Trace amounts of glycine, serine, and alanine were detected in the carbonate component of the martian meteorite ALH84001 by high-performance liquid chromatography. The detected amino acids were not uniformly distributed in the carbonate component and ranged in concentration from 0.1 to 7 parts per million. Although the detected alanine consists primarily of the L enantiomer, low concentrations (|0.1 parts per million) of endogenous D-alanine may be present in the ALH84001 carbonates. The amino acids present in this sample of ALH84001 appear to be terrestrial in origin and similar to those in Allan Hills ice, although the possibility cannot be ruled out that minute amounts of some amino acids such as D-alanine are preserved in the meteorite.
Isotopic Evidence for Extraterrestrial Non-Racemic Amino Acids in the Murchison MeteoriteJournal article By: Michael H. Engel and Stephen A. MackoDate: September 18, 1997Source: Engel, Michael H. and Stephen A. Macko. Isotopic Evidence for Extraterrestrial Non-Racemic Amino Acids in the Murchison Meteorite. Nature 389 (September 18, 1997): 265. Source for information on Isotopic Evidence for Extraterrestrial Non-Racemic Amino Acids in the Murchison Meteorite: Environmental Issues: Essential Primary Sources dictionary.
The whole question of the biochemistry is: were the organic compounds definitely in the meteorite before it landed? Also, how many different kinds of compounds were there? The details below answer these questions as: Q1 yes; Q2 very many.. This type of meteorite is rich in carbon and among the most chemically primitive meteorites.[2] Murchison contains over 15 amino acids.[3] All the amino acids found in the Murchison meteorite have been synthesised in laboratory experiments by the action of electric discharge on a mixture of methane, nitrogen, and water with traces of ammonia.[3]. The amino acids were mostly racemic. This means the chirality of their enantiomers are almost equally left- and right-handed, which suggests they are not caused by terrestrial contamination. A complex mixture of alkanes was isolated as well, similar to that found in the Miller-Urey experiment. Serine and threonine, often earthly contaminants, were absent from the samples.. In 1997 research showed that individual ...
This bachelor thesis consists of two parts. The first part consists of a review of the theoretical background. It starts off with a shorter review on theories of the history of the early Solar System, from protostellar evolution to grain agglomeration. This is then followed by a brief summary of different kinds of meteorites, what their origins might be and the radiometric dating techniques used to determine their ages.. The second part of the thesis consists of an investigation of the possible forming times of the early planetesimals by computer simulation. These planetesimals can later become the parent bodies for iron-rich meteorites. Factors studied are ambient temperature and the abundance of the short-lived radioactive isotope 26Al in the forming nebula.. The study found that the parent bodies of iron meteorites had to accrete within the first few million years after the earliest solids in the Solar System, the CAI. It also found that changes in the studied boundary conditions did extend ...
Based on mineralogical and chemical evidence, including the high deuterium/hydrogen ratio of CI meteorites, it has been suggested recently that CI meteorites could be fragments of comets or extinct cometary nuclei (26, 27). Powdered samples of the CM meteorite Murchison heated up to 900°C show strong similarities in their reflectance spectra to C- and G-type asteroids, which points to an asteroidal origin for this CM meteorite (28). However, the link between CI and CM chondrites and comets and asteroids is not drawn clearly. In addition, it is unclear whether some small solar system objects such as Chiron, Wilson-Harrington, and Elst-Pizarro are comets or asteroids (29).. Observations of the recent comets Hyakutake and Hale-Bopp over the entire electromagnetic spectrum have established an inventory of cometary volatiles, including ammonia, HCN, and formaldehyde (30). Cyanoacetylene, one of the potential precursors of β-alanine, has been detected also in the coma of comet Hale-Bopp, in which ...
According to one version of the panspermia theory, life on Earth could originally have arrived here by way of meteorites from Mars, where conditions early in the history of the solar system are thought to have been more favorable for the creation of life from nonliving ingredients. The only problem has been how a meteorite could get blasted off of Mars without frying any microbial life hitching a ride.. But new research on the celebrated Martian meteorite ALH84001 shows that the rock never got hotter than 105 degrees Fahrenheit during its journey from the Red Planet to Earth, even during the impact that ejected it from Mars, or while plunging through Earths atmosphere before landing on Antarctic ice thousands of years ago.. In the October 27 issue of the journal Science, Caltech graduate student Benjamin Weiss, undergraduate student Francis Macdonald, geobiology professor Joseph Kirschvink, and their collaborators at Vanderbilt and McGill universities explain results they obtained when ...
The possible meteorite parent body origin of Earths pregenetic nucleobases is substantiated by the guanine (G), adenine (A) and uracil (U) measured in various meteorites.. Cytosine (C) and thymine (T) however are absent in meteorites, making the emergence of a RNA and later RNA/DNA/protein world problematic. We investigate the meteorite parent body (planetesimal) origin of all nucleobases by computationally modeling 18 reactions that potentially contribute to nucleobase formation in such environments. Out of this list, we identify the two most important reactions for each nucleobase and find that these involve small molecules such as HCN, CO, NH3, and water that ultimately arise from the protoplanetary disks in which planetesimals are built. The primary result of this study is that cytosine is unlikely to persist within meteorite parent bodies due to aqueous deamination. Thymine has a thermodynamically favourable reaction pathway from uracil, formaldehyde and formic acid, but likely did not ...
On the thermodynamics of meteorites and parent bodies II. : from chondrites through the primitive achondrite verities (stage A and stage B) to the basaltic achondrites. In: Acta mineralogica-petrographica, (40). pp. 175-198. (1999 ...
