Carbonaceous chondrite

Last updated
Carbonaceous chondrite
—  Class  —
Allende meteorite.jpg
A slice of the Allende meteorite showing circular chondrules.
Type Chondrite
Alternative namesC chondrites

Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 8 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites. The C chondrites represent only a small proportion (4.6%) [1] of meteorite falls.

Contents

Some famous carbonaceous chondrites are: Allende, Murchison, Orgueil, Ivuna, Murray, Tagish Lake, Sutter's Mill and Winchcombe.

General description

C chondrites contain a relatively high proportion of carbon (up to 3%), which is in the form of graphite, carbonates and organic compounds, including amino acids. In addition, they contain water and minerals that have been modified by the influence of water. [2]

The carbonaceous chondrites were not exposed to higher temperatures, so that they are hardly changed by thermal processes. Some carbonaceous chondrites, such as the Allende meteorite, contain calcium-aluminum-rich inclusions (CAIs). These are compounds that emerged early from the primeval solar nebula, condensed out and represent the oldest minerals formed in the Solar System. [3] [4]

Some primitive carbonaceous chondrites, such as the CM chondrite Murchison, contain presolar minerals, including moissanite (natural silicon carbide) and tiny nanometer-sized diamonds that apparently were not formed in our solar system. These presolar minerals were probably formed during the explosion of a nearby supernova or in the vicinity of a pulsating red giant (more precisely: a so-called AGB star) before they got into the cloud of matter from which the Solar System was formed. Such star explosions release pressure waves that can condense clouds of matter in their surroundings, leading to the formation of new ones, stars and planetary systems. [5]

Another carbonaceous chondrite, the Flensburg meteorite (2019), provides evidence of the earliest known occurrence of liquid water in the young Solar System to date. [6] [7]

Composition and classification

Some carbonaceous chondrites. From left to right: Allende, Yukon and Murchison. Carbonaceous chondrites.jpg
Some carbonaceous chondrites. From left to right: Allende, Yukon and Murchison.

Carbonaceous chondrites are grouped according to distinctive compositions thought to reflect the type of parent body from which they originated. These C chondrite groups are now each named with a standard two-letter CX designation, where C stands for "carbonaceous" (other types of chondrites do not begin with this letter) plus a capital letter in the spot X, which is very often the first letter of the name of a prominent meteorite—often the first to be discovered—in the group. Such meteorites are often named for the place where they fell, thus giving no clue as to the physical nature of the group. Group CH, where H is for "high metal" is so far the only exception. See below for name derivations of each group.

Several groups of carbonaceous chondrites, notably the CM and CI groups, contain high percentages (3% to 22%) of water, [8] as well as organic compounds. They are composed mainly of silicates, oxides and sulfides, with the minerals olivine and serpentine being characteristic. The presence of volatile organic chemicals and water indicates that they have not undergone significant heating (>200 °C) since they were formed, and their compositions are considered to be close to that of the solar nebula from which the Solar System condensed. Other groups of C chondrites, e.g., CO, CV, and CK chondrites, are relatively poor in volatile compounds, and some of these have experienced significant heating on their parent asteroids.

CI group

This group, named after the Ivuna meteorite (Tanzania), have chemical compositions that are close to that measured in the solar photosphere (aside from gaseous elements, and elements such as lithium which are underrepresented in the Sun's photosphere by comparison to their abundance in CI chondrites). In this sense, they are chemically the most primitive known meteorites. [ citation needed ]

CI chondrites typically contain a high proportion of water (up to 22%), [8] and organic matter in the form of amino acids [9] and PAHs. [10] Aqueous alteration promotes a composition of hydrous phyllosilicates, magnetite, and olivine crystals occurring in a black matrix, and a possible lack of chondrules. It is thought they have not been heated above 50 °C (122 °F), indicating that they condensed in the cooler outer portion of the solar nebula.

