kosmos: CI chondrite

Evidence: 43 • authority: 88

Extraterrestrial amino acids in Orgueil and Ivuna: Tracing the parent body of CI type carbonaceous chondrites. Amino acid analyses using HPLC of pristine interior pieces of the CI carbonaceous chondrites Orgueil and Ivuna have found that β-alanine, glycine, and γ-amino- n -butyric acid (ABA) are the most abundant amino acids in these two meteorites, with concentrations ranging from ≈600 to 2,000 parts per billion (ppb). Other α-amino acids such as alanine, α-ABA, α-aminoisobutyric acid (AIB), and isovaline are present only in trace amounts (<200 ppb). Carbon isotopic measurements of β-alanine and glycine and the presence of racemic (D/L ≈ 1) alanine and β-ABA in Orgueil suggest that these a…

Evidence: 36 • authority: 92

Iron isotope evidence for very rapid accretion and differentiation of the proto-Earth.. Nucleosynthetic isotope variability among solar system objects provides insights into the accretion history of terrestrial planets. We report on the nucleosynthetic Fe isotope composition (μ 54 Fe) of various meteorites and show that the only material matching the terrestrial composition is CI (Ivuna-type) carbonaceous chondrites, which represent the bulk solar system composition. All other meteorites, including carbonaceous, ordinary, and enstatite chondrites, record excesses in μ 54 Fe. This observation is inconsistent with protracted growth of Earth by stochastic collisional accretion, which predicts…

Evidence: 100 • authority: 72

CI chondrites, also called C1 chondrites or Ivuna-type carbonaceous chondrites, are a group of rare carbonaceous chondrites, a type of stony meteorite. They are named after the Ivuna meteorite, the type specimen. They represent the most chemically primitive meteorites known, with elemental compositions closely matching the Sun. These rare carbonaceous chondrites are defined by their lack of visible chondrules due to extensive aqueous alteration. Despite this alteration, they preserved the solar system's original elemental composition, making them the standard reference material for cosmic abundances in planetary science. The Orgueil, Alais, Ivuna, Tonk, and Revelstoke meteorites, along with…

Evidence: 52 • authority: 88

Spectral Effects of Heating C3.00-Ungrouped Chwichiya 002 and Other Type 3 Carbonaceous Chondrites Under Vacuum. Three petrological type-3 carbonaceous chondrites; C3.00-ungrouped Chwichiya 002, CV3ox NWA 14743, and CK3 NWA 15337 were heated under vacuum up to 700℃. Additionally, carbonaceous chondrite matrix constituents: saponite and serpentine were also heated under the same conditions up to 900℃. Bi-directional reflectance spectroscopy data were collected under vacuum. The spectra show variability in their albedo as temperature increases. Measurements were made using a Bruker 80v FTIR spectrometer, at a resolution of 4 cm-1, relative to Spectralon and InfraGold in the VISNIR and IR, res…

Evidence: 52 • authority: 72

A meteorite is a rock that originated in outer space and has fallen to the surface of a planet or moon. When the original object enters the atmosphere, various factors such as friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate energy. It then becomes a meteor and forms a fireball, also known as a shooting star; astronomers call the brightest examples "bolides". Once it settles on the larger body's surface, the meteor becomes a meteorite. Meteorites vary greatly in size. For geologists, a bolide is a meteorite large enough to create an impact crater. Meteorites that are recovered after being observed as they transit the atmosphere and imp…

Evidence: 43 • authority: 72

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 (2.2 tons) were recovered. The availability of large quantities of samples of the scientifically important carbonaceous 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. Carbonaceous…

Evidence: 42 • authority: 72

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.

Evidence: 36 • authority: 92

Advances in Cosmochemistry Enabled by Antarctic Meteorites.. At present, meteorites collected in Antarctica dominate the total number of the world's known meteorites. We focus here on the scientific advances in cosmochemistry and planetary science that have been enabled by access to, and investigations of, these Antarctic meteorites. A meteorite recovered during one of the earliest field seasons of systematic searches, Elephant Moraine (EET) A79001, was identified as having originated on Mars based on the composition of gases released from shock melt pockets in this rock. Subsequently, the first lunar meteorite, Allan Hills (ALH) 81005, was also recovered from the Antarctic. Since then, man…

Evidence: 34 • authority: 72

162173 Ryugu (provisional designation 1999 JU3) is a near-Earth object and also a potentially hazardous asteroid of the Apollo group. It measures approximately 900 metres (3,000 ft) in diameter and is a dark object of the rare spectral type Cb, with qualities of both a C-type asteroid and a B-type asteroid. In June 2018, the Japanese spacecraft Hayabusa2 arrived at the asteroid. After making measurements and taking samples, Hayabusa2 left Ryugu for Earth in November 2019 and returned the sample capsule to Earth on 5 December 2020. The samples showed the presence of organic compounds, such as uracil (one of the four components in RNA) and vitamin B3.

Evidence: 34 • authority: 92

Ryugu and Bennu preserve primordial isotopic heterogeneity absent from the meteorite record.. Ivuna-type (CI) carbonaceous chondrites are commonly used as proxies for the composition of the planet-forming disk because their chemical abundances resemble those of the solar photosphere. However, their isotopic uniformity may reflect pervasive alteration and isotopic averaging rather than preservation of the earliest Solar System reservoirs. Here we show that samples returned from the asteroids Ryugu and Bennu preserve isotopic heterogeneity in major planet-building elements, including magnesium, silicon, and iron, that is absent from CI chondrites and unresolved in other meteorites. These sign…

Evidence: 34 • authority: 92

The Ni isotopic composition of Ryugu reveals a common accretion region for carbonaceous chondrites.. The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grain…

Evidence: 34 • authority: 72

A chondrite (, CON-drite) 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%. Their study provides important clues for understanding the origin and age of the Solar System, the synthesis of organic compounds, and the origin of life and the presence…