Planetary formation models show that terrestrial planets are formed by the accretion of tens of Moon- to Mars-sized planetary embryos through energetic giant impacts. However, relics of these large proto-planets are yet to be found. Ureilites are one of the main families of achondritic meteorites and their parent body is believed to have been catastrophically disrupted by an impact during the first 10 million years of the solar system. Here we studied a section of the Almahata Sitta ureilite using transmission electron microscopy, where large diamonds were formed at high pressure inside the parent body. We discovered chromite, phosphate, and (Fe,Ni)-sulfide inclusions embedded in diamond. The composition and morphology of the inclusions can only be explained if the formation pressure was higher than 20 GPa. Such pressures suggest that the ureilite parent body was a Mercury- to Mars-sized planetary embryo. Ureilites are a type of meteorite that are believed to be derived from a parent body that was
Article first published online: 8 SEP 2015. LINK. The CI1 Orgueil meteorite is a highly aqueously altered carbonaceous chondrite. It has been extensively studied, and despite its extensive degree of aqueous alteration and some documented instances of contamination, several indigenous organic compounds including amino acids, carboxylic acids, and nucleobases have been detected in its carbon-rich matrix. We recently developed a novel gas chromatographic method for the enantiomeric and compound-specific isotopic analyses of meteoritic aliphatic monoamines in extracts and have now applied this method to investigate the monoamine content in Orgueil. We detected 12 amines in Orgueil, with concentrations ranging from 1.1 to 332 nmol g−1 of meteorite and compared this amine content in Orgueil with that of the CM2 Murchison meteorite, which experienced less parent-body aqueous alteration. Methylamine is four times more abundant in Orgueil than in Murchison. As with other species, the amine content in ...
CI chondrites, sometimes C1 chondrites, are a group of rare stony meteorites belonging to the carbonaceous chondrites. Samples have been discovered in France, Canada, India, and Tanzania. Compared to all the meteorites found so far, their chemical composition most closely resembles the elemental distribution in the suns photosphere. The abbreviation CI is derived from the C for carbonaceous and from the I for Ivuna, the type locality in Tanzania. The 1 in C1 stands for the type 1 meteorites in the classification scheme of Van Schmus-Wood. Type 1 meteorites normally have no recognizable chondrules. There are very few finds of CI chondrites, six so far altogether. The oldest find dates back to the year 1806: two meteorites were seen near Alès (or Alais) in France. Consequently, two pieces weighing 6 kilograms were discovered at Saint-Étienne-de-lOlm and Castelnau-Valence, small villages S-E of Alès. In 1864 another fall happened in France at Orgueil near Montauban. The meteorite had ...
eabc3557, Published Online: 08 Oct 2020. LINK. The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 μm. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennus parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.. ...
Nakhla Meteorite Fragment, 1911. Thirty-four meteorites thought to have originated from Mars have been cataloged from around the world, including the Nakhla meteorite.. On June 28, 1911, the Nakhla meteorite fell to Earth at approximately 9 a.m. in the Nakhla region of Alexandria, Egypt. Many people witnessed its explosion in the upper atmosphere before the meteorite dropped in about 40 pieces totaling 22 pounds; the fragments were buried in the ground up to a meter deep.. In August 1911, the Smithsonian received two samples of Nakhla; in 1962, it received the 480-gram piece of the meteorite shown in this photograph. By the 1970s, the Smithsonian had acquired a total of 650 grams of Nakhlas fragments.. Nakhlites, Martian meteorites named for Nakhla, are igneous rocks that are rich in augite and were formed from basaltic magma about 1.3 billion years ago. Their crystallization ages, compared to a crater-count chronology of different regions on Mars, suggest the Nakhlites formed on the large ...
The variability of these constituents, not only from one chondrite to another but also within the same chondrite, is no trivial detail. An originating nebula of dust and gas would be expected to have been homogeneous over medium-scale distances. Assuming that the solar system came from such a nebula, one has to excuse the variability by supposing that, for example, the separate classes of chondrules were derived from separate regions and that mixing subsequent to chondrule formation was not thorough (Taylor 2001). That is, the chondrules accreted very quickly, before differences in their composition could be smoothed out.. CAIs and chondrules commonly include the decay products of several extinct, very short-lived radioactive elements such as iron-60 (written as 60Fe, a neutron-rich isotope of iron) and aluminium-26 (26Al), and it is these that enable a remarkably precise chronology for the early solar system to be determined. The very oldest constituents are the CAIs. Dating to 4,568 million ...
The irons display a range in values which is to too large to be the result of fractionation processes in the nebula. An explanation involving primordial heterogeneity is favoured, with the iron meteorite parent bodies having sampled at least four isotopically distinct nitrogen reservoirs. One of the factors controlling the variation may be an input of 1%-rich nitrogen, together with 26Al, from a nova event prior to solar nebula collapse. The behaviour of nitrogen during core formation processes is also considered and compared with the observed nitrogen variation in the non-magmatic group lAB. Other secondary processes affecting nitrogen in the iron meteorites are also identified. The isotopic composition of nitrogen has been used to identify genetic links between iron and stony meteorites, thereby enhancing the normal technique based on oxygen isotopic composition (prohibited by the rarity of oxygen bearing minerals ...
Jones R. H., Grossman J. N., and Rubin A. E. 2005. Chemical, mineralogical and isotopic properties of chondrules: Clues to their origin. In Chondrites and the protoplanetary disk, edited by Krot A. N., Scott E. R. D., and Reipurth B. ASP Conference Series Proceedings, vol. 341. San Francisco: Astronomical Society of the Pacific. pp. 251-281 ...
