نتایج جستجو برای: ordinary chondrite

تعداد نتایج: 50446  

2003
S. L. Andre T. J. McCoy J. E. McCamant M. S. Robinson

Introduction: Densities and porosities of meteorites provide information about the physical properties of their parent bodies (asteroids). Recent studies report the densities and porosities of ~40 ordinary chondrite (OC) meteorites [1,2]. In this study, we present 42 additional measurements of OC densities and porosities, and provide a rigorous analysis of the errors in the method. Additionally...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2012
Kathryn A Dyl Addi Bischoff Karen Ziegler Edward D Young Karl Wimmer Phil A Bland

Chondritic meteorites are considered the most primitive remnants of planetesimals from the early Solar System. As undifferentiated objects, they also display widespread evidence of water-rock interaction on the parent body. Understanding this history has implications for the formation of planetary bodies, the delivery of water to the inner Solar System, and the formation of prebiotic molecules....

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2012
Eizo Nakamura Akio Makishima Takuya Moriguti Katsura Kobayashi Ryoji Tanaka Tak Kunihiro Tatsuki Tsujimori Chie Sakaguchi Hiroshi Kitagawa Tsutomu Ota Yusuke Yachi Toru Yada Masanao Abe Akio Fujimura Munetaka Ueno Toshifumi Mukai Makoto Yoshikawa Jun'ichiro Kawaguchi

Records of micrometeorite collisions at down to submicron scales were discovered on dust grains recovered from near-Earth asteroid 25143 (Itokawa). Because the grains were sampled from very near the surface of the asteroid, by the Hayabusa spacecraft, their surfaces reflect the low-gravity space environment influencing the physical nature of the asteroid exterior. The space environment was exam...

2006
C. M. Pieters R. P. Binzel D. Bogard T. Hiroi H. Takeda

Although a direct link between the HED meteorites and the asteroid 4 Vesta is generally acknowledged, several issues continue to be actively examined that tie Vesta to early processes in the solar system. Vesta is no longer the only basaltic asteroid in the Main belt. In addition to the Vestoids of the Vesta family, the small asteroid Magnya is basaltic but appears to be unrelated to Vesta. Sim...

2013
J. Marvin Herndon

A new, indivisible planetary science paradigm, a wholly self-consistent vision of the nature of matter in the Solar System, and dynamics and energy sources of planets is presented here. Massivecore planets are formed by condensing and raining-out from within giant gaseous protoplanets at high pressures and high temperatures. Earth’s complete condensation included a ~300 Earth-mass gigantic gas/...

2003
S. J. Woodland M. Rehkämper D-C. Lee A. N. Halliday

Introduction: The now extinct radionuclide Pd decays to Ag with a half life of 6.5Myr. Highly volatile element depleted (i.e. high Pd/Ag) Group IVA iron meteorites show good correlations between excess Ag and Pd/Ag. This strongly indicates the presence of live Pd at the start of the solar system [1]. Pd is both more refractory and more siderophile than Ag. Hence condensation/evaporation process...

Journal: :Meteoritics & Planetary Science 2022

We report the results of petrological, geochemical, and geochronological investigations unusual K-rich L chondrite melt rock Northwest Africa 6486 (NWA 6486). The has slightly fractionated siderophile elements a mostly unfractionated pattern lithophile with exceptions enrichments in K Rb chondritic Sr abundance similar to inclusions found ordinary chondrites indicating fractionation alkaline th...

2003
V. P. Semenenko T. Stephan E. K. Jessberger

Introduction: In only two meteorites, Krymka and Supuhee, a very rare, fine-grained mysterious material has been discovered so far. Laul et al. [1] detected in these two ordinary chondrites an enrichment in Ag, Tl, and Bi. They concluded that this enrichment has its origin in a late condensate introduced during a brecciation event. Since a petrographic carrier of the volatiles could not be spec...

2010
V. A. Alexeev

Introduction: More than 80 L-chondritic fossil meteorites were found in Middle Ordovician limestone in the Thorsberg quarry at Kinnekulle in southern Sweden [1, 2]. All meteorite-bearing sediment beds at Thorsberg contain sediment-dispersed extraterrestrial chromite (SEC) grains of L chondrite composition [3]. Similar SEC grains were also found in several correlated sediment beds of other quarr...

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