Related papers: Experiments on cometary activity: ejection of dust…
Comets are remnants of the icy planetesimals that formed beyond the ice line in the Solar Nebula. Growing from micrometre-sized dust and ice particles to km-sized objects is, however, difficult because of growth barriers and time scale…
Context. Cometary dust particles are subjected to various forces after being lifted off the nucleus. These forces define the dynamics of dust, trajectories, alignment, and fragmentation, which, in turn, have a significant effect on the…
Dust jets, i.e. fuzzy collimated streams of cometary material arising from the nucleus, have been observed in-situ on all comets since the Giotto mission flew by comet 1P/Halley in 1986. Yet their formation mechanism remains unknown.…
As comets journey into the inner solar system, they deliver particulates and volatile gases into their comae that reveal the most primitive materials in the solar system. Cometary dust particles provide crucial information for assessing the…
Beyond the snow line of protoplanetary discs and inside the dense core of molecular clouds, the temperature of gas is low enough for water vapour to condense into amorphous ices on the surface of preexisting refractory dust particles.…
Methods. We algorithmically tracked thousands of individual particles through four OSIRIS/NAC image sequences of 67P's near-nucleus coma. We then traced concentrated particle groups back to the nucleus surface, and estimated their potential…
Context. Comets are small celestial bodies made of ice, dust, and rock that orbit the Sun. Understanding their behavior as they warm up at perihelion unveils many pieces of information about the interior and general morphology of the ices…
The composition of cometary ices provides key information on the thermal and chemical properties of the outer parts of the protoplanetary disk where they formed 4.6 Gy ago. This chapter reviews our knowledge of composition of cometary comae…
Periodic comets of different dynamical groups with orbits at 2 - 5 AU still occasionally active. The observed dust activity of such objects can be connected with processes of water ice sublimation (MBCs) or crystallization of amorphous…
Ice naturally forms in the disordered or ``amorphous'' state when accreted from vapor at temperatures and pressures found in the interstellar medium and in the frigid, low density outer regions of the Sun's protoplanetary disk. It is…
We present OSIRIS/NAC observations of decimetre-sized, likely ice-containing aggregates ejected from a confined region on the surface of comet 67P/Churyumov-Gerasimenko. The images were obtained in January 2016 when the comet was at 2 AU…
Comets hold the key to the understanding of our solar system, its formation and its evolution, and to the fundamental plasma processes at work both in it and beyond it. A comet nucleus emits gas as it is heated by the sunlight. The gas…
Sublimative outgassing of comets produces torques that alter the rotation state of their nuclei. Recently, parameterized sublimative torque models have been developed to study rotation state changes of individual comet nuclei and…
In laboratory experiments, we study the motion of levitated, sedimenting clouds of sub-mm grains at low ambient pressure and at high solid-to-gas ratios $\epsilon$. The experiments show a collective behavior of particles, i.e. grains in…
The most successful model of comet dust presents comet particles as aggregates of submicron grains. It qualitatively explains the spectral and angular change in the comet brightness and polarization and is consistent with the thermal…
Comets are thought to preserve almost pristine dust particles, thus providing a unique sample of the properties of the early solar nebula. The microscopic properties of this dust played a key part in particle aggregation during the…
Photometric and spectroscopic observations of five nearly parabolic comets with eccentricity larger than 0.99 at heliocentric distances greater than 4 AU were performed. No molecular emission was observed for any studied comet and the…
Excess near-infrared emission is detected around one fifth of main-sequence stars, but its nature is a mystery. These excesses are interpreted as thermal emission from populations of small, hot dust very close to their stars (`hot…
Recently, there is much interest in droplet condensation on soft or liquid/liquid-like substrates. Droplets can deform soft and liquid interfaces resulting in a wealth of phenomena not observed on hard, solid surfaces (e.g., increased…
A new experimental set-up INterStellar Ice-Dust Experiment (INSIDE), was designed for studying cosmic grain analogues represented by ice-coated carbon- and silicate-based dust grains. In the new instrument, we can simulate physical and…