NWA 2737, a Martian meteorite from the Chassignite subclass, contains minute amounts (0.010 ± 0.005 vol%) of metal-saturated Fe-Ni sulfides. These latter bear evidence of the strong shock effects documented by abundant Fe nanoparticles and planar defects in Northwest Africa (NWA) 2737 olivine. A Ni-poor troilite (Fe/S = 1.0 ± 0.01), sometimes Cr-bearing (up to 1 wt%), coexists with micrometer-sized taenite/tetrataenite-type native Ni-Fe alloys (Ni/Fe = 1) and Fe-Os-Ir-(Ru) alloys a few hundreds of nanometers across. The troilite has exsolved flame-like pentlandite (Fe/Fe + Ni = 0.5-0.6). Chalcopyrite is almost lacking, and no pyrite has been found. As a hot desert find, NWA 2737 shows astonishingly fresh sulfides. The composition of troilite coexisting with Ni-Fe alloys is completely at odds with Chassigny and Nahkla sulfides (pyrite + metal-deficient monoclinic-type pyrrhotite). It indicates strongly reducing crystallization conditions (close to IW), several log units below the fO2 conditions ...
redOrbit Staff & Wire Reports - Your Universe Online. Scientists attempting to better understand the formation and the present-day layering of planet Earth have turned to ancient meteorites -- meteorites which they say could hold important clues to some of the Solar Systems earliest chemical processes.. Those meteorites are known as diogenites, and researchers from the Carnegie Institution, the Scripps Institution of Oceanography, and the University of Maryland studied nine samples (seven from Antarctica and two from the African desert).. Diogenites, they explained, may have come from the asteroid Vesta and are among the Solar Systems oldest remaining examples of heat-related chemical processing, Carnegie officials said in a recent statement.. Whats more, Vesta or their other parent bodies were large enough to have undergone a similar degree of differentiation to Earth, thus forming a kind of scale model of a terrestrial planet, they said. They were able to confirm that these samples came ...
Alice (3) alien gold (2) Geyser (1) Golden Age of Dinosaur Discovery (1) Death by GPS (1) Diggers episode (1) Elko Crater Field Nevada (1) Geology of Northern Arizona (1) Holocene crater (2) Magician of the Gods (1) Piltdown Fly (1) The Cloud - Great Ted Talk About Being A Scientist (1) Uranolithe fosslie Astronomie. vol. 7 p. 114 (1888) (1) War of the Worlds (1) Flood Debris (1) mega meteorite crater (1) Meteorite sickness (1) Sailing Stones (1) and Crater in the Gulf of Mexico (1) (Anomaly) Disputed (1) (Art) (1) (Online) (1) $2 million in gems (1) 000 (1) 000 Trained Geoscientists Predicted (1) 000 Year-old Giant Virus (1) 000-Year-Old (1) 1/5 (1) 10 Tons of Meteorites (1) 10/6 (1) 11500 BP (1) 12-year-old Boy (1) 124 miles in Diameter (1) 12th (1) 1490 Ching-yang (1) 14C (1) 14C Impacts (1) 177 Ounce (1) 1807 Meteorite Fall (1) 1908: The Tunguska Event (1) 1946) (1) 1954 Alabama Meteorite Strike (1) 1955 (1) 2 billion years (1) 2 million-year-old (1) 2.5 ...
Alice (3) alien gold (2) Geyser (1) Golden Age of Dinosaur Discovery (1) Death by GPS (1) Diggers episode (1) Elko Crater Field Nevada (1) Geology of Northern Arizona (1) Holocene crater (2) Magician of the Gods (1) Piltdown Fly (1) The Cloud - Great Ted Talk About Being A Scientist (1) Uranolithe fosslie Astronomie. vol. 7 p. 114 (1888) (1) War of the Worlds (1) Flood Debris (1) mega meteorite crater (1) Meteorite sickness (1) Sailing Stones (1) and Crater in the Gulf of Mexico (1) (Anomaly) Disputed (1) (Art) (1) (Online) (1) $2 million in gems (1) 000 (1) 000 Trained Geoscientists Predicted (1) 000 Year-old Giant Virus (1) 000-Year-Old (1) 1/5 (1) 10 Tons of Meteorites (1) 10/6 (1) 11500 BP (1) 12-year-old Boy (1) 124 miles in Diameter (1) 12th (1) 1490 Ching-yang (1) 14C (1) 14C Impacts (1) 177 Ounce (1) 1807 Meteorite Fall (1) 1908: The Tunguska Event (1) 1946) (1) 1954 Alabama Meteorite Strike (1) 1955 (1) 2 billion years (1) 2 million-year-old (1) 2.5 ...
The aqueously altered chondritic parent bodies were initially composed of icy dust containing silicates, and the ices mainly contained H2O, CO, and CO2 with some formaldehyde and ammonia (21). Decay of radioactive nuclides (most likely 26Al) and/or the occurrence of transient events, such as impact shocks (26), could have produced heat that melted the ices contained in the planetesimals to produce liquid water (27). The conditions of the aqueous alteration have been estimated to be 0° to 80°C (pH 6 to 12) for CM2 chondrites, 20° to 150°C (pH 7 to 10) for CI1 chondrites, ~120°C for CM1 chondrites, 50° to 150°C for CR chondrites, 0° to 340°C for CO and CV chondrites, and up to 260°C for ordinary chondrites (15), although these temperatures are rather uncertain. These warm and slightly alkaline conditions are preferable for the formose reaction to occur (28), and further condensation and carbonization produced complex macromolecular organic solids (5, 16). As shown in the present study, ...
