Ureilites are a rare type of stone meteorites , which has a unique mineralogical composition, very different from other stone meteorites. Such dark gray or brownish meteorites are named after the village of Novy Urey ( Mordovia , Russia ), where a meteorite of this type fell on September 4, 1886.
In addition to Novo Urei, Goalpara also refers to the ureilites (named after the Indian city of Goalpara, where it fell). On October 7, 2008, a small (3-5 m in size) meteoroid “ 2008 TC 3 ” entered the Earth’s atmosphere and exploded at an altitude of 37 km (23 miles) above the Nubian Desert in Sudan . Fragments of this meteoroid were discovered in December of the same year and were recognized as urelites. Researchers found amino acids in the substance of the 2008 TC 3 meteoroid, the building blocks of life that survived despite the high temperature that rose as a result of the explosion to 1000 ° C. [one]
Composition
The technical name of the ureilites is olivine- pajonite achondrite . Compared to most other meteorites, ureilitites typically have a high percentage of carbon (an average of 3% by weight) in the form of graphite and nanodiamonds . [2] Diamonds, which are rarely larger than a few micrometers in diameter, are likely the result of high-pressure shock waves produced by the collision of the parent body with other asteroids. Ureilites can be divided into two subcategories: monomict and polymict. Coarse-grained monomict ureylites with a usually higher olivine content than pyroxene . Polymict Ureilitas are a mixture of clusters of heterogeneous composition.
Origin
The origin of the ureilites is reliably unknown. Some groups of meteorites come from the same object (that is, Mars , the Moon , (4) Vesta ), but so far it has not been possible to find the parent body for the urelites. Before falling to Earth, “ 2008 TC 3 ” was identified as a Class F asteroid . [3]
According to one theory, urelites were formed inside the parent body with cumulative crystals that form into crystalline layers. In favor of this theory is the fact that in some ureilites the grains are aligned in the preferred orientation. Another suggestion is that urelites are the remainder of molten materials. Other theories claim that ureilites are unprocessed material that has never melted, or that they are mixtures of carbon chondrite and basaltic rock melts. It remains unclear whether ureilitis occurred on different parent bodies or in different regions of the same body. The presence of diamonds, which can form from graphite as a result of heavy impact metamorphism, hints at the history of a strong impact [4] . In contrast, a 2018 study of diamond inclusions in the 2008 TC 3 showed that they could only form for a relatively long period of time at very high pressure, assuming that “the urelite’s parent body was a protoplanet the size of Mercury to Mars” [5 ] .
See also
- Meteorite classification
- Glossary of meteorites
Notes
- ↑ Life's Building Blocks Found on Surprising Meteorite . Space.com . Date of treatment May 10, 2016.
- ↑ Norton, O. Richard. The Cambridge Encyclopedia of Meteorites : [] . - Cambridge University Press, 2002-03-11. - ISBN 9780521621434 .
- ↑ P. Jenniskens et al. The impact and recovery of asteroid 2008 TC3 (Eng.) // Nature : journal. - 2009 .-- 26 March ( vol. 458 , no. 7237, number 458 ). - P. 485-488 . - DOI : 10.1038 / nature07920 . - . - PMID 19325630 . Archived June 1, 2009. Published in Letters to Nature.
- ↑ ureilite . www.daviddarling.info . Date of treatment May 10, 2016.
- ↑ Nabiei, Farhang; Badro, James; Dennenwaldt, Teresa; Oveisi, Emad; Cantoni, Marco; Hébert, Cécile; El Goresy, Ahmed; Barrat, Jean-Alix; Gillet, Philippe. A large planetary body inferred from diamond inclusions in a ureilite meteorite (Eng.) // Nature Communications : journal. - Nature Publishing Group , 2018. - Vol. 9 , no. 1 . - ISSN 2041-1723 . - DOI : 10.1038 / s41467-018-03808-6 .