Results 51 to 60 of about 5,498 (201)

Оптимальное управление движением космического аппарата в поле притяжения астероида Эрос 433

open access: yesВестник Самарского университета: Аэрокосмическая техника, технологии и машиностроение, 2019
Рассматривается алгоритм оптимизации управляемого движения космического аппарата с двигателями малой тяги в поле притяжения астероида Эрос 433. Гравитационное поле астероида имеет сложную конфигурацию.
А. Ю. Шорников
doaj   +1 more source

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis   +5 more
wiley   +1 more source

AGONISM IN ASTEROIDS

open access: yesThe Biological Bulletin, 1975
1. Intraspecific agonistic behavior, called bouts, which involves ray interactions between individual sea stars, is reported in species from all three living orders of asteroids and described for Patiria miniata and Pycnopodia helianthoides. This behavior indicates a certain sensitivity to conspecific contact on the aboral surface, in which each ...
openaire   +3 more sources

Noble gases and nitrogen in material from asteroid Bennu

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty   +7 more
wiley   +1 more source

Static recrystallization of shocked calcite in Ries impact breccias

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Calcite is prone to chemical and microstructural modifications, especially after having been strained at high stresses and strain rates, as during hypervelocity impact events. These modifications include precipitation from pore fluid as well as replacement of strained volumes by recrystallization. In calcite aggregates of a metagranite breccia
Claudia A. Trepmann   +8 more
wiley   +1 more source

Holocene impact craters on Earth

open access: yesMiscellanea Geographica: Regional Studies on Development, 2023
Impact craters are formed by collisions of cosmic bodies moving with hypervelocity. The formation of these features is not restricted to the distant geological past; new structures are constantly being created and at least 13 confirmed impact craters and
Losiak Anna
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

Thermal histories of El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155): Implications for the diversity of IAB‐ungrouped iron meteorites and their parent bodies

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract This study provides the first petrographic, crystallographic, and chemical comparison between El Médano 300 (EM 300) and Northwest Africa 8155 (NWA 8155), two particular IAB‐ungrouped iron meteorites. Both contain exceptionally large graphite nodules and “flowers”, providing unique insights into carbon behavior in metallic melts and cooling ...
L. Perez   +8 more
wiley   +1 more source

Simulation of the Dual-Frequency Radar Image of Asteroid 2016 HO3 and Implication for Tianwen-2 Mission

open access: yesIEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
In China's Tianwen-2 mission, a dual-frequency radar will be carried out to detect the asteroid 2016 HO3. The dual-frequency radar can acquire the information of the asteroid's surface and internal structure. There are few studies about the
Niutao Liu, Ya-Qiu Jin, Feng Xu
doaj   +1 more source

Visible, near‐, and thermal infrared spectra of asteroid Bennu samples: Relationship to and implications for remote sensing of carbonaceous asteroids

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Remote spectroscopy is used to characterize the mineralogy and infer the history of planetary bodies. Carbonaceous asteroids, such as B‐type (101955) Bennu, represent the earliest stages of planet formation. B types have a blue (negative) spectral slope and comprise <5% of asteroids.
V. E. Hamilton   +32 more
wiley   +1 more source

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