Achondrite, any stony meteorite containing no chondrules (small, roughly spherical objects that formed in the solar nebula). The only exclusions are carbonaceous chondrites of the CI group, which, though they are clearly chondrites, are so heavily altered by water that any evidence for their having
Learn about meteorites, the difference between a meteor and a meteorite, and how to test a rock to see if its a meteorite using our meteorite identification guide.
Meteorites that fell from an asteroid impact that lit up the skies over California and Nevada in April are showing scientists just how complex an asteroid surface can be. A new study published in Science by an international team of researchers describes the speedy recovery of the meteorites and reports that this space rock is an unusual example from a rare group known as carbonaceous chondrites, which contain some of the oldest material in the solar system.
One of the main problems when generating hypotheses on the formation and evolution of objects in the Solar System is the lack of samples that can be analysed in the laboratory, where a large suite of tools are available and the full body of knowledge derived from terrestrial geology can be brought to bear. Direct samples from the Moon, asteroids and Mars are present on Earth, removed from their parent bodies and delivered as meteorites. Some of these have suffered contamination from the oxidising effect of Earths atmosphere and the infiltration of the biosphere, but those meteorites collected in the last few decades from Antarctica are almost entirely pristine. The different types of meteorites that originate from the asteroid belt cover almost all parts of the structure of differentiated bodies: meteorites even exist that come from the core-mantle boundary (pallasites). The combination of geochemistry and observational astronomy has also made it possible to trace the HED meteorites back to a ...
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Ramlat as Sahmah 510 (RaS 510) 20°32.763N, 55°30.106E. Al Wusta, Oman. Find: 2013 Feb 2. Classification: Ordinary chondrite (H3). History: Found by Edwin Gnos, Beda Hofmann, Urs Eggenberger, Thomas Burri and Pete Stephenson during a search for meteorites on February 2, 2013.. Physical characteristics: Single, dark brown individual.. Petrography: (B. Hofmann, NMBE and E. Gnos, MHNGE) Mean chondrule size 0.32±0.19 mm (n=67). Homogeneous glass present in some chondrules, more commonly in state of beginning crystallization.. Geochemistry: (N. Greber, Bern) Mineral compositions: olivines, Fa15.7±4.7 (Fa3.2-20.2, n=18). Pyroxene, Fs13.6±4.0Wo1.1±0.8 (Fs3.7-16.9Wo0.3-2.7, n=14).. Classification: Based on silicate compositions and mean chondrule size this is a H3 chondrite, shock grade S3, weathering W3.. Specimens: All at NMBE. ...
We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earths ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.. ...
A NASA team analyzing meteorite fragments that fell on a frozen lake in Canada says its actually caused by liquid water inside an asteroid, making the search for extraterrestrial life more tricky.. Our analysis of the amino acids in meteorite fragments from Tagish Lake gave us one possible explanation for why all known life uses only left-handed versions of amino acids to build proteins, says Dr Daniel Glavin of NASAs Goddard Space Flight Center.. Amino acid molecules come in two forms which are mirror images of each other. Life on Earth is based on so-called left-handed versions - but theres no reason why right-handed versions wouldnt work perfectly well.. All ordinary methods of synthetically creating amino acids result in equal mixtures of left- and right-handed amino acids. This leaves the question open as to how the left-handed versions came to predominate from what were presumably once equal quantities of left and right molecules.. In January, 2000, a large meteoroid exploded in the ...
Calama 080 22º27.941S, 68º38.858W. Antofagasta, Chile. Find: 2017 Oct 24. Classification: Ordinary chondrite (H4). History: Two fragments of meteorite (138.25 and 10.27 g) were found 24 October 2017 by the UrFU meteorite expedition-2017 in Chile (Pastukhovich A.Yu., Larionov M.Yu., Kruglikov N.A., Kolunin R.N.) near Chiu-Chiu.. Physical characteristics: Total mass is 148.52 g. The meteorite has roughly rounded shape. Exterior of the stone is desert polished. The surface and interior of the meteorite is light to dark-brown in color due to Fe-hydroxides. No fusion crust was observed.. Petrography: Classification (K. Dugushkina and S. Berzin, RAS-UB). The meteorite consists mostly of a fine-grained, inequigranula,r recrystallized matrix and chondrules (15%). Chondrite consists of olivine 60%, orthopyroxene 15%, clinopyroxene 7-10%, plagioclase 5-7%, chromite 1-2%, troilite 4-6%, Fe-Ni-metal 3-5%, with accessory apatite. Predominately porphyritic olivine (PO) and porphyritic olivine-pyroxene ...
Guy Consolmagno SJ (Vatican Observatory) and Daniel Britt (University of Tennessee) have made numerous measurements of the densities and porosities of meteorites. This requires measuring the total volume of a meteorite, then the total volume of grains in the meteorite. The difference between the two gives the volume of empty spaces.. Measuring the Total Volume and Density of a Meteorite. Long ago, the famous mathematician Archimedes (287-212 BC) determined how to measure the volume of an object. He showed that the volume of a rock, for example, could be measured easily by immersing it in water in a calibrated beaker. The level of the water will rise because the rock displaces a volume of water equal to the rocks volume. We have all noticed this when getting into a bathtub-the level of the water rises. If you measured the amount that the water level rose and then got out and weighed yourself, you could calculate your density. (This could be disturbing, however, because the lower your density the ...
