Related papers: Cometary ion dynamics at 67P: A collisional test-p…
ESA's Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko (67P) was the first mission that accompanied a comet over a substantial fraction of its orbit. On board was the ROSINA mass spectrometer suite to measure the local densities of the…
Reproducing the observed activity of comets with thermophysical models remains a primary challenge of cometary science. We use a pebble-based thermophysical model of gas-pressure build-up in the subsurface to reproduce the global emission…
Context: The dust-brightness phase curves that have been measured by the OSIRIS cameras on board the Rosetta spacecraft within the coma of comet 67P/Churyumov-Gerasimenko (67P) present a remarkable u-shape. Aims: Our goal is to compare…
As the ESA Rosetta mission approached, orbited, and sent a lander to comet 67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based observations also followed the comet. We constrain the total activity level of the comet by…
The chemical composition of comets is frequently assumed to be directly provided by the observations of the abundances of volatile molecules in the coma. The present work aims to determine the relationship between the chemical composition…
We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until…
Aims. We use four observational data sets, mainly from the Rosetta mission, to constrain the activity pattern of the nucleus of comet 67P/Churyumov-Gerasimenko. Methods. We develop a numerical model that computes the production rate and…
We report on the detection of three icy cavities on the nucleus of comet 67P/Churyumov-Gerasimenko. They were identified on high-resolution anaglyphs built from images acquired by the OSIRIS instrument aboard the Rosetta spacecraft on 2016…
On November 12, 2014, the ESA/Rosetta descent module Philae landed on the Abydos site of comet 67P/Churyumov-Gerasimenko. Aboard this module, the Ptolemy mass spectrometer measured a CO/CO2 ratio of 0.07 +/- 0.04 which differs substantially…
Transport properties of high-energy-density plasmas are influenced by the ion collision rate. Traditionally, this rate involves the Coulomb logarithm, $\ln\Lambda$. Typical values of $\ln\Lambda$ are $\approx 10~\mbox{to}~20$ in kinetic…
We study ionization and transport processes in partially ionized multicomponent plasmas. The plasma composition is calculated via a system of coupled mass action laws. The electronic transport properties are determined by the electron-ion…
The Alice ultraviolet spectrograph on the European Space Agency Rosetta spacecraft observed comet 67P/Churyumov-Gerasimenko in its orbit around the Sun for just over two years. Alice observations taken in 2015 October, two months after…
In an earlier study, we reported that the ram gauge of the COmet Pressure Sensor (COPS), one of the three instruments of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), could be used to obtain information about the…
Context. Comets are primitive objects, remnants of the volatile-rich planetesimals from which the solar system condensed. Knowing their structure and composition is thus crucial for the understanding of our origins. After the successful…
The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) suite of instruments operated throughout the over two years of the Rosetta mission operations in the vicinity of comet 67P/Churyumov-Gerasimenko. It measured gas…
We present 2-5 $\mu$m spectroscopic observations of the dust coma of 67P/Churyumov-Gerasimenko obtained with the VIRTIS-H instrument onboard Rosetta during two outbursts that occurred on 2015, 13 September 13.6 h UT and 14 September 18.8 h…
The structure of cometary dust is a tracer of growth processes in the formation of planetesimals. Instrumentation on board the Rosetta mission to comet 67P/Churyumov- Gerasimenko captured dust particles and analysed them in situ. However,…
Interchange drive and cross-field transport of density filaments in quasi-neutral inhomogeneously magnetized electron-positron plasmas is shown to be strongly reduced by the presence of minority ions. Two mechanisms are identified for the…
The Alice ultraviolet spectrograph on board the \textit{Rosetta} orbiter provided the first near-nucleus ultraviolet observations of a cometary coma from arrival at comet 67P/Churyumov-Gerasimenko in 2014 August through 2016 September. The…
Context. The Rosetta spacecraft made continuous measurements of the coma of comet 67P/ Churyumov-Gerasimenko (67P) for more than two years. The plasma in the coma appeared very dynamic, and many factors control its variability. Aims. We…