Five CI chondrites have been observed to fall: Ivuna, Orgueil, Alais, Tonk, and Revelstoke. Four others have been found by Japanese field parties in Antarctica. In general, the extreme fragility of CI chondrites causes them to be highly susceptible to terrestrial weathering, and they do not survive on Earth's surface for long after they fall.

CV group

NWA 3118, CV3 NWA 3118 meteorite.jpg
NWA 3118, CV3

This group takes its name from Vigarano (Italy). Most of these chondrites belong to the petrologic type 3.

CV chondrites observed falls:

CM group

The group takes its name from Mighei (Ukraine), but the most famous member is the extensively studied Murchison meteorite. Many falls of this type have been observed and CM chondrites are known to contain a rich mix of complex organic compounds such as amino-acids and purine/pyrimidine nucleobases. [11] [12] [13] CM chondrite famous falls:

CR group

The group takes its name from Renazzo (Italy). The best parent body candidate is 2 Pallas. [11]

CR chondrites observed falls:

Other famous CR chondrites:

CH group

"H" stands for "high metal" because CH chondrites may contain up to as much as 40% of metal. [16] That makes them one of the most metal-rich of any of the chondrite groups, second only to the CB chondrites and some ungrouped chondrites such as NWA 12273. The first meteorite discovered was ALH 85085. Chemically, these chondrites are closely related to CR and CB groups. All specimens of this group belong only to petrologic types 2 or 3. [11]

CB group

Gujba meteorite, a bencubbinite found in Nigeria. Polished slice, 4.6 x 3.8 cm. Note the nickel-iron chondrules, which have been age-dated to 4.5627 billion years. Gujba meteorite, bencubbinite (14785860604).jpg
Gujba meteorite, a bencubbinite found in Nigeria. Polished slice, 4.6 × 3.8 cm. Note the nickel-iron chondrules, which have been age-dated to 4.5627 billion years.

The group takes its name from the most representative member: Bencubbin (Australia). Although these chondrites contain over 50% nickel-iron metal, they are not classified as mesosiderites because their mineralogical and chemical properties are strongly associated with CR chondrites. [11]

CK group

This group takes its name from Karoonda (Australia). These chondrites are closely related to the CO and CV groups. [11]

CO group

The group takes its name from Ornans (France). The chondrule size is only about 0.15 mm on average. They are all of petrologic type 3.

Famous CO chondrite falls:

Famous finds:

CL group

Officially recognized in 2022 [17] after minimum specimens (five) described. [18] CL chondrites, named after type specimen(s) Loongana, are chondrite-rich, metal-rich, and volatile-poor.

C ungrouped

The most famous members:

Organic matter

Murchison meteorite Murchison crop.jpg
Murchison meteorite

Most of the organic carbon in CI and CM carbonaceous chondrites is an insoluble complex material. That is similar to the description for kerogen. A kerogen-like material is also in the ALH84001 Martian meteorite (an achondrite).

The CM meteorite Murchison has over 96 extraterrestrial amino acids and other compounds including carboxylic acids, hydroxy carboxylic acids, sulphonic and phosphonic acids, aliphatic, aromatic and polar hydrocarbons, fullerenes, heterocycles, carbonyl compounds, alcohols, amines and amides.

Extraterrestrial amino acids

Amino acids in carbonaceous chondrites have important implications for theories describing the delivery of organic compounds to the early Earth and the subsequent development of life. Shortly after its fall and recovery in Australia in 1969, the Murchison meteorite was found to host five protein amino acids (glycine, alanine, valine, proline, and glutamic acid) in addition to 12 non-proteinogenic amino acids including α-aminoisobutyric acid and isovaline, which are rare on Earth. [19] Since then, the number of characterized amino acids in the Murchison meteorite has risen to 96, including 12 of the 20 common biological amino acids, along with hundreds more that have been detected, but remain uncharacterized. [20] While the abundance of amino acids present in terrestrial soils presents a potential source of contamination, most of the amino acids characterized in Murchison are terrestrially rare or absent. [21]

