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Journal articles
COMET 67P/CHURYUMOV-GERASIMENKO: CLOSE-UP ON DUST PARTICLE FRAGMENTS
Abstract : The COmetary Secondary Ion Mass Analyser instrument on board ESA's Rosetta mission has collected dust particles in the coma of comet 67P/Churyumov-Gerasimenko. During the early-orbit phase of the Rosetta mission, particles and particle agglomerates have been imaged and analyzed in the inner coma at distances between 100 km and 10 km off the cometary nucleus and at more than 3 AU from the Sun. We identified 585 particles of more than 14 μm in size. The particles are collected at low impact speeds and constitute a sample of the dust particles in the inner coma impacting and fragmenting on the targets. The sizes of the particles range from 14 μm up to sub-millimeter sizes and the differential dust flux size distribution is fitted with a power law exponent of -3.1. After impact, the larger particles tend to stick together, spread out or consist of single or a group of clumps, and the flocculent morphology of the fragmented particles is revealed. The elemental composition of the dust particles is heterogeneous and the particles could contain typical silicates like olivine and pyroxenes, as well as iron sulfides. The sodium to iron elemental ratio is enriched with regard to abundances in CI carbonaceous chondrites by a factor from ˜1.5 to ˜15. No clear evidence for organic matter has been identified. The composition and morphology of the collected dust particles appear to be similar to that of interplanetary dust particles.
Keywords :
fragmented particles
flocculent morphology
cometary nuclei
cosmic dust
interplanetary matter
meteorites
minerals
particle size
planetary composition
COmetary Secondary Ion Mass Analyser instrument data
ESA Rosetta mission
comet 67P/Churyumov-Gerasimenko coma
early-orbit phase
particle agglomerates
cometary nucleus
Sun
low impact speeds
particle sizes
submillimeter sizes
differential dust flux size distribution
power law exponent
dust particle elemental composition
silicates
olivine
pyroxenes
iron sulfides
sodium-to-iron elemental ratio
CI carbonaceous chondrites
organic matter
interplanetary dust particle morphology
dust particle fragments
Cited literature [49 references]
http://hal.in2p3.fr/in2p3-01291758
Contributor : Emilie Bonnardel Connect in order to contact the contributor
Submitted on : Tuesday, December 10, 2019 - 2:16:39 PM
Last modification on : Monday, December 13, 2021 - 9:16:50 AM
Long-term archiving on: : Wednesday, March 11, 2020 - 7:43:26 PM
Contributor : Emilie Bonnardel Connect in order to contact the contributor
Submitted on : Tuesday, December 10, 2019 - 2:16:39 PM
Last modification on : Monday, December 13, 2021 - 9:16:50 AM
Long-term archiving on: : Wednesday, March 11, 2020 - 7:43:26 PM
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