| Muonionalusta meteorite | |
|---|---|
 The Muonionalusta meteorite, on loan to thePrague National Museum in 2010. It is the largest meteorite ever exhibited in the Czech Republic. | |
| Type | IVA (Of) |
| Structural classification | Fine Octahedrite |
| Class | Octahedrite |
| Group | Iron |
| Composition | Ni, Ga, Ge |
| Country | Sweden |
| Region | Norrbotten |
| Coordinates | 67°48′N23°6.8′E / 67.800°N 23.1133°E /67.800; 23.1133 |
| Observed fall | No |
| Found date | 1906 |
| Strewn field | Yes |
 Related media on Wikimedia Commons | |
TheMuonionalusta meteorite (Finnish pronunciation:[ˈmuo̯nionˌɑlustɑ],Swedish pronunciation:[mʉˈǒːnɪɔnalːɵsta])[1] is ameteorite classified as fineoctahedrite, type IVA (Of) which impacted in northernScandinavia, west of the border betweenSweden andFinland, about one million years BCE.
The first fragment of the Muonionalusta meteorite was found in 1906 near the village of Kitkiöjärvi.[2] Around forty pieces are known today, some being quite large. Other fragments have been found in a 25-by-15-kilometre (15.5 mi × 9.3 mi) area in thePajala district ofNorrbotten County, approximately 140 kilometres (87 mi) north of theArctic Circle.
The meteorite was first described in 1910 by Professor A. G. Högbom, who named it after the nearby place Muonionalusta on theMuonio River. It was studied in 1948 by ProfessorNils Göran David Malmqvist.[3] The Muonionalusta meteorite, probably the oldest known meteorite (4.5653 ± 0.0001 billion years),[4] marks the first occurrence ofstishovite in an iron meteorite.
The mineral muonionalustaite, a hydrated nickel chloride, was first found as a weathering product from a meteorite sample.[5]
The nameMuonionalusta is Finnish: it comes from the name Muonio (+ possessive particle-(o)n-) andalusta, which in this context means "a place below", i.e. downstream fromMuonio.
Studies have shown it to be the oldest discovered meteorite impacting the Earth during theQuaternary Period, about one million years ago. It is quite clearly part of the iron core or mantle of a planetoid, which shattered into many pieces upon its fall on our planet.[6] Since landing on Earth the meteorite has experienced four ice ages. It was unearthed from a glacial moraine in the northerntundra. It has a strongly weathered surface covered with cemented faceted pebbles.
New analysis of this strongly shock-metamorphosed iron meteorite has shown a content of 8.4%nickel and trace amounts of rare elements—0.33 ppmgallium, 0.133 ppmgermanium and 1.6 ppmiridium. It also contains the mineralschromite,daubréelite,schreibersite,akaganéite and inclusions oftroilite.[3] For the first time, analysis has proved the presence of a form ofquartz altered by extremely high pressure—stishovite,[3] probably a pseudomorphosis aftertridymite. From the article "First discovery of stishovite in an iron meteorite":[2]
Stishovite, a high pressure polymorph of SiO2, is an exceptionally rare mineral...and has only been found in association with a few meteorite impact structures.... Clearly, the meteoritic stishovite cannot have formed by isostatic pressure prevailing in the core of the parent asteroid.... One can safely assume then that stishovite formation(in the Muonionalusta meteorite) is connected with an impact event. The glass component might have formed directly as a shock melt....
A 2010 study reported the lead isotope dating in the Muonionalusta meteorite and concluded the stishovite was from an impact event hundreds of millions of years ago: "The presence of stishovite signifies that this meteorite was heavily shocked, possibly during the 0.4 Ga [billion years] old breakup event indicated by cosmic ray exposure...."[4]
Fragments of the Muonionalusta meteorite are held by numerous institutions around the world.
A part of the meteorite is used in the 25-pieces limited Rolls-Royce Tranquility Collection (Phantom VIII) Controller[8] and in theM850i xDrive Coupé Night Sky Edition by BMW.[9][10]
Luxury watch brands likeRolex,Omega,Jaeger-LeCoultre,Parmigiani Fleurier, andJacob & Co. have used Muonionalusta meteorite dials in exclusive timepieces. The meteorite’s uniqueWidmanstatten patterns add a cosmic touch to high-end watch designs.[11]
In 2021,Poland's Germania Mint released anumismatic coin namedImpact Moments: Meteorite that depicts the extinction ofdinosaurs as a result of a meteorite hitting the earth. Each coin has a fragment of the Muonionalusta meteorite embedded in it.[12]