This heavy 14k rose gold mans ring is inlaid with a raised piece of Gibeon meteorite. The meteorite has been etched with nitric acid to reveal the characteristic patterns, or Widmanstatten figures, of iron meteorites. This creates a stunning contrast to the rich color of the rose gold. Additionally, the Meteorite is cut to project above the top of the ring, giving it an attractive three dimensional effect. The ring weighs 17 grams total, is 9mm wide at top of the band, tapering to 7mm at the bottom, and is a size 11.75. It cannot be sized, but can be custom made in any size.. ...
When you hear the term contagious disease, what tends to come to mind? Perhaps its images of red-faced, watery-eyed people coughing, sneezing and rasping around in a public space when they should be home, resting in bed. Or maybe its the unpleasant memories of a firsthand experience with a bout of whooping cough, chickenpox or streptococcal pharyngitis (better known as strep throat).. What you probably did not think of was cancer.. However, there are in fact three types of contagious cancers, spread by the transfer of living cancer cells between organisms, which are currently known to exist in nature. These cancers can be found in domestic dogs, soft-shell clams and Tasmanian devils-with additional unknown strains likely occurring in other species. And its become the mission of Watson School of Biological Science 07 alumna Dr. Elizabeth Murchison to uncover and understand both their molecular mechanisms and evolutionary histories.. My focus is to investigate how these cancers became ...
Significant abundances of trapped argon, krypton, and xenon have been measured in shock-altered phases of the achondritic meteorite Elephant Moraine 79001 from Antarctica. The relative elemental abundances, the high ratios of argon-40 to argon-36 (≥ 2000), and the high ratios of xenon-129 to xenon-132 (≥ 2.0) of the trapped gas more closely resemble Viking data for the martian atmosphere than data for noble gas components typically found in meteorites. These findings support earlier suggestions, made on the basis of geochemical evidence, that shergottites and related rare meteorites may have originated from the planet Mars. ...
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A new type of carbonaceous chondrite, the Tagish Lake meteorite, exhibits a reflectance spectrum similar to spectra observed from the D-type asteroids, which are relatively abundant in the outer solar system beyond the main asteroid belt and have been inferred to be more primitive than any known meteorite. Until the Tagish Lake fall, these asteroids had no analog in the meteorite collections. The Tagish Lake meteorite is a carbon-rich (4 to 5 weight %), aqueously altered carbonaceous chondrite and contains high concentrations of presolar grains and carbonate minerals, which is consistent with the expectation that the D-type asteroids were originally made of primitive materials and did not experience any extensive heating.
Large N-15 excesses have been measured in individual interplanetary dust particles (IDPs); TEM, in combination with spectroscopic measurements of the same IDPs, shows N concentrations within the carbonaceous material, and much of this is in organic form. The isotopic signature suggests that formation of this N-bearing carbonaceous material was in a cold, presolar molecular cloud, and it is surmised that the solid material grain embedded in the N-15-rich carbonaceous matter could be of presolar origin.
Seifertite is a dense orthorhombic polymorph of silica with the scrutinyite (α-PbO2) type structure that was found as lamellae occurring together with dense silica glass lamellae in composite silica grains in the heavily shocked Martian meteorite Shergotty. The mineral is also intergrown in some grains with minor stishovite and a new unnamed monoclinic dense silica polymorph with a ZrO2-type structure. Seifertite has also been found in the Martian shergottite Zagami and is a minor constituent in other Martian shergottites. Chemical analyses of seifertite in Shergotty indicate major SiO2 with minor concentrations of Al2O3 and Na2O. Selected-area electron diffraction (SAED) and X-ray diffraction can be interpreted in terms of an orthorhombic pattern from a scrutinyite (α-PbO2) structure. The cell parameters are a = 4.097(1) Å, b = 5.0462(9) Å, c = 4.4946(8) Å, V = 92.92 Å3, Z = 4, and the space group is Pbcn or Pb2n. Density is (calc.) = 4.294 g/cm3 (with pure SiO2), 4.309 g/cm3 (with ...
A recurrent interpretation of ancient climate based on the oxygen isotopic composition of marine carbonates and cherts suggests that Earths climate was substantially warmer in the distant past and remained so until as recently as 400 Myr ago. This interpretation is difficult to reconcile with the long-term glacial record, with evidence for modest weathering rates during most of Earths history, with biomarker and fossil evidence for eukaryotes and even vertebrates at times of anomalously low δ18O values, and with the predicted faintness of the young Sun. We argue here, following earlier suggestions, that the low δ18O values in ancient rocks are a consequence of the low δ18O of ancient seawater. A modest increase in ocean depth with time, together with progressive increases in pelagic sedimentation on midocean ridge flanks since about 550 Ma, could account for the variation in seawater isotopic composition. The required change in ocean depth, coupled with thinning of the oceanic crust, is a ...
Professor Munir Humayun of the National High Magnetic Field Laboratory and the geological sciences department at FSU and Alan Brandon of NASA discovered an isotopic anomaly in the rare element osmium in primitive meteorites. The anomalous osmium was derived from small stars with a higher neutron density than that which formed our solar system. The findings of the researchers, who also included colleagues from the University of Maryland and Bern University in Switzerland, were recently published in the journal Science.. Our new data enabled us to catch a glimpse of the different star types that contributed elements to the solar system, the parental stars of our chemical matter, Humayun said. It opens a treasure trove of prospects for exploring the formation of the elements.. For about 50 years, scientists have known that all the elements beyond iron in the periodic table were made in stars by up to three nuclear processes. Osmium is mainly formed by two of those processes, the so-called ...
