Howardites
Topic

#Iron meteorites

Meteorites made of nickel-iron metal from the cores of shattered asteroids.

Lessons (9)

  • Early Solar System chronologyMeteorites let us build a timeline of the first few million years of the Solar System with a precision that seems almost impossible. Here is
  • Falls and findsEvery meteorite is either a fall or a find. Knowing the difference helps explain why museums value some meteorites so highly.
  • Iron meteorite groupsStructure tells you what an iron meteorite looks like when etched, but chemistry tells you which parent body it came from. Here you will lea
  • Iron meteorites: cores, cooling and dynamosIron meteorites preserve quantitative records of how asteroid cores crystallised and cooled, and even whether they generated magnetic fields
  • Iron meteorites and their hidden patternsIron meteorites are pieces of the metal cores of shattered asteroids. Cut one open and etch it, and many reveal a beautiful crystal pattern
  • Stony-irons: pallasites and mesosideritesStony-iron meteorites are rare mixtures of metal and rock. They include some of the most beautiful objects that fall from the sky.
  • The classification frameworkMeteorite classification is a hierarchy built on petrology, bulk chemistry and isotopes.
  • The NC–CC isotopic dichotomyNucleosynthetic isotope anomalies split meteorites into two great families that formed in separate regions of the disc.
  • Three kinds of meteoriteMeteorites come in three big families: stony, iron and stony-iron. Each one tells a different story about the asteroid it came from.

Courses (10)

  • The metallurgy of iron meteoritesIron meteorites are pieces of asteroid cores that cooled over millions of years. Their crystal structures and nickel distributions record co
  • How meteorites are classifiedTens of thousands of meteorites are sorted into a system of classes and groups. This lesson explains the main branches and what the labels o
  • Worlds that meltedSome early asteroids melted and separated into core, mantle and crust, then were shattered.
  • Adult course: Meteorites from first principlesTwelve lessons for adult learners: where meteorites come from, how falls are tracked and recovered, how they are classified and dated, what
  • Metals from spaceIron meteorites are natural alloys of iron and nickel. Their structure, strength and crystal patterns show metallic bonding and slow cooling
  • Rock or metal?Some meteorites are made of rock. Some are made of metal. Some are a mix of both. Let's sort them!
  • Three kinds of meteoriteScientists sort meteorites into three main kinds by what they are made of: stone, iron, or a mixture of both.
  • Density: a test you can measureMeteorites are usually denser than Earth rocks of the same size. In this lesson you will calculate density, measure volume by displacement a
  • Elements, compounds and mixtures in meteoritesMeteorites are made of the same chemical elements as Earth, combined in the same ways.
  • Inside a planet: cores, mantles and crustsNobody can drill to Earth's core, but meteorites let us hold pieces of the cores, mantles and crusts of other worlds.

Books (5)

  • Meteorite Classification: The Professional's GuideA working reference for classifiers, curators and postgraduate researchers. It sets out current practice for every meteorite type: the fifte
  • The Meteorite Collector's HandbookA meteorite collection can hold pieces of asteroids, Vesta, the Moon and Mars. This handbook explains every major class, from ordinary chond
  • Meteorites ExplainedThe oldest solids in meteorites formed 4,567 million years ago, before any planet. Meteorites Explained shows how scientists know: from the
  • Meteoritics for StudentsMeteorites are the oldest rocks we can hold, and reading them uses nuclear physics, chemistry, geology and orbital mechanics. This guide run
  • My First Book of MeteoritesA shooting star is a speck of dust burning up 100 kilometres above the ground. This book explains what meteors, meteorites, asteroids and co

Famous meteorites (11)