Amino acids may be structurally chiral, meaning that they have two possible non-superimposable mirror image structures, termed enantiomers. Conventionally, these are referred to as left-handed (L) and right-handed (D) by analogy with glyceraldehyde. Living beings use L-amino acids, although there is no apparent reason why one enantiomer is favoured over the other as they behave equivalently in biological systems. [22] In contrast with terrestrial biology, early laboratory studies, including the famous Miller-Urey Experiment, have shown that amino acids may form under a range of possible abiotic conditions with equal (racemic) mixtures of D- and L-enantiomers. [23] Thus, the ratios between enantiomers for a given amino acid may discriminate between biotic and abiotic formation mechanisms. In the first characterization of amino acids in Murchison, all chiral examples were present in racemic mixtures indicating an abiotic origin. [19] This is consistent with proposed sythetic pathways, as the formation of isovaline and other α-dialkyl amino acids in CM chondrites has been attributed to the Strecker synthesis which produces racemic mixtures of enantiomers. [24]

The Strecker synthesis of alpha amino acids from carbonyl compounds in the presence of ammonia and cyanide. Strecker-Synthese Ubersicht V3.svg
The Strecker synthesis of alpha amino acids from carbonyl compounds in the presence of ammonia and cyanide.

Ehrenfreund et al. (2001) [9] found that amino acids in CI chondrites Ivuna and Orgueil were present at much lower concentrations than in CM chondrites (~30%), and that they had a distinct composition high in β-alanine, glycine, γ-ABA, and β-ABA but low in α-aminoisobutyric acid (AIB) and isovaline. This implies that they had formed by a different synthetic pathway, and on a different parent body from the CM chondrites.

Enantiomeric excesses observed in extraterrestrial amino acids

More recently, amino acids from several carbonaceous chondrites have been identified with significant L-enantiomeric excesses. L-excesses from 3 – 15% in several non-protein α-dialkyl amino acids have been found in the Murchison and Murray meteorites. [25] Their extraterrestrial origin is indicated by their absence in biological systems and significant heavy isotope enrichments in 13C and deuterium compared to terrestrial values. [26] Further characterization of L-isovaline excesses up to 20.5% in a range of carbonaceous chondrite groups have supported a hypothesis that increasing hydrothermal alteration of the host meteorite correlates with increasing observed L-enantiomeric excess. [27] Large L-excesses for α-H amino acids have also been reported, but these are more problematic due to the potential for terrestrial contamination. [28] The ungrouped C2 chondrite Tagish Lake has L-aspartic acid excesses up to ~60%, with carbon isotope measurements indicating an extraterrestrial origin due to significant enrichments in 13C. [29] In Tagish Lake, proteinogenic amino acids show both significant L-excesses, and racemic mixtures: glutamic acid, serine, and threonine were found to have ~50 – 99% L-excesses, while alanine was racemic. [29]

It has been proposed that extraterrestrial amino acid L-excesses observed in carbonaceous chondrites are a result of differences in the crystallization behaviour of the enantiomers. [30] Circularly polarized ultraviolet light has been shown to generate L-excesses in crystallizing amino acids for experimental conditions mimicking alteration on asteroids, and this is thought to be the dominant extraterrestrial source of chiral symmetry breaking (i.e., the favouring of one enantiomer over another). [31] It is notable that only excesses of the L-enantiomer have been observed in extraterrestrial amino acids, suggesting that the abiotic process responsible for enantiomeric enrichments may be the original source of the L-amino acid selectivity currently observed in terrestrial life.

