios.^[1]
• Compositional type - a classification based on overall composition, for example stony, iron, stony-iron (as introduced by Maskelyne). Can also refer to the composition deduced from spectroscopy of asteroids.
• Condensation - the process of chemicals changing from the gaseous to the solid phase during the cooling of the protoplanetary disk.
• Condensation sequence - the sequence of minerals that changes from the gaseous to the solid state while the protoplanetary disk cools.
• Cosmic dust - small interplanetary and interstellar particles that are similar to meteorites (See Micrometeorite).
• Cosmochemistry - the science of the chemistry of the Solar System, which is based in part on the chemistry of meteorites.

D

• Dar al Gani
• 'Desert glass' - natural glass found in deserts formed from the silica in sand as a result of lightning strikes or meteor impacts.
• Differentiated - a meteorite that has undergone igneous differentiation. (See: achondrite)
• Differentiation - usually the process of a planetesimal forming an iron core and silicate mantle.
• Duo - a grouping of two meteorites that share similar characteristics (see Grouplet).

E

• E - can refer to enstatite chondrite or to an iron meteorite designation (roman numeral and letter).
• Eagle Station grouplet
• Enstatite achondrite - a meteorite that is mostly composed of enstatite. Usually part of the aubrite group.
• Enstatite chondrite

F

• Fall - a meteorite that was seen while it fell to Earth and found.
• Find - a meteorite that was found without seeing it fall.
• Fragment - a part of a meteorite that broke during passage through the atmosphere.
• Fragmentation - the process in which a meteorite breaks while falling through the atmosphere.
• Fusion crust - a coating of meteorites that forms during their passage through the atmosphere.

G

• Group - a collection of more than 5 meteorites sharing similar characteristics.^[1]
• Grouplet - a collection of less than 5 meteorites sharing similar characteristics.^[1]
• Gustav Rose - a meteoriticist.
• Gustav Tschermak - a meteoriticist.

H

• HED - abbreviation for three basaltic achondrite groups howardite, eucrite and diogenite.
• HED meteorite - a clan of basaltic achondrites.
• Hexahedrite
• Hunter - a person that is searching for meteorites.

I

• Impact breccia - rock composed of fragments of terrestrial, extraterrestrial or mixed origin fused by the energy of impact
• Impactite - informal term for a terrestrial rock resulting from the shocking impact of a meteor.
• Iron-nickel alloy - an alternative expression for meteoric iron.
• Iron meteorite - a meteorite that is mainly composed of meteoric iron.

J

K

• Kakangari chondrite - a group of chondrite meteorites.
• Kamacite - a native metal (mineral) found in meteorites.

L

• Lodranite - member of a small group of primitive achondrites thought to derive from deeper within the same parent body as acapulcoites
• Lunaite - a meteorite that originated from the moon (synonym of Lunar meteorite). Compare Category:Meteorites found on bodies other than Earth.
• Lunar meteorite - a meteorite that originated from the Moon (synonym of Lunaite). Compare Category:Meteorites found on bodies other than Earth.

M

• Main group pallasite - a pallasite belonging to the main group.
• Main mass - the largest/heaviest piece of a fragmented meteorite, typically found in a strewn field.
• Magmatic - igneous, that is, solidified magma or produced by magma
• Magmatic meteorite
• Martian meteorite - a meteorite that originated from Mars. Compare Category:Meteorites found on bodies other than Earth.
• Maskelynite - a natural glas found in meteorites.
• Matrix - the mineral assemblage surrounding chondrules.
• Mesosiderite - a grouping of stony-iron meteorite that are breccias.
• Meteor - a object passing through Earth's atmosphere emitting light.
• Meteoric iron - a native metal found in meteorites and a mixture of different mineral phases. Compare telluric iron.
• Meteoroid - a natural object in space no larger than 1 meter.
• Meteorite - a rock found on the Earth's surface that did not form on Earth.
• Meteorite Observation and Recovery Program - a scientific program that was centered in Canada.
• Meteoriticist - a scientist working on meteorites.
• Meteoritics - the science of meteorites.
• MORP - abbreviation for Meteorite Observation and Recovery Program.
• Micrometeorite - microscopic meteorites derived from Cosmic dust.