  • BacubiritoA long, heavy iron from the mountains of north-western Mexico, now displayed at a science centre in Culiacán.
  • Campo del CieloA field of small craters in northern Argentina, where more than 100 tonnes of iron fell from the sky about four thousand years ago.
  • Canyon DiabloThe iron that made Meteor Crater in Arizona – and helped scientists measure the age of the Earth.
  • Cape YorkFor centuries the Inuit of north-west Greenland made blades from a meteorite – until an explorer shipped it to New York.
  • GibeonA prehistoric shower of iron across southern Namibia, whose crystal patterns now gleam on watch faces and rings.
  • HobaThe heaviest known meteorite on Earth has never been moved from the spot where it landed.
  • MundrabillaTwo giant iron masses found on Australia's Nullarbor Plain in 1966, packed with unusual sulphide nodules.
  • MuonionalustaAn iron meteorite from Arctic Sweden that fell long before the last ice age – and was carried by glaciers before anyone found it.
  • SeymchanFound in a stream in Russia's Far East in 1967 and thought to be an ordinary iron – until pieces with gem-like crystals turned up decade
  • Sikhote-AlinIn 1947 an iron meteoroid shattered over the Russian Far East, raining tonnes of metal and blasting more than 100 craters.
  • WillametteAmerica's largest meteorite was secretly hauled through a forest by a settler – and is sacred to the people who knew it first.

Meteorite types (26)

  • Asteroidal achondritesFully melted, differentiated rocks from the crusts and mantles of asteroids, Vesta above all.
  • Eagle Station pallasitesA tiny grouplet of pallasites with iron-rich olivine and nickel-rich metal, from a separate parent body.
  • H chondritesHigh-iron ordinary chondrites: about a third of all meteorites seen to fall. H chondrites have the highest total iron of the ordinary chondr
  • IAB ironsIrons with stony inclusions, from a partly melted asteroid. Canyon Diablo and Campo del Cielo.
  • IC ironsA small magmatic group of coarse octahedrites, low in nickel. IC irons are a small group, mostly coarse octahedrites or coarser, with about
  • IIAB ironsHexahedrites and coarsest octahedrites, including Sikhote-Alin. The IIAB irons have the lowest nickel of the major groups, about 5.3–6.4%.
  • IIC ironsA rare group of plessitic octahedrites. IIC irons are plessitic octahedrites with about 9–11.5% nickel. Only a few are known.
  • IID ironsFine to medium octahedrites rich in gallium and germanium. IID irons are fine to medium octahedrites with about 10–11% nickel and high galli
  • IIE ironsIrons full of silicate fragments, possibly from asteroid Hebe. IIE irons are octahedrites of varying coarseness that often contain silicate
  • IIF ironsA small group of magmatic irons. IIF is a small magmatic group of irons with distinctive trace-element patterns. Only a handful are known.
  • IIG ironsLow-nickel irons with large crystals of schreibersite. IIG irons are coarse, low-nickel irons containing large amounts of schreibersite, an
  • IIIAB ironsThe most common iron meteorites: medium octahedrites from one asteroid core. IIIAB is the largest group of irons, about a third of all irons
  • IIIE ironsCoarse octahedrites, separated from IIIAB by their chemistry. IIIE irons are coarse octahedrites with about 8–9% nickel.
  • IIIF ironsA small group with very low gallium and germanium. IIIF irons are medium to coarse octahedrites with about 7–8% nickel and very low gallium
  • Iron meteoritesAlmost pure iron-nickel metal, mostly from the cores of asteroids that melted and were later shattered.
  • IVA ironsFine octahedrites, including the famous Gibeon. IVA irons are fine octahedrites with about 7.5–9.5% nickel and very low gallium and germaniu
  • IVB ironsNickel-rich ataxites. Hoba, the largest meteorite, is one. IVB irons are ataxites with about 16% to 18% nickel and very high iridium.
  • Main-group pallasitesNine in ten pallasites: magnesium-rich olivine in metal related to the IIIAB irons.
  • Ordinary chondritesThe everyday meteorite: four in every five falls. Three groups, H, L and LL, from at least three asteroids.
  • PallasitesGem-like olivine crystals set in iron-nickel metal. Pallasites contain large olive-green crystals of olivine embedded in iron-nickel metal.
  • Primitive achondritesRocks that began to melt but were never fully processed: halfway between chondrites and igneous rocks.
  • Pyroxene and ungrouped pallasitesPallasites that fit neither main group nor Eagle Station, among them the pyroxene-bearing pair Vermillion and Yamato 8451.
  • Stony-iron meteoritesRoughly equal parts metal and silicate. Rare, and among the most beautiful meteorites.
  • Stony meteoritesMeteorites made mostly of silicate minerals. They are by far the most common kind seen to fall.
  • Ungrouped ironsIrons that fit no known group: each may represent its own asteroid. About 15% of iron meteorites do not belong to any recognised group.
  • WinonaitesPrimitive achondrites related to the silicate inclusions in IAB irons. Named after the Winona meteorite, found buried in a Sinagua ruin in A

