A first assessment of the strength of cometary particles collected in-situ by the COSIMA instrument onboard ROSETTA

Abstract

Soon after the arrival of the ROSETTA spacecraft at Comet 67/P Churyumov-Gerasimenko the onboard instrument COSIMA (“Cometary Secondary Ion Mass Analyzer”) collected a large number of cometary dust particles on targets from gold black of thickness between 10 and 30 μm. Inspection by its camera subsystem revealed that many of them consist of smaller units of typically some tens of micrometers in size. The collection process left the smaller dust particles in an essentially unaltered state whereas most particles larger than about 100 μm got fragmented into smaller pieces. Using the observed fragment size distributions, the present paper includes a first assessment of the strength for those dust particles that were disrupted upon impact

Dust particle flux and size distribution in the coma of 67P/Churyumov-Gerasimenko measured in situ by the COSIMA instrument on board Rosetta

“…The choice of using a constant density for all particles and not a size-dependent density as in Hornung et al (2016) is made to allow comparisons with the fluxes measured by other instruments since the use of a constant density is commonly assumed in the literature (see for example McDonnell et al 1987;Green et al 2004;Rotundi et al 2015). Expected variations in density from 100 kg/m 3 to 2500 kg/m 3 are taken into account to calculate the uncertainties in the mass.…”

“…The in situ collection of dust during the entire mission allows the study of the dust particle properties and their evolution along the orbit of the comet. Although COSIMA is mainly designed to measure the composition of the dust particles, its high efficiency in dust collection combined with the high resolution of the COSIMA internal camera (COSISCOPE) enables the investigation of the morphological properties of the particles (Schulz et al 2015;Hilchenbach et al 2016;Langevin et al 2016;Hornung et al 2016) and the evolution of the dust flux.…”

Space Weathering Induced Via Microparticle Impacts: 1. Modeling of Impact Velocities and Flux of Micrometeoroids From Cometary, Asteroidal, and Interstellar Origin in the Main Asteroid Belt and the Near‐Earth Environment

“…In particular, the type of large cometary dust grains that deposit most of the kinetic energy in our simulations would consist of fractal aggregates with high porosity (Fulle & Blum, ). Those aggregates fragment easily (Hornung et al, ) and are made of individual compact grains with a bulk density of 800 to 3,000 kg/m 3 (Fulle et al, ), whose mechanical properties are described in Hilchenbach et al ().…”

“…/2018JE005563 2017. Those aggregates fragment easily (Hornung et al, 2016) and are made of individual compact grains with a bulk density of 800 to 3,000 kg/m 3 (Fulle et al, 2015), whose mechanical properties are described in Hilchenbach et al (2017).…”

Cosmic dust VIII

“…Other papers covered the following topics: the physical and chemical properties of dust in the coma of 67P/C-G based on Rosetta/COSIMA's in-situ measurements by Martin Hilchenbach (Hornung et al, 2016); the dynamical properties of dust in the coma of 67P/C-G based on Rosetta/GIADA's in-situ measurements by Marco Fulle; a report on the latest results from the Rosetta/MIDAS experiment by Mark S. Bentley; an experimental study on the fragmentation, penetration, and consolidation of small bodies impacting on an asteroid by Akiko M. Nakamura; low-velocity impact experiments onto granular materials under reduced gravity conditions by Masato Kiuchi; a laboratory study on the infrared spectra of aggregate particles at a synchrotron facility by Akemi Tamanai; threedimensional molecular dynamics simulations of polydisperse charged dust particles in a gravitational field by Robert Botet; far-infrared AKARI observations of asteroidal dust bands in the zodiacal light by Takafumki Ootsubo; an improvement on the COBE/DIRBE model of zodiacal emission based on the AKARI mid-infrared all-sky maps by Toru Kondo; the characterization of regolith dust particles using the wavelength dependence of the opposition effect of airless bodies by Ludmilla Kolokolova; an analysis of the COBE/DIRBE, AKARI, and MIRIS data for the zodiacal light toward the ecliptic poles by Jeonghyun Pyo; the determination of the aliphatic-to-aromatic carbon abundance ratio for Solar System objects from their near-infrared spectra by Li Zhou; a numerical study on the contribution of high-energy photoelectrons to dust levitation above the surface of airless bodies by Hiroki Senshu.…”