Title :

Fine-grained material encased in microtracks of Stardust samples

Author(s) :

Leroux, Hugues [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Jacob, Damien [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]

Journal title :

Meteoritics and Planetary Science

Volume number :

48

Pages :

1607-1617

Publication date :

2013

HAL domain(s) :

Planète et Univers [physics]/Astrophysique [astro-ph]
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Physique [physics]/Astrophysique [astro-ph]
Planète et Univers [physics]/Sciences de la Terre
Chimie/Matériaux
Physique [physics]/Physique [physics]/Géophysique [physics.geo-ph]

English abstract : [en]

Dust from comet 81P/Wild 2 was captured at high speed in silica aerogel collectors during the Stardust mission. Studies of deceleration tracks in aerogel showed that a number of cometary particles were poorly cohesive and ...
Show more >Dust from comet 81P/Wild 2 was captured at high speed in silica aerogel collectors during the Stardust mission. Studies of deceleration tracks in aerogel showed that a number of cometary particles were poorly cohesive and fragmented during impact. Fragments are now scattered along the walls of impact cavities. Here, we report a transmission electron microscope study of a piece of aerogel extracted from the wall of track 10. We focused on micron‐sized secondary tracks along which fragments of a fine‐grained material are disseminated. Two populations of fragments were identified. The first is made of polycrystalline silicate assemblages (olivine, pyroxene, and spinel) that appear to be chemically related to each other. The second corresponds to silica‐rich glassy clumps characteristic of a mixture of melted cometary material and aerogel. A significant number of fragments have been found with a composition close to chondritic CI for the major elements Fe‐Mg‐S at a submicron scale. These fragments have thus never been chemically differentiated by high‐temperature processes prior to the accretion on the comet, in contrast to terminal particles, which are dominated by larger, denser, and frequently monomineralic components.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
ENSCL
CNRS
INRA

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Matériaux Terrestres et Planétaires

Submission date :

2019-06-03T08:52:37Z
2021-02-11T09:52:45Z