Results 41 to 50 of about 1,457 (188)

Model Calculations for Cosmogenic Nuclides in Meteorites and the Lunar Surface. 1. Long‐lived Radionuclides

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Production rates for the cosmogenic radionuclides 10Be, 14C, 26Al, 36Cl, 41Ca, 53Mn, and 60Fe in a large variety of meteorites, that is, ordinary chondrites (H, L, LL), carbonaceous chondrites, HED meteorites, ureilites, Martian meteorites, and iron meteorites and in the uppermost ~2 m of the lunar surface are modeled.
Ingo Leya
wiley   +1 more source

Meteorites and the RNA World: Synthesis of Nucleobases in Carbonaceous Planetesimals and the Role of Initial Volatile Content

open access: yesThe Astrophysical Journal, 2023
Prebiotic molecules, fundamental building blocks for the origin of life, have been found in carbonaceous chondrites. The exogenous delivery of these organic molecules onto the Hadean Earth could have sparked the polymerization of the first RNA molecules ...
Klaus Paschek   +5 more
doaj   +1 more source

Microspherules Formed by Lightning Strikes

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Natural microspherules are formed by high‐temperature processes and are present throughout the geologic record to the present day. We report the discovery of large numbers of microspherules recovered from a rock pavement in the Pilbara region, Western Australia.
M. R. Boyd, M. J. Genge, A. G. Tomkins
wiley   +1 more source

Terrestrial ages of meteorites from the Atacama Desert (Chile) and insights into the past meteorite flux to Earth

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The Atacama Desert in Chile is characterized by its high meteorite density and old meteorite terrestrial ages. In this work, we present new terrestrial ages derived from measurements of the concentration of cosmogenic 36Cl in the metal fraction of 51 ordinary chondrites collected over a 6.8 km2 area located in the Catalina Dense Collection ...
Carine Sadaka   +13 more
wiley   +1 more source

TAXONOMIC REVIEW OF CHONDRITES AFFINIS (STERNBERG, 1833) FROM CRETACEOUS-NEOGENE OFFSHORE-DEEP-SEA TETHYAN SEDIMENTS AND RECOMMENDATION FOR ITS FURTHER USE

open access: yesRivista Italiana di Paleontologia e Stratigrafia, 2012
The branched trace fossil Chondrites affinis (Sternberg, 1833), synonymised so far with C. targionii (Brongniart, 1828), has been analyzed in an exceptionally well preserved specimen from the Saraceno Formation (?Upper Cretaceous; ?Eocene-Miocene) in the
ALFRED UCHMAN   +2 more
doaj   +1 more source

The Magnesium Isotope Composition of Samples Returned from Asteroid Ryugu

open access: yesThe Astrophysical Journal Letters, 2023
The nucleosynthetic isotope composition of planetary materials provides a record of the heterogeneous distribution of stardust within the early solar system.
Martin Bizzarro   +89 more
doaj   +1 more source

Non‐innocent solvents in meteorite extractions: Evidence for artifact formation

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Solvent extraction is a cornerstone of meteoritic organic and inorganic chemistry, yet the assumption that common solvents act as chemically inert media is becoming increasingly untenable. This study reports that low‐molecular‐weight alcohols, particularly methanol and ethanol, are “non‐innocent” solvents when used to extract soluble sulfur ...
N. Randazzo   +6 more
wiley   +1 more source

Two faces of L-type asteroids

open access: yesAstronomy & Astrophysics
Context. L-types are a rare class of asteroids whose spectra indicate similarities with CO and CV chondrites, suggesting high abundances of refractory inclusions, particularly with respect to the calcium-aluminium-rich inclusion.
Mahlke M.   +8 more
doaj   +1 more source

Confirmation of the impact origin of the Late Ordovician Tvären impact structure (southeast Sweden) and emplacement of impactites in a marine setting

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The Tvären structure in southeastern Sweden has been listed as a confirmed marine‐target impact structure for decades. However, to date, no measurements and/or indexed data of planar deformation features in quartz grains from the structure have been published or any other unequivocal evidence of impact.
Katarzyna J. Gajewska   +6 more
wiley   +1 more source

The effect of terrestrial weathering on the magnetic properties of meteorites from the Atacama Desert

open access: yesУчёные записки Казанского университета: Серия Естественные науки
Once ordinary chondrites fall on Earth, Fe–Ni minerals and troilite they contain oxidize and transform into iron oxyhydroxides and/or iron oxides, which is expected to modify their magnetic properties.
D. Kuzina   +6 more
doaj   +1 more source

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