Implications for extraterrestrial biosignatures

NASA have proposed a “Ladder of Life Detection” threshold of >20% enantiomeric excess in amino acids to distinguish extraterrestrial biosignatures. But, as previously mentioned, recent studies of carbonaceous chondrites and complementary experimental investigations have demonstrated that even larger enantiomeric excesses may be produced by abiotic pathways. To identify chiral asymmetry (enantiomeric excess) of biological origin, Glavin et al. (2020) [30] emphasize three criteria that must be met: chiral asymmetry, light 13C isotopic composition, and simplified distribution of structural isomers. If a distribution of amino acids in an extraterrestrial sample is found to be chirally asymmetric, display structural isomeric preference, and carry 13C, 15N, and D depletions relative to associated inorganic material, a compelling case may be made for its biological origin. With the current interest in sample return missions from carbonaceous asteroids (e.g., OSIRIS-REx) and Mars headed by NASA and other space agencies , the subsequent analysis of returned samples devoid of terrestrial contamination will provide the best opportunity to discover potential biosignatures in our Solar System.

See also

Related Research Articles

<span class="mw-page-title-main">Miller–Urey experiment</span> Experiment testing the origin of life

The Miller–Urey experiment (or Miller experiment) was an experiment in chemical synthesis carried out in 1952 that simulated the conditions thought at the time to be present in the atmosphere of the early, prebiotic Earth. It is seen as one of the first successful experiments demonstrating the synthesis of organic compounds from inorganic constituents in an origin of life scenario. The experiment used methane (CH4), ammonia (NH3), hydrogen (H2), in ratio 2:2:1, and water (H2O). Applying an electric arc (the latter simulating lightning) resulted in the production of amino acids.

<span class="mw-page-title-main">Xanthine</span> Chemical compound

Xanthine is a purine base found in most human body tissues and fluids, as well as in other organisms. Several stimulants are derived from xanthine, including caffeine, theophylline, and theobromine.

<span class="mw-page-title-main">Cosmochemistry</span> Study of the chemical composition of matter in the universe

Cosmochemistry or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. This is done primarily through the study of the chemical composition of meteorites and other physical samples. Given that the asteroid parent bodies of meteorites were some of the first solid material to condense from the early solar nebula, cosmochemists are generally, but not exclusively, concerned with the objects contained within the Solar System.

<span class="mw-page-title-main">Chondrite</span> Class of stony meteorites made of round grains

A chondrite is a stony (non-metallic) meteorite that has not been modified, by either melting or differentiation of the parent body. They are formed when various types of dust and small grains in the early Solar System accreted to form primitive asteroids. Some such bodies that are captured in the planet's gravity well become the most common type of meteorite by arriving on a trajectory toward the planet's surface. Estimates for their contribution to the total meteorite population vary between 85.7% and 86.2%.

<span class="mw-page-title-main">Chirality (chemistry)</span> Geometric property of some molecules and ions

In chemistry, a molecule or ion is called chiral if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational changes. This geometric property is called chirality. The terms are derived from Ancient Greek χείρ (cheir) 'hand'; which is the canonical example of an object with this property.

<span class="mw-page-title-main">Micrometeorite</span> Meteoroid that survives Earths atmosphere

A micrometeorite is a micrometeoroid that has survived entry through the Earth's atmosphere. Usually found on Earth's surface, micrometeorites differ from meteorites in that they are smaller in size, more abundant, and different in composition. The IAU officially defines meteoroids as 30 micrometers to 1 meter; micrometeorites are the small end of the range (~submillimeter). They are a subset of cosmic dust, which also includes the smaller interplanetary dust particles (IDPs).

<span class="mw-page-title-main">Orgueil (meteorite)</span> Meteorite found in France

Orgueil is a scientifically important carbonaceous chondrite meteorite that fell in southwestern France in 1864.

<span class="mw-page-title-main">Murchison meteorite</span> Meteorite found in Victoria, Australia

The Murchison meteorite is a meteorite that fell in Australia in 1969 near Murchison, Victoria. It belongs to the carbonaceous chondrite class, a group of meteorites rich in organic compounds. Due to its mass and the fact that it was an observed fall, the Murchison meteorite is one of the most studied of all meteorites.

