Ureilite
Encyclopedia
Ureilite is a rare type of stony meteorite
that has a unique mineralogical composition very different from that of other stony meteorites. This dark grey or brownish meteorite type is named after the village Novy Urey (Cyrillic: Новый Урей), Mordovia
Republic of Russia
, where a meteorite of this type fell on 4 September 1886. Notable ureilites are the Novo Urei and the Goalpara, also named for the town in which it landed (Goalpara
, Assam
India
). On 7 October 2008, tiny asteroid 2008 TC3
entered Earth's atmosphere and exploded an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. Fragments of this asteroid were recovered the following December and were found to be ureilite.
Scientists have discovered amino acids, the building blocks of life in this meteorite 2008 TC3
where none were expected taking into account the high temperatures reached in the explosion about 1000 °C.
-pigeonite
achondrite
. Compared to most other meteorites, ureilites tend to have a high percentage of carbon (average 3% by weight) in the form of graphite and nanodiamonds. The diamonds, which are rarely more than a few micrometres in diameter, are probably the result of high pressure shockwaves produced by collisions of the ureilite parent body with other asteroid
s. Ureilites can be divided into two subcategories: monomict and polymict. Monomict ureilites are coarse grained with olivine
usually more abundant than pyroxene
. Polymict ureilites are a mixture of clasts of dissimilar composition.
, Moon
, 4 Vesta
), but there has been no parent body found as yet for the ureilites. Prior to impacting Earth, 2008 TC3
was identified as an F-type asteroid
.
Scientists have discovered amino acids, the building blocks of life in a ureilite meteorite
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
that has a unique mineralogical composition very different from that of other stony meteorites. This dark grey or brownish meteorite type is named after the village Novy Urey (Cyrillic: Новый Урей), Mordovia
Mordovia
The Republic of Mordovia , also known as Mordvinia, is a federal subject of Russia . Its capital is the city of Saransk. Population: -Geography:The republic is located in the eastern part of the East European Plain of Russia...
Republic of Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, where a meteorite of this type fell on 4 September 1886. Notable ureilites are the Novo Urei and the Goalpara, also named for the town in which it landed (Goalpara
Goalpara
Goalpara is the district headquarter of Goalpara district, Assam, India. It is situated west of Guwahati.-Etymology:The name of Goalpara is said to have originally derived from `Gwaltippika` meaning `Guwali village` or the village of the milk men. In the local dialect "para" means...
, Assam
Assam
Assam , also, rarely, Assam Valley and formerly the Assam Province , is a northeastern state of India and is one of the most culturally and geographically distinct regions of the country...
India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
). On 7 October 2008, tiny asteroid 2008 TC3
2008 TC3
thumb|right|300px|Ground path of the meteoroid; red line is the path, terminating where it would have hit the ground; green line is the infrasound detection of the explosion; orange crosshairs show METEOSAT IR fireball location; predicted altitudes are listed; exact path and fireball altitude not...
entered Earth's atmosphere and exploded an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. Fragments of this asteroid were recovered the following December and were found to be ureilite.
Scientists have discovered amino acids, the building blocks of life in this meteorite 2008 TC3
2008 TC3
thumb|right|300px|Ground path of the meteoroid; red line is the path, terminating where it would have hit the ground; green line is the infrasound detection of the explosion; orange crosshairs show METEOSAT IR fireball location; predicted altitudes are listed; exact path and fireball altitude not...
where none were expected taking into account the high temperatures reached in the explosion about 1000 °C.
Composition
A technical name for ureilite would be olivineOlivine
The mineral olivine is a magnesium iron silicate with the formula 2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface....
-pigeonite
Pigeonite
Pigeonite is a mineral in the clinopyroxene group. It has a general formula of Si2O6. The calcium cation fraction can vary from 5% to 25%, with iron and magnesium making up the rest of the cations....
achondrite
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies...
. Compared to most other meteorites, ureilites tend to have a high percentage of carbon (average 3% by weight) in the form of graphite and nanodiamonds. The diamonds, which are rarely more than a few micrometres in diameter, are probably the result of high pressure shockwaves produced by collisions of the ureilite parent body with other asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s. Ureilites can be divided into two subcategories: monomict and polymict. Monomict ureilites are coarse grained with olivine
Olivine
The mineral olivine is a magnesium iron silicate with the formula 2SiO4. It is a common mineral in the Earth's subsurface but weathers quickly on the surface....
usually more abundant than pyroxene
Pyroxene
The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They share a common structure consisting of single chains of silica tetrahedra and they crystallize in the monoclinic and orthorhombic systems...
. Polymict ureilites are a mixture of clasts of dissimilar composition.
Origin
Unknown. Some groups of meteorites come from a single object (ie. MarsMars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
, Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, 4 Vesta
4 Vesta
Vesta, formally designated 4 Vesta, is one of the largest asteroids, with a mean diameter of about . It was discovered by Heinrich Wilhelm Olbers on March 29, 1807, and is named after the Roman virgin goddess of home and hearth, Vesta....
), but there has been no parent body found as yet for the ureilites. Prior to impacting Earth, 2008 TC3
2008 TC3
thumb|right|300px|Ground path of the meteoroid; red line is the path, terminating where it would have hit the ground; green line is the infrasound detection of the explosion; orange crosshairs show METEOSAT IR fireball location; predicted altitudes are listed; exact path and fireball altitude not...
was identified as an F-type asteroid
F-type asteroid
F-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group.-Characteristics:Generally similar to the B-type asteroids, but...
.
Scientists have discovered amino acids, the building blocks of life in a ureilite meteorite