Angra dos Reis meteorite
| Angra dos Reis | |
|---|---|
| Type | Achondrite |
| Group | Angrite |
| Composition | Fassaite(93%) |
| Country | Brazil |
| Region | Angra dos Reis |
| Coordinates | 22°58′S44°19′W/ 22.967°S 44.317°W |
| Observed fall | Yes |
| Fall date | 20 January 1869 |
| TKW | 1.5 kilograms (3.3 lb) |
TheAngra dos Reis meteoriteis the type specimen of theangritegroup. It was observed when it fell to earth in 1869.[1]
Discovery and naming
[edit]The meteorite is named afterAngra dos Reis,a municipality ofRio de Janeiro,Brazil.It fell on 20 January 1869 into the bay where the water was about 2 meters deep. Two fragments were found by a diver the next day.[2]
Museum
[edit]TheNational Museum of Brazilholds the meteorite as part of itsmeteorite collection.After the museum's 2018fire,there were concerns that it was lost in the rubble of the museum.[3][4]Some meteorites were found on October 19, 2018, including theAngra dos Reis.[5]
Mineralogy
[edit]Although it is the type specimen of theangrites,Angra dos Reis is actually very different from most other angrites. It consists almost entirely of a rare form ofpyroxenecalledfassaite.This makes it more like apyroxenitethan the typicalangrite,which is similar to abasalt.The only other meteorite samples that containfassaiteare thecalcium-aluminium-rich inclusionsfound in theAllende meteorite.The reason for this exotic composition is thought to be partial melting of a chondritic precursor under reduction-oxidation (redox) conditions in whichmeteoric ironis unstable.[6]
References
[edit]- ^"Angra dos Reis".Meteoritical Society.Retrieved3 January2013.
- ^"Angra dos Reis".Meteoritestudies.Retrieved3 January2013.
- ^"Meteorito de R$ 3 milhões segue perdido nos escombros do Museu Nacional"(in Portuguese). 25 September 2018.
- ^"O meteorito que vale R$ 3 milhões e está perdido nos escombros do Museu Nacional"(in Portuguese). 25 September 2018.
- ^"Meteorito que vale milhões de reais é recuperado dos escombros do Museu Nacional"(in Portuguese). 25 September 2018.
- ^"The Angrite Meteorite Mystery"(PDF).NASA.Archived fromthe original(PDF)on 2012-09-17.Retrieved2013-01-03.