N

• Nakhlite
• Neumann lines (or Neumann bands) - a pattern of fine parallel lines seen in some iron meteorites, thought to be due to impact events on the parent body
• Nevil Story-Maskelyne - a meteoriticist.
• Nonmagmatic meteorite
• Northwest Africa - a popular meteorite find location.
• NWA - abbreviation of northwest Africa.

O

• O - usually refers to ordinary chondrite
• Observed fall - a meteorite that was seen when it fell to Earth.
• Octahedrite
• Ordinary chondrite - a chondrite meteorite, where 'ordinary' means that it is the most common found
• Oriented - ?, eg Photo: An oriented specimen of the <name> meteorite.

P

• PAC - abbreviation for primitive achondrite.
• Pallasite

• Panspermia - the theory that life could reach other planets by the means of meteorites and/or comets.
• Parent body
• Petrologic type
• Pitts grouplet - a grouplet of meteorites that is part of the IAB meteorites
• Planetary achondrite - an achondrite that was differentiated on a planet and not a planetesimal or asteroid (See asteroidal achondrite).^[2]
• Plessite - a fine grained intergrowth found in meteoric iron consisting of kamacite, taenite and tetrataenite lamella.^[3]
• Presolar grains
• Primitive meteorite
• Primitive achondrite - a meteorite that has similarities with achondrites and chondrites.
• Pristine - extent of a meteorite shock stage and weathering.
• Protoplanetary disk - a cicumstellar disk from which all solids in the Solar System formed.
• Pyroxene pallasite grouplet

Q

• QUE - abbreviation for Queen Alexandra Range.
• Queen Alexandra Range - a mountain range in eastern Antarctica where many meteorites are found.

R

Regmaglypts on Sikhote Alin

• Regmaglypts - thumb print sized indentations in the surface of larger meteorites formed by ablation as the meteorite passes through a planet's atmosphere, probably caused by vortices of hot gas.^[4]
• Refractory elements - chemical elements that have high boiling and condensation temperatures.
• Rose-Tschermak-Brezina classification - a classification developed by Gustav Rose, Gustav Tschermak and Aristides Brezina.
• Rumurati chondrite - a group of chondrites.

S

• Shergottite
• Shock stage
• Shock metamorphism
• Siderite - the old term for iron meteorite.
• Siderolite - the old term for stony-iron meteorites.
• SNC - abbreviation for shergottite, nakhlite and chassignite, the three martian meteorites.
• Solar nebula - a synonym of the protoplanetary disk.
• Spectral class -
• Stony meteorite - a meteorite composed mostly of silicates.
• Stony-iron meteorite - a meteorite that is a mixture of meteoric iron and silicates.
• Strewn field - a field of fragments from one meteorite fall.
• Structural class - a subdivision of iron meteorites in ataxites, hexahedrites and octahedrites.

T

• Taenite - a native metal (mineral) found in meteorites.
• Tamdakht
• Total known weight (TKW) - total known mass of a meteorite.
• Trio - a grouping of three meteorites that share similar characteristics (see Grouplet).
• Tunguska event - an air burst of a meteorite that caused major destruction.
• Type - subdivision of meteorites. Loosely defined. Usually refers to chondrite, achondrite and sometimes primitive achondrite.^[1]

U

• Udei Station grouplet - a grouplet of meteorites that is part of the IAB meteorites.
• Ungrouped - a meteorite that has not been assigned to a group or grouplet.
• Undifferentiated
• Ureilite

V

• Vesta - second largest asteroid in the asteroid belt and likely source of the HED meteorites.
• Volatile elements - are chemical elements that have low boiling and condensation temperatures.

W

• Weathering - the terrestrial alteration of a meteorite.
• Widmanstätten pattern - a fine interleaving of kamacite and taenite bands/ribbons found in octahedrite irons and some pallasites.
• Winonaite
• Weston meteorite - The Weston meteorite is a meteorite which fell to earth above the town of Weston, Connecticut on December 14, 1807.^[5]

X

Y

• YA - abbreviation for Yamato Mountains.
• Yamato Mountains - a group of mountains in Antarctica where many meteorites are found.

Z

References