This thesis deals with the analysis of presolar silicates and oxides by high resolution mass spectrometry and electron microscopy techniques. This stardust was identified by its extreme oxygen isotopic anomalies, which point to nucleosynthetic reactions in stellar interiors, in the carbonaceous chondrite Acfer 094. Isotopic, chemical and mineralogical studies on these stardust grains therefore allow the testing of astrophysical questions on Earth, which are otherwise only accessible by spectroscopy and theoretical models. The class of presolar silicates has been identified only six years ago in 2002, although it was known already from spectroscopic observations that silicates represent the most abundant type of dust in the galaxy. The development of the NanoSIMS was a crucial step in this respect, because this ion probe with its superior spatial resolution of only 50 nm allowed the detection of the typically 300 nm sized presolar silicates. A total of 142 presolar silicates and 20 presolar ...
Near Earth Objects (NEOs) are small solar system bodies whose orbits sometimes bring them close to the Earth, making them potential collision threats. NEOs also offer clues to the composition, dynamics and environmental conditions of the early solar system and its evolution, and because they are relatively close to the Earth they lend themselves to astronomical measurements. Most NEOs are discovered in optical searches, but one crucial NEO parameter, its size, usually cannot be determined from optical detections alone. This is because an NEOs optical light is reflected sunlight, and an object can be bright either because it is large or because it has a high reflectivity. A CfA team has been using the IRAC infrared camera on Spitzer to measure NEO infrared emission signals which provide an independent measure of its size.
A calcium-aluminium-rich inclusion or Ca-Al-rich inclusion (CAI) is a submillimeter- to centimeter-sized light-colored calcium- and aluminium-rich inclusion found in carbonaceous chondrite meteorites. They are probably the oldest substances in the Solar System. The oldest age was measured in an inclusion of the CV3 carbonaceous chondrite Northwest Africa (NWA) 2364 and was dated at 4568.22 ± 0.17 Mya. CAIs consist of minerals that are among the first solids condensed from the cooling protoplanetary disk. They are thought to have formed as fine-grained condensates from a high temperature (>1300 K) gas that existed in the protoplanetary disk at early stages of Solar System formations. Some of them were probably remelted later resulting in distinct coarser textures. The most common and characteristic minerals in CAIs include anorthite, melilite, perovskite, aluminous spinel, hibonite, calcic pyroxene, and forsterite-rich olivine. Using lead (Pb-Pb) isotopic dating of a CAI from NWA 2364, an age of ...
Ok. Lets get some terminology down first. If a body (like the Earth) is orbiting around the Sun, we say it is closest to the Sun at perihelion and farthest from the Sun at aphelion. If a body (like the Moon) is orbiting around the Earth, its closest point to the Earth is perigee and its farthest point from the Earth is apogee. In 2000, perihelion for the Earth was on January 3, 2000, and aphelion was on July 4, 2000. The Earth was 91,405,436 miles from Sun at perihelion and 94,511,989 miles from Sun at aphelion. For the year 2001, perihelion will occur on January 3, 2001 and aphelion will occur on July 4, 2001. The actual date for perihelion and aphelion will differ from year to year. But, you can see that the Earth is closest to the Sun in January and farthest from the Sun in July!. This may not seem right. I mean its winter in the northern hemisphere in January and yet we are closest to the Sun. But, our seasons are actually determined by the tilt of the Earth and not the Earths proximity ...
Ok. Lets get some terminology down first. If a body (like the Earth) is orbiting around the Sun, we say it is closest to the Sun at perihelion and farthest from the Sun at aphelion. If a body (like the Moon) is orbiting around the Earth, its closest point to the Earth is perigee and its farthest point from the Earth is apogee. In 2000, perihelion for the Earth was on January 3, 2000, and aphelion was on July 4, 2000. The Earth was 91,405,436 miles from Sun at perihelion and 94,511,989 miles from Sun at aphelion. For the year 2001, perihelion will occur on January 3, 2001 and aphelion will occur on July 4, 2001. The actual date for perihelion and aphelion will differ from year to year. But, you can see that the Earth is closest to the Sun in January and farthest from the Sun in July!. This may not seem right. I mean its winter in the northern hemisphere in January and yet we are closest to the Sun. But, our seasons are actually determined by the tilt of the Earth and not the Earths proximity ...
t is well established that earthquake faulting can create permeability along a fault zone in high competence rocks - by mismatch of the fault walls and by secondary fracture in a surrounding damage zone - and that this permeability is created repeatedly during successive earthquake cycles. Less well proven is that such permeability is transient, being episodically reduced by precipitation of cements in the fracture porosity. The textures of carbonate dilation breccias, formed at around 1.7 km depth on the Dent Fault zone (NW England), lend support to this economically important concept of transient fracture permeability. The key observation is that many breccias reflect only a single episode of brecciation and reseal. A generally applicable explanation of such single-phase breccias is that they were resealed in the interval between major earthquakes, that this reseal made the breccia stronger that the intact rock, and that subsequent brecciation in the same rock volume was inhibited. This ...
One result was breccia, a sedimentary rock composed of cemented rock fragments. The breccia at Blue Jay Barrens is primarily limestone with a cementing agent of sphalerite, an ore of zinc that is often mined when found in sufficient quantity. Poor land management in the early 1900s caused severe soil erosion to occur on large areas of Blue Jay Barrens. On the site pictured, the soil was completely lost and a large area of breccia was exposed. The sphalerite proved to be a poor cementing agent and breccia exposed to the elements quickly lost its cohesion and returned to its fragmented condition ...