Space missions (3)

  • CuriosityA car-sized laboratory exploring an ancient lake bed, and finding iron meteorites on the way.
  • OpportunityThe rover that found the first meteorite ever identified on another planet. Opportunity and its twin, Spirit, were golf-cart-sized rovers de
  • PsycheThe first visit to a world rich in metal, which may be the exposed core of a shattered planet.

Meteorite minerals (23)

  • AkaganéiteA chlorine-bearing rust that makes iron meteorites flake and crumble in museum drawers.
  • BrezinaiteA chromium sulphide found only in meteorites. Brezinaite is a sulphide of chromium alone.
  • BrianiteA sodium calcium magnesium phosphate found in silicate inclusions of an iron meteorite. Brianite is a phosphate rich in sodium.
  • BuchwalditeA sodium calcium phosphate found in the troilite nodules of the Cape York iron. Buchwaldite is a simple phosphate of sodium and calcium.
  • CarlsbergiteChromium nitride, tiny plates found in the metal of iron meteorites. Carlsbergite is a nitride of chromium.
  • ChladniiteA sodium calcium magnesium phosphate named after the founder of meteorite science.
  • CoheniteAn iron–nickel carbide found in many iron meteorites, the natural cousin of cementite in steel. Cohenite is a carbide: iron and nickel combi
  • DaubréeliteA black iron chromium sulphide that forms lamellae inside troilite in iron meteorites.
  • ElaliiteAn iron phosphate oxide first found in the El Ali iron meteorite from Somalia. Elaliite is an iron oxide that also contains a phosphate grou
  • ElkinstantoniteAn iron phosphate oxide from the El Ali iron meteorite, named after the leader of the Psyche mission.
  • GraphiteSoft, layered carbon, found as nodules in iron meteorites, in ureilites and in primitive chondrites.
  • HaxoniteA nickel-rich iron carbide found in iron meteorites and some chondrites. Haxonite is a carbide containing more nickel and less carbon than c
  • KamaciteLow-nickel iron metal, the main mineral of most iron meteorites and the metal flecks in chondrites.
  • KosmochlorA green sodium chromium pyroxene first found in an iron meteorite and later in Burmese jade.
  • KrinoviteA green sodium chromium silicate found only in the graphite nodules of iron meteorites.
  • OlseniteA potassium iron phosphate from the El Ali iron meteorite. Olsenite is a phosphate of potassium and iron.
  • PanethiteA sodium magnesium phosphate found with brianite in the Dayton iron. Panethite is a phosphate of sodium, calcium, magnesium and iron, closel
  • PlessiteA fine-grained intergrowth of kamacite and taenite that fills the spaces in the Widmanstätten pattern.
  • SchreibersiteAn iron–nickel phosphide found in almost all iron meteorites, and a possible source of phosphorus for early life.
  • TaeniteNickel-rich iron metal, which forms the thin bright ribbons of the Widmanstätten pattern.
  • TetrataeniteAn ordered iron–nickel alloy that forms only with extremely slow cooling, and a natural rare-earth-free magnet.
  • TroiliteIron sulphide, the bronze mineral found in almost every meteorite. Troilite is iron sulphide with exactly one iron atom for every sulphur at
  • YagiiteAn osumilite-group silicate found in the silicate inclusions of a IIE iron meteorite.