Homochirality is a uniformity of chirality, or handedness. Objects are chiral when they cannot be superposed on their mirror images. For example, the left and right hands of a human are approximately mirror images of each other but are not their own mirror images, so they are chiral. In biology, 19 of the 20 natural amino acids are homochiral, being L-chiral (left-handed), while sugars are D-chiral (right-handed). Homochirality can also refer to enantiopure substances in which all the constituents are the same enantiomer, but some sources discourage this use of the term.

<span class="mw-page-title-main">Tagish Lake (meteorite)</span> Stony meteorite

The Tagish Lake meteorite fell at 16:43 UTC on 18 January 2000 in the Tagish Lake area in northwestern British Columbia, Canada.

<span class="mw-page-title-main">Ronald Breslow</span> American chemist

Ronald Charles David Breslow was an American chemist from Rahway, New Jersey. He was University Professor at Columbia University, where he was based in the Department of Chemistry and affiliated with the Departments of Biological Sciences and Pharmacology; he had also been on the faculty of its Department of Chemical Engineering. He had taught at Columbia since 1956 and was a former chair of the university's chemistry department.

<span class="mw-page-title-main">Allende meteorite</span> CV3 carbonaceous chondrite meteorite

The Allende meteorite is the largest carbonaceous chondrite ever found on Earth. The fireball was witnessed at 01:05 on February 8, 1969, falling over the Mexican state of Chihuahua. After it broke up in the atmosphere, an extensive search for pieces was conducted and over 2 tonnes were recovered. The availability of large quantities of samples of the scientifically important chondrite class has enabled numerous investigations by many scientists; it is often described as "the best-studied meteorite in history." The Allende meteorite has abundant, large calcium–aluminium-rich inclusions (CAI), which are among the oldest objects formed in the Solar System.

<span class="mw-page-title-main">Isovaline</span> Chemical compound

Isovaline is a rare amino acid transported to Earth by the Murchison meteorite, which landed in Australia in 1969. The discovery of isovaline in the biosphere demonstrates an extraterrestrial origin of amino acids and has been linked to the homochirality of life on Earth, suggesting a role in the origin of life.

CI chondrites, also called C1 chondrites or Ivuna-type carbonaceous chondrites, are a group of rare carbonaceous chondrite, a type of stony meteorite. They are named after the Ivuna meteorite, the type specimen. CI chondrites have been recovered in France, Canada, India, and Tanzania. Their overall chemical composition closely resembles the elemental composition of the Sun, more so than any other type of meteorite.

Zita Carla Torrão Pinto Martins, OSE, is a Portuguese astrobiologist, and an associate professor at Instituto Superior Técnico. She was a Royal Society University Research Fellow (URF) at Imperial College London. Her research explores how life may have begun on Earth by looking for organic compounds in meteorite samples.

<span class="mw-page-title-main">Sandra Pizzarello</span> Italian biochemist

Sandra Pizzarello, D.Bi.Sc. was a Venetian biochemist known for her co-discovery of amino acid enantiomeric excess in carbonaceous chondrite meteorites. Her research interests concerned the characterization of meteoritic organic compounds in elucidating the evolution of planetary homochirality. Pizzarello was a project collaborator and co-investigator for the NASA Astrobiology Institute (NAI), the president of the International Society for the Study of the Origin of Life (2014-2017), and an emerita professor at Arizona State University (ASU).

Asteroidal water is water or water precursor deposits such as hydroxide (OH−) that exist in asteroids. The "snow line" of the Solar System lies outside of the main asteroid belt, and the majority of water is expected in minor planets. Nevertheless, a significant amount of water is also found inside the snow line, including in near-earth objects (NEOs).

Pseudo-panspermia is a well-supported hypothesis for a stage in the origin of life. The theory first asserts that many of the small organic molecules used for life originated in space. It continues that these organic molecules were distributed to planetary surfaces, where life then emerged on Earth and perhaps on other planets. Pseudo-panspermia differs from the fringe theory of panspermia, which asserts that life arrived on Earth from distant planets.