Abstract : Amino acids are the essential molecular components of living organisms on Earth, but the proposed mechanisms for their spontaneous generation have been unable to account for their presence in Earths early history. The delivery of extraterrestrial organic compounds has been proposed as an alternative to generation on Earth, and some amino acids have been found in several meteorites. Here we report the detection of amino acids in the room-temperature residue of an interstellar ice analogue that was ultraviolet-irradiated in a high vacuum at 12 K. We identified 16 amino acids ; the chiral ones showed enantiomeric separation. Some of the identified amino acids are also found in meteorites. Our results demonstrate that the spontaneous generation of amino acids in the interstellar medium is possible, supporting the suggestion that prebiotic molecules could have been delivered to the early Earth by cometary dust, meteorites or interplanetary dust particles.. ...
TY - JOUR. T1 - The 3D morphology of the ejecta surrounding VY Canis Majoris. AU - Jones, Terry J. AU - Humphreys, Roberta M. AU - Helton, L. Andrew. N1 - Copyright: Copyright 2008 Elsevier B.V., All rights reserved.. PY - 2007/3. Y1 - 2007/3. N2 - We use second epoch images taken with WFPC2 on the HST and imaging polarimetry taken with the HST/ACS/HRC to explore the three dimensional structure of the circumstellar dust distribution around the red supergiant VY Canis Majoris. Transverse motions, combined with radial velocities, provide a picture of the kinematics of the ejecta, including the total space motions. The fractional polarization and photometric colors provide an independent method of locating the physical position of the dust along the line-of-sight. Most of the individual arc-like features and clumps seen in the intensity image are also features in the fractional polarization map, and must be distinct geometric objects. The location of these features in the ejecta of VY CMa using ...
Xenolith DU-1 contains heterogeneous domains of ilmenite-rich breccia surrounded by spinel harzburgite wall rock. The breccia domains also host resorbed Cr-diopside porphyroclasts and occasional Fe-Ni-Co sulphides segregations. Ilmenite occurs as large (up to 5 cm), chemically zoned lenses, associated with minor rutile. The ilmenite has Hf isotope values (initial εHf=2.1-3.0) in the range of South African Group I kimberlites and associated megacrysts. The ilmenite lenses host primary multiphase carbonate-rich, olivine-dominated, phlogopite-dominated and sulphide mineral inclusions. Carbonate-rich inclusions host abundant magnesite and dolomite, with subordinate kalsilite, phlogopite, alkali-carbonates, phosphates and chlorides. The occurrence of carbonate-rich inclusions suggests entrapment of a Ca-Mg-rich alkali-carbonate melt during ilmenite growth. However, geochemical modelling indicates that this melt was not parental to the ilmenite. Instead, it is suggested that the ilmenite (and other ...
The meteoroid grazed Earths atmosphere quite gently (in comparison to, for example, the 1972 Great Daylight Fireball above the United States and Canada). It became visible north of Uherský Brod, Czechoslovakia, at a height of 103.7 km, approaching the Earths surface to 98.67 km[note 2] northeast of Wrocław, Poland, and disappearing from sight at a height of 100.4 km north of Poznań, Poland. It would probably still have been visible until it reached a height of 110 km above the southern Baltic Sea.[1] The meteoroids absolute magnitude (the apparent magnitude it would have at an altitude of 100 km at the observers zenith) was approximately −6 and did not vary significantly during the few seconds of observation. It traveled a distance of 409 km in 9.8 seconds during the time it was observed. It moved at a speed of 41.74 km per second,[note 3] which did not change measurably during the flight.[4] Jiří Borovička and Zdeněk Ceplecha from the Ondřejov Observatory in Czechoslovakia ...
Lin, Y. T., El Goresy, A., Hu, S., Zhang, J. C., Gillet, P., Xu, Y. C., Hao, J. L., Miyahara, M., Ouyang, Z. Y., Ohtani, E., Xu, L., Yang, W., Feng, L., Zhao, X. C., Yang, J., Ozawa, S. (2014a). NanoSIMS analysis of organic carbon from the Tissint Martian meteorite: Evidence for the past existence of subsurface organic-bearing fluids on Mars. Meteoritics & Planetary Science 49, 2201-2218 ...
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To assess the environmental perturbation induced by the impact event that marks the Cretaceous-Tertiary (K-T) boundary, concentrations and isotopic compositions of bulk organic carbon were determined in sedimentary rocks that span the terrestrial K-T boundary at Dogie Creek, Montana, and Brownie Butte, Wyoming in the Western Interior of the United States. The boundary clays at both sites are not bounded by coals. Although coals consist mainly of organic matter derived from plant tissue, siliceous sedimentary rocks, such as shale and clay, may contain organic matter derived from microbiota as well as plants. Coals record ??13C values of plant-derived organic matter, reflecting the ??13C value of atmospheric CO2, whereas siliceous sedimentary rocks record the ??13C values of organic matter derived from plants and microbiota. The microbiota ??13C value reflects not only the ??13C value of atmospheric CO2, but also biological productivity. Therefore, the siliceous rocks from these sites yields information
The famous fragment of Mars, once proposed to hold signs of extraterrestrial life, is still pretty old. But the rock appears to have formed about 400 million years later than earlier analyses indicated.
