Results 151 to 160 of about 123,357 (335)

Space weathering of asteroids [PDF]

open access: yesarXiv, 2012
Analysis of laboratory experiments simulating space weathering optical effects on atmosphereless planetary bodies reveals that the time needed to alter the spectrum of an ordinary chondrite meteorite to resemble the overall spectral shape and slope of an S-type asteroid is about ~ 0.1 Myr.
arxiv  

Selective sampling of asteroids, the Moon, and Mars: Factors affecting the numerical abundances of members of meteorite groups

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Meteorite collection inventories show that many related meteorite groups have very different numerical abundances (e.g., lunar versus Martian meteorites; Eagle Station pallasites versus main‐group pallasites; eucrites versus diogenites; ungrouped Antarctic irons versus ungrouped non‐Antarctic irons; carbonaceous chondrite‐related (CC) iron ...
Alan E. Rubin
wiley   +1 more source

Identifying LL Chondrite Near-Earth Asteroids Using LL Chondrite Reflectance Spectra

open access: yesThe Astrophysical Journal Letters
Most near-Earth objects are thought to originate from the collisional fragments of the main asteroid belt. One question that remains to be resolved is the proportion of near-Earth objects sampling the core area material of the parent body to the outer ...
Pengyue Wang   +3 more
doaj   +1 more source

OBSERVATION OF ASTEROID OCCULTATIONS WITH HELP OF THE METHOD OF TEMPORAL UNSQUEEZING CCD-IMAGES IN 2006

open access: yesOdessa Astronomical Publications, 2017
Description of the method of temporal unsqueezing CCD-images is presented for observations of asteroids occultations. The method was applied for observations of 9 asteroid occultations with telescope AZT - 8 (D = 0.7m, F = 2.8m) and CCD ST - 8MXE in ...
F. I. Kravtsov, I. V. Lukyanyk
doaj   +1 more source

Global Asteroid Risk Analysis [PDF]

open access: yesarXiv, 2014
Potentially impacting asteroids were analysed for their impact risk on the Earth. To this end, the Asteroid Risk Mitigation Optimization and Research (ARMOR) tool is currently being developed. The tool's modules are described and their validation is documented.
arxiv  

Experimental simulations of space weathering on pentlandite

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Pentlandite (Fe, Ni)9S8 is an important accessory mineral on asteroidal surfaces. It has been identified in returned regolith samples from asteroids Itokawa, Ryugu, and Bennu. Currently, systematic studies to understand the response of this mineral phase under space weathering conditions are lacking.
L. C. Chaves   +8 more
wiley   +1 more source

Unusual Space Weathering on a CE-5 Metal Grain Indicates Deceptive Surface Signatures of M-type Asteroids

open access: yesThe Astrophysical Journal Letters
M-type asteroids are historically thought to be exposed metallic cores of differentiated planets with a composition dominated by pure iron and nickel. However, recent spectral and radar observations reveal an insufficient number of M-type asteroids in ...
Tian Zhang   +7 more
doaj   +1 more source

Low‐temperature dissociation of zircon in highly alkaline conditions: A cautionary note for studies on natural glasses of debated origin

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract Dissociated zircon is largely used as a robust indicator of glasses generated by impact cratering and airbursts. The reaction of zircon dissociation, i.e. ‘ZrSiO4 → ZrO2 + SiO2’, requires high temperatures (>1670°C) only reached by extreme geological processes. Using high‐temperature experiments, this study shows that zircon can dissociate and
A. Musolino   +8 more
wiley   +1 more source

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