CM chondrites are a group of chondritic meteorites which resemble their type specimen, the Mighei meteorite. The CM is the most commonly recovered group of the 'carbonaceous chondrite' class of meteorites, though all are rarer in collections than ordinary chondrites.

<span class="mw-page-title-main">Alais meteorite</span> Meteorite found in France

Alais or Allais is the first carbonaceous chondrite meteorite identified. It fell near Alès in 1806 in multiple fragments which together weighed 6 kg, although only 0.26 kg (9.2 oz) remains. The meteorite contains a number of elements in similar proportions to the Solar System in its primordial state. It also contains organic compounds and water. It has proved to be one of the most important meteorites discovered in France.

References

  1. ↑ Bischoff, A.; Geiger, T. (1995). "Meteorites for the Sahara: Find locations, shock classification, degree of weathering and pairing". Meteoritics. 30 (1): 113–122. Bibcode:1995Metic..30..113B. doi: 10.1111/j.1945-5100.1995.tb01219.x . ISSN   0026-1114.
  2. ↑ BÜHLER: . Springer-Verlag, 2013, ISBN   978-3-0348-6667-5 , pp. 130 ( limited preview in Google Books search).
  3. ↑ Horst Rauchfuss:. Springer-Verlag, 2006, ISBN   978-3-540-27666-1 , pp. 83 ( limited preview in Google Books search).
  4. ↑ Gregor Markl: . Springer-Verlag, 2014, ISBN   978-3-662-44628-7 , pp. 420 ( limited preview in Google Book Search).
  5. ↑ Martin Vieweg: Ancient carbonates are evidence of water, on: Wissenschaft.de from January 22, 2021 The oldest carbonates in the solar system , on: EurekAlert! from January 20, 2021
  6. ↑ Addi Bischof et al.: The old, unique C1 chondrite Flensburg – Insight into the first processes of aqueous alteration, brecciation, and the diversity of water-bearing parent bodies and lithologies . In: Geochimica et Cosmochimica Acta, Vol. 293, 15 January 2021, pages 142-186
  7. ↑ Robert Hutchison: Cambridge University Press, 2006, ISBN   978-0-521-03539-2, pp. 42 (limited preview in Google Books search).
  8. 1 2 Norton, O. Richard (2002). The Cambridge Encyclopedia of Meteorites. Cambridge: Cambridge University Press. pp. 121–124. ISBN   978-0-521-62143-4.
  9. 1 2 Ehrenfreund, Pascale; Daniel P. Glavin; Oliver Botta; George Cooper; Jeffrey L. Bada (2001). "Extraterrestrial amino acids in Orgueil and Ivuna: Tracing the parent body of CI type carbonaceous chondrites". Proceedings of the National Academy of Sciences. 98 (5): 2138–2141. Bibcode:2001PNAS...98.2138E. doi: 10.1073/pnas.051502898 . PMC   30105 . PMID   11226205.
  10. ↑ Wing, Michael R.; Jeffrey L. Bada (1992). "The origin of the polycyclic aromatic hydrocarbons in meteorites". Origins of Life and Evolution of the Biosphere. 21 (5–6): 375–383. Bibcode:1991OLEB...21..375W. doi:10.1007/BF01808308. S2CID   11504324.
  11. 1 2 3 4 5 "Carbonaceous chondrite" Meteorite.fr: All About Meteorites: Classification Archived 2009-10-12 at the Wayback Machine
  12. ↑ Nemiroff, R.; Bonnell, J., eds. (28 April 2012). "Sutter's Mill Meteorite". Astronomy Picture of the Day . NASA . Retrieved 2012-05-06.