Glossary (56)

Questions and answers (39)

Impact craters (10)

  • BoxholeBoxhole is a small, well-preserved meteorite crater in the Northern Territory of Australia, about 180 km north-east of Alice Springs.
  • HenburyThe Henbury craters lie in the red desert of the Northern Territory, about 130 km south-west of Alice Springs.
  • KaaliKaali, on the Estonian island of Saaremaa in the Baltic Sea, is one of the few meteorite craters that probably formed while people were livi
  • KamilKamil Crater, in the remote south-western corner of Egypt, is one of the freshest-looking impact craters on Earth.
  • MonturaquiMonturaqui is a small meteorite crater in one of the driest places on Earth, the Atacama Desert of northern Chile.
  • MoraskoMorasko, on the northern outskirts of the city of Poznań in western Poland, is one of the few meteorite crater fields in Europe and the only
  • OdessaThe Odessa crater, in west Texas in the United States, is a small impact crater about 168 m across made by an iron meteorite.
  • Sikhote-AlinOn the morning of 12 February 1947 one of the largest meteorite falls in recorded history struck the Sikhote-Alin mountains in the far east
  • VeeversVeevers is a small, beautifully preserved meteorite crater about 70 to 80 m across in the Gibson Desert of Western Australia.
  • WhitecourtThe Whitecourt crater, in the forests of west-central Alberta, is one of the smallest and youngest meteorite craters known in Canada.

Impact events (3)

  • HenburyA dozen craters from one shattered iron, remembered in local tradition. In the red country of central Australia lies a group of about a doze
  • Meteor Crater (Barringer Crater)The first crater on Earth shown to have been made by an impact. Meteor Crater is a bowl about 1.2 km across and 170 m deep in the desert of
  • Sterlitamak, 1990An iron meteorite that dug a crater in a farm field. Late one May night in 1990, a fireball lit up the sky over Bashkortostan in the souther

Asteroids (1)

  • PsychePsyche stands out among the large asteroids because it appears to be rich in metal.

Myths and folklore (3)

People (11)

  • Albert FooteThe Philadelphia mineral dealer who in 1891 first described the iron meteorites around Meteor Crater and the diamonds inside them. Albert E.
  • Alois von Beckh-WidmanstättenThe Viennese scientist whose name was given to the criss-cross crystal pattern seen inside iron meteorites.
  • Aristides BrezinaThe Vienna curator whose detailed classification of meteorites was used around the world for more than half a century.
  • Carl von SchreibersThe director of the imperial natural history collections in Vienna, who built one of the world's first great meteorite collections.
  • Henry Clifton SorbyThe Sheffield scientist who invented the study of rocks in thin slices and described chondrules as frozen drops of fiery rain.
  • Jacobus Hermanus BritsThe farmer whose plough struck the Hoba iron in 1920, the largest single meteorite known.
  • John WassonThe UCLA chemist who sorted iron meteorites into chemical groups using nickel, gallium, germanium and iridium.
  • Robert PearyThe Arctic explorer who took the great Cape York iron meteorites from Greenland to New York in the 1890s.
  • Roy ClarkeThe Smithsonian curator who helped collect and describe the Allende meteorite in 1969 and co-discovered the mineral tetrataenite. Roy S. Cla
  • Vagn BuchwaldThe Danish metallurgist whose three-volume handbook described almost every iron meteorite known, and who recovered the Agpalilik iron from G
  • William ThomsonThe English mineralogist in Naples who first saw the crystal pattern inside an iron meteorite, in 1804.

Britain and Ireland (1)

  • The Rowton meteoriteThe only iron meteorite ever seen to fall in Britain, dug from a Shropshire field with a walking stick.

Museums and collections (8)

Hunting and collecting (2)

  • Caring for meteoritesHow to store, handle and display meteorites: why irons rust and weep, lawrencite, safe humidity levels, desiccants, storage materials and fr
  • Meteor-wrongs: the rocks that fool peopleHow to tell a meteorite from slag, magnetite, hematite, basalt, concretions, industrial iron, chert, obsidian and other look-alikes, with si

Meteorites (the 60 largest of 1,072)