In the second pathway, glycine is degraded in two steps. The first step is the reverse of glycine biosynthesis from serine with serine hydroxymethyl transferase. Serine is then converted to pyruvate by serine dehydratase.[26]. In the third pathway of its degradation, glycine is converted to glyoxylate by D-amino acid oxidase. Glyoxylate is then oxidized by hepatic lactate dehydrogenase to oxalate in an NAD+-dependent reaction.[26]. The half-life of glycine and its elimination from the body varies significantly based on dose.[27] In one study, the half-life varied between 0.5 and 4.0 hours.[27]. Glycine is extremely sensitive to antibiotics which target folate, and blood Glycine levels drop severely within a minute of antibiotic injections. Some antibiotics can deplete more than 90% of Glycine within a few minutes of being administered.[28]. ...
Abstract The paper presents the principle of a method to measure infiltration rates in sewer systems based on the use of oxygen isotopes and its application in Lyon (France). Investigations in the urban area of Lyon benefit from the isotopic differences between underground waters originating from the two rivers Rhône and Saône and from their associated alluvial aquifers. The oxygen isotopic composition of the Rhône water is roughly 3 ‰ lighter than that of the Saône river, due to the large differences in the mean altitude and topographic situation of their catchments. Large amounts of water are pumped from the Rhône aquifer for drinking water supply. As a consequence, this difference in the oxygen isotopic composition between wastewater and local groundwater can be used to evaluate infiltration in sewers in some parts of the city. The results obtained in a case study allow to evaluate the reliability and the uncertainties of this method. ...
Scientists have a few tantalizing clues about what kind of environment ancient Mars might have been. Little bits of the planet have been raining down on Earth for millions of years, originating from ancient Martian impacts. Most known Martian meteorites have been radiometrically aged to be between 0.5 million and 1.5 billion years old. This is the time they were dislodged from the planet and shot into space. The rock inside them, however, can be much older, on the scale of billions of years old. One meteorite in particular caused a big stir in the scientific community when it was discovered in 1985. It was found in Alan Hills in Antarctica and it is called ALH 84001. This meteorite appears to have been ejected from Mars about 16 million years ago and arrived on Earth 13,000 years ago. Cracks in it are filled with carbonate materials that imply the presence of liquid water. These minerals have been aged to between 4 and 3.6 billion years old. They also found evidence for polycyclic aromatic ...
Non-destructive analytical methods can be performed on meteorites, such as X-ray tomography and fluorescence, measurements of the density, volume, and magnetic susceptibility and gamma rays from radioactive decays. Because they are non-destructive such methods are nowadays often applied on precious extraterrestrial samples before anything destructive. However, many essential methods in meteoritics are destructive and require partial consumption of specimens. The cutting, grinding, and polishing of a specimen to prepare a polished section for classification, study of mineralogy, and surface analysis already consumes some material. To establish a chronology of the Solar System, dating of meteorites or their components by mass spectrometry is necessary. This requires dissolution chemistry, combustion, or melting. Thanks to improved instruments, analytical techniques, and protocols, detection sensitivities increase, and smaller samples can be used. Another notable example that requires destruction ...
A method of delivering a solar system and related services from a solar system vendor to a customer is provided. The method includes estimating the customers solar system requirements, delivering the estimated requirements to the customer, providing a sales lead that includes the estimated requirements to a contractor, the contractor contacting the customer to perform a sales close, ordering the solar system products from the solar system vendor, and issuing a payment for the products to the solar system vendor. The method of delivering solar services further includes supplying a first set of solar system components from the solar system vendor and a second set of solar system components from a third-party vendor, configuring all or a portion of the solar system components in accordance with the solar system requirements, shipping the solar system to the customers site, and installing the system on the customers site. The method for delivering solar services further includes financing the solar
Curtin University planetary scientists have shed some light on the bombardment history of our solar system by studying a unique volcanic meteorite recovered in Western Australia.
The abundance and isotopic composition of the noble gases were measured in three Spring-field specimens identified by the Denver Museum of Natural History with numbers 7029, 379.13 and 6040. The latter specimen contains more cosmogenic noble gas isotopes than the other two specimens and the abundance pattern of trapped noble gases in specimen 6040 is distinct from that in the other two specimens. Specimen 7029 contains about seven times as much radiogenic 40Ar and about four times as much radiogenic 129Xe as does specimen 379.13. These results indicate that the three specimens did not come from a single meteoroid. ...
The researchers found a hint of an excess of the chromium-54 isotope in their first session, but as luck would have it, they had to search 1,500 microscopic grains of the Orgueil and Murchison meteorites before finding just one with definitely high levels.. PhysOrg.com - latest science and technology news stories. ...
Meteorites are pieces of rock or metal that fall from space. The museum has a small, but representative, collection of meteorites, including several that fell in Northern Ireland. Among them is a 113kg iron meteorite, spectacular slices of stony iron pallasites, a small Lunar meteorite, and many small pieces from the great Russian meteorite fall of 2013. The largest meteorites can form huge craters and melt the target rocks. Examples of melted impactites are included in the museums displays and reference collection ...
Meteorites are pieces of rock or metal that fall from space. The museum has a small, but representative, collection of meteorites, including several that fell in Northern Ireland. Among them is a 113kg iron meteorite, spectacular slices of stony iron pallasites, a small Lunar meteorite, and many small pieces from the great Russian meteorite fall of 2013. The largest meteorites can form huge craters and melt the target rocks. Examples of melted impactites are included in the museums displays and reference collection ...
Artists conception of the Lucy and Psyche mission spacecraft (Left) An artists conception of the Lucy spacecraft flying by the Trojan Eurybates - one of...