  13. ↑ Pearce, Ben K. D.; Pudritz, Ralph E. (2015). "Seeding the Pregenetic Earth: Meteoritic Abundances of Nucleobases and Potential Reaction Pathways". Astrophysical Journal. 807 (1): 85. arXiv: 1505.01465 . Bibcode:2015ApJ...807...85P. doi:10.1088/0004-637X/807/1/85. S2CID   93561811.
  14. ↑ "Meteoritical Bulletin: Entry for Aguas Zarcas". www.lpi.usra.edu. Retrieved 2020-08-21.
  15. ↑ https://www.science.org/content/article/unusual-meteorite-more-valuable-gold-may-hold-building-blocks-life
  16. ↑ Norton, O. Richard (2002). The Cambridge Encyclopedia of Meteorites. Cambridge: Cambridge University Press. p. 139. ISBN   978-0-521-62143-4.
  17. ↑ Gattacceca, Jérôme; McCubbin F. M.; Grossman J.; Bouvier A.; Chabot N. L.; D'Orazio M.; Goodrich C.; Greshake A.; Gross J.; Komatsu M.; Miao B.; Schrader D. (2022). "The Meteoritical Bulletin, No. 110" (PDF). Meteoritics and Planetary Science. 57 (11): 21022105. Bibcode:2022M&PS...57.2102G. doi:10.1111/maps.13918. hdl:11568/1160522. S2CID   253089085.
  18. ↑ Metzler, K.; Hezel, D. C.; Barosch, J.; Wölfer, E.; Schneider, J. M.; Hellmann, J. L.; Berndt, J.; et al. (2021). "The Loongana (CL) Group of Carbonaceous Chondrites" (PDF). Geochimica et Cosmochimica Acta. 304: 1–31. Bibcode:2021GeCoA.304....1M. doi:10.1016/j.gca.2021.04.007. S2CID   234847404.
  19. 1 2 Kvenvolden, Keith; Lawless, James; Pering, Katherine; Peterson, Etta; Flores, Jose; Ponnamperuma, Cyril; Kaplan, I. R.; Moore, Carleton (1970). "Evidence for Extraterrestrial Amino-acids and Hydrocarbons in the Murchison Meteorite". Nature. 228 (5275): 923–926. Bibcode:1970Natur.228..923K. doi:10.1038/228923a0. ISSN   1476-4687. PMID   5482102. S2CID   4147981.
  20. ↑ Glavin, Daniel P.; Alexander, Conel M. O'D.; Aponte, José C.; Dworkin, Jason P.; Elsila, Jamie E.; Yabuta, Hikaru (2018-01-01), Abreu, Neyda (ed.), "Chapter 3 - The Origin and Evolution of Organic Matter in Carbonaceous Chondrites and Links to Their Parent Bodies", Primitive Meteorites and Asteroids, Elsevier, pp. 205–271, doi:10.1016/b978-0-12-813325-5.00003-3, hdl: 2060/20180004493 , ISBN   978-0-12-813325-5 , retrieved 2023-05-01
  21. ↑ Cronin, John R.; Chang, Sherwood (1993), Greenberg, J. M.; Mendoza-Gómez, C. X.; Pirronello, V. (eds.), "Organic Matter in Meteorites: Molecular and Isotopic Analyses of the Murchison Meteorite", The Chemistry of Life's Origins, 416, Dordrecht: Springer Netherlands: 209–258, Bibcode:1993ASIC..416..209C, doi:10.1007/978-94-011-1936-8_9, ISBN   978-94-011-1936-8 , retrieved 2023-05-01
  22. ↑ Milton, R. C. deL.; Milton, S. C. F.; Kent, S. B. H. (1992-06-05). "Total Chemical Synthesis of a D-Enzyme: The Enantiomers of HIV-1 Protease Show Reciprocal Chiral Substrate Specificity". Science. 256 (5062): 1445–1448. doi:10.1126/science.1604320. ISSN   0036-8075. PMID   1604320.
  23. ↑ Miller, Stanley L. (1953-05-15). "A Production of Amino Acids Under Possible Primitive Earth Conditions". Science. 117 (3046): 528–529. Bibcode:1953Sci...117..528M. doi:10.1126/science.117.3046.528. ISSN   0036-8075. PMID   13056598.
