Podrobnosti záznamu

Název
    Density, porosity, mineralogy, and internal structure of cosmic dust and alteration of its properties during high-velocity atmospheric entry
Autor
    Badjukov, D. D.
    Böhmová, Vlasta
    Čuda, J.
    Gattacceca, J.
    Hutzler, A.
    Kallonen, A.
    Kohout, Tomáš
    Rochette, P.
    Skála, Roman
    Suuronen, J.-P.
Jazyk
    anglicky
Typ dokumentu
    článek v odborném periodiku
Zdrojový dokument - seriál
    Meteoritics & Planetary Science
Svazek/č.
    Roč. 49, č. 7
Strany
    s. 1157-1170
Rok
    2014
Poznámky
    Projekt: LH12079, GA MŠk3cav_un_auth*0281796
    Rozsah: 14 s. : P
Předmětová kategorie
    density
    meteoroid
    micrometeorite
    porosity
    tomography
Klíčové slovo
    Alteration
    Atmospheric
    Cosmic
    Density
    During
    Dust
    Entry
    High-velocity
    Internal
    Mineralogy
    Porosity
    Properties
    Structure
Abstrakt (anglicky)
   X-ray microtomography (XMT), X-ray diffraction (XRD), and magnetic hysteresis measurements were used to determine micrometeorite internal structure, mineralogy, crystallography, and physical properties at μm resolution. The study samples include unmelted, partially melted (scoriaceous), and completely melted (cosmic spherules) micrometeorites. This variety not only allows comparison of the mineralogy and porosity of these three micrometeorite types but also reveals changes in meteoroid properties during atmospheric entry at various velocities. At low entry velocities, meteoroids do not melt and their physical properties do not change. The porosity of unmelted micrometeorites varies considerably (0-12%) with one friable example having porosity around 50%. At higher velocities, the range of meteoroid porosity narrows, but average porosity increases (to 16-27%) due to volatile evaporation and partial melting (scoriaceous phase).
   Metal distribution seems to be mostly unaffected at this stage. At even higher entry velocities, complete melting follows the scoriaceous phase. Complete melting is accompanied by metal oxidation and redistribution, loss of porosity (1 ? 1%), and narrowing of the bulk (3.2 ? 0.5 g cm-3) and grain (3.3 ? 0.5 g cm-3) density range. Melted cosmic spherules with a barred olivine structure show an oriented crystallographic structure, whereas other subtypes do not.
Přispěvatel
    AV ČR Brno, Geologický ústav
Kód přispěvatele
    AV ČR, GLÚ
Zdrojový formát
    U
Datum importu
    23. 10. 2014