Glossary of meteoritics


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

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  • 2 Pallas – an asteroid from the asteroid belt and one of the likely parent bodies of the CR meteorites.
  • 4 Vesta – second-largest asteroid in the asteroid belt and likely source of the HED meteorites.
  • 221 Eos – an asteroid from the asteroid belt and one of the likely parent bodies of the CO meteorites.
  • 289 Nenetta – an asteroid from the asteroid belt and one of the likely parent bodies of the angrites.
  • 3103 Eger – an asteroid from the asteroid belt and one of the likely parent bodies of the aubrites.
  • 3819 Robinson – an asteroid from the asteroid belt and one of the likely parent bodies of the angrites.
  • 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.
  • Aerolite – an old term for stony meteorites.
  • ALH – an abbreviation used for meteorites from Allan Hills.
  • 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 – an obsolete classification of chondritic meteorites that are now classified as LL.
  • Angrite – a basaltic meteorite.
  • ANSMET – the Antarctic Search for Meteorites is a scientific program that looks for meteorites in the Transantarctic Mountains.
  • Asteroidal achondrite – an achondrite that differentiated on an asteroid or planetesimal
  • Asteroid spectral types – classification of asteroids according to their spectra.
  • Ataxite – an iron meteorite that has no visible structures when etched.
  • Aubrite – a class of achondrite meteorites composed primarily of the orthopyroxene enstatite

    B

  • Basaltic achondrite – a grouping of basalt meteorites
  • Brachinite – either a primitive achondrite or an asteroidal achondrite
  • Bolide – is an extremely bright meteor, especially one that explodes in the atmosphere

    C

  • C – can refer to carbonaceous chondrite or to an iron meteorite designation.
  • 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.
  • Class – two or more groups that have a similar chemistry and oxygen isotope ratios.
  • Compositional type – a classification based on overall composition, for example stony, iron, stony-iron. 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.
  • Cosmochemistry – the study of the chemical composition of the universe and its constituents, and the processes that produced those compositions.

    D

  • Dar al Gani – a meteorite field in the Libyan Sahara.
  • 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.
  • Differentiation – usually the process of a planetesimal forming an iron core and silicate mantle.
  • Duo – a grouping of two meteorites that share similar characteristics.

    E

  • E – can refer to enstatite chondrite or to an iron meteorite designation.
  • Eagle Station grouplet – a set of pallasite meteorite specimen that do not fit into any of the defined pallasite groups.
  • Electrophonic bolide – a meteoroid which produces a measurable discharge of electromagnetic energy during its passage through the atmosphere.
  • Enstatite achondrite – a meteorite that is mostly composed of enstatite. Usually part of the aubrite group.
  • Enstatite chondrite – a rare form of meteorite thought to comprise only 2% of chondrites.

    F

  • Fall – a meteorite that was seen while it fell to Earth and found.
  • Find – a meteorite that was found without seeing it fall.
  • Fossil meteorite – a meteorite that was buried under layers of sediment before the start of the Quaternary period. Some or all of the original cosmic material has been replaced by diagenetic minerals..
  • Fusion crust – a coating on meteorites that forms during their passage through the atmosphere.

    G

  • Group – a collection of five or more meteorites sharing similar characteristics.
  • Grouplet – a collection of fewer than five meteorites sharing similar characteristics.

    H

  • Hammer Stone – a specific individual meteorite that has hit either a human, man-made object, and/or an animal.
  • HED – abbreviation for three basaltic achondrite groups howardite, eucrite and diogenite.
  • HED meteorite – a clan of basaltic achondrites.
  • Hexahedrite – a structural class of iron meteorites having a relatively low nickel content
  • Hunter – a person who searches 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.
  • Insoluble organic matter – Kerogen-like macromolecule residue from carbonaceous chondrite meteorites after soluble organic matter has been removed.
  • Iron–nickel alloy – an alternative expression for meteoric iron.
  • Iron meteorite – a meteorite that is mainly composed of meteoric iron.

    K

  • Kakangari chondrite – a group of chondrite meteorites.
  • Kamacite – a native metal 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. Compare :Category:Meteorites found on bodies other than Earth.
  • Lunar meteorite – a meteorite that originated from the Moon. 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 meteorite
  • Martian meteorite – a meteorite that originated from Mars. Compare :Category:Meteorites found on bodies other than Earth.
  • Maskelynite – a natural glass found in meteorites.
  • Matrix – the mineral assemblage surrounding chondrules.
  • Mesosiderite – a grouping of stony-iron meteorite that are breccias.
  • Meteoric iron – a native metal found in meteorites and a mixture of different mineral phases. Compare telluric iron.
  • Meteorite Observation and Recovery Program – a scientific program that was centered in Canada.
  • Meteoriticist – a scientist working on meteorites, meteors, and meteoroids.
  • Meteoritics – the science of meteorites, meteors, and meteoroids.
  • MORP – abbreviation for Meteorite Observation and Recovery Program.
  • Micrometeorite – microscopic meteorites derived from Cosmic dust.

    N

  • Nakhlite – a group of Martian meteorites
  • Neumann lines – a pattern of fine parallel lines seen in some iron meteorites, thought to be due to impact events on the parent body
  • Nonmagmatic meteorite – iron meteorites that were thought to have not formed by igneous processes.

    O

  • O – usually refers to ordinary chondrite
  • Observed fall – a meteorite that was seen when it fell to Earth.
  • Octahedrite – the most common structural class of iron meteorites.
  • Ordinary chondrite – a chondrite meteorite, where 'ordinary' means that it is the most common found

    P

  • PAC – abbreviation for primitive achondrite.
  • Pallasite – a class of stony–iron meteorite.
  • Panspermia – the hypothesis that life could reach other planets by the means of meteorites and/or comets.
  • Parent body – the celestial body from which originates a meteorite or a class of meteorites.
  • Petrologic type – a classification scheme that expresses the degree to which a meteorite has been affected by the secondary processes of thermal metamorphism and aqueous alteration on the parent asteroid.
  • 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.
  • Plessite – a fine grained intergrowth found in meteoric iron consisting of kamacite, taenite and tetrataenite lamella.
  • Presolar grains – interstellar solid matter in the form of tiny solid grains from a time before the Sun was formed.
  • Primitive meteorite
  • Primitive achondrite – a meteorite that has similarities to achondrites and chondrites.
  • Protoplanetary disk – a circumstellar disk from which all solids in the Solar System formed.
  • '''Pyroxene pallasite grouplet'''