  24. ↑ Wolman, Yecheskel; Haverland, William J.; Miller, Stanley L. (1972). "Nonprotein Amino Acids from Spark Discharges and Their Comparison with the Murchison Meteorite Amino Acids". Proceedings of the National Academy of Sciences. 69 (4): 809–811. Bibcode:1972PNAS...69..809W. doi: 10.1073/pnas.69.4.809 . ISSN   0027-8424. PMC   426569 . PMID   16591973.
  25. ↑ Cronin, John R.; Pizzarello, Sandra (1997-02-14). "Enantiomeric Excesses in Meteoritic Amino Acids". Science. 275 (5302): 951–955. Bibcode:1997Sci...275..951C. doi:10.1126/science.275.5302.951. ISSN   0036-8075. PMID   9020072. S2CID   10979716.
  26. ↑ Elsila, Jamie E.; Callahan, Michael P.; Glavin, Daniel P.; Dworkin, Jason P.; Brückner, Hans (2011). "Distribution and Stable Isotopic Composition of Amino Acids from Fungal Peptaibiotics: Assessing the Potential for Meteoritic Contamination". Astrobiology. 11 (2): 123–133. Bibcode:2011AsBio..11..123E. doi:10.1089/ast.2010.0505. ISSN   1531-1074. PMID   21417942.
  27. ↑ Glavin, Daniel P.; Callahan, Michael P.; Dworkin, Jason P.; Elsila, Jamie E. (2010). "The effects of parent body processes on amino acids in carbonaceous chondrites: Amino acids in carbonaceous chondrites". Meteoritics & Planetary Science. 45 (12): 1948–1972. doi:10.1111/j.1945-5100.2010.01132.x. hdl: 2060/20100032396 . S2CID   62883414.
  28. ↑ Glavin, Daniel P.; Elsila, Jamie E.; McLain, Hannah L.; Aponte, José C.; Parker, Eric T.; Dworkin, Jason P.; Hill, Dolores H.; Connolly, Harold C.; Lauretta, Dante S. (2021). "Extraterrestrial amino acids and L-enantiomeric excesses in the CM 2 carbonaceous chondrites Aguas Zarcas and Murchison". Meteoritics & Planetary Science. 56 (1): 148–173. Bibcode:2021M&PS...56..148G. doi:10.1111/maps.13451. hdl: 10150/638053 . ISSN   1086-9379. S2CID   212671033.
  29. 1 2 Glavin, Daniel P.; Elsila, Jamie E.; Burton, Aaron S.; Callahan, Michael P.; Dworkin, Jason P.; Hilts, Robert W.; Herd, Christopher D. K. (2012). "Unusual nonterrestrial l-proteinogenic amino acid excesses in the Tagish Lake meteorite: l-amino acid excesses in the Tagish Lake meteorite". Meteoritics & Planetary Science. 47 (8): 1347–1364. doi:10.1111/j.1945-5100.2012.01400.x. S2CID   52227545.
  30. 1 2 Glavin, Daniel P.; Burton, Aaron S.; Elsila, Jamie E.; Aponte, José C.; Dworkin, Jason P. (2020-06-10). "The Search for Chiral Asymmetry as a Potential Biosignature in our Solar System". Chemical Reviews. 120 (11): 4660–4689. doi: 10.1021/acs.chemrev.9b00474 . ISSN   0009-2665. PMID   31743015. S2CID   208185504.
  31. ↑ Garcia, Adrien D.; Meinert, Cornelia; Sugahara, Haruna; Jones, Nykola C.; Hoffmann, Søren V.; Meierhenrich, Uwe J. (2019-03-16). "The Astrophysical Formation of Asymmetric Molecules and the Emergence of a Chiral Bias". Life. 9 (1): 29. Bibcode:2019Life....9...29G. doi: 10.3390/life9010029 . ISSN   2075-1729. PMC   6463258 . PMID   30884807.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.