Search Publications
Thermal desorption of circumstellar and cometary ice analogs
Martín-Doménech, R.; Muñoz Caro, G. M.; Bueno, J. +1 more
Context. Thermal annealing of interstellar ices takes place in several stages of star formation. Knowledge of this process comes from a combination of astronomical observations and laboratory simulations under astrophysically relevant conditions.
Aims: For the first time we present the results of temperature programmed desorption (TPD) experi…
The rotation state of 67P/Churyumov-Gerasimenko from approach observations with the OSIRIS cameras on Rosetta
Jorda, L.; Lamy, P. L.; Bertaux, J. -L. +46 more
Aims: Approach observations with the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) experiment onboard Rosetta are used to determine the rotation period, the direction of the spin axis, and the state of rotation of comet 67P's nucleus.
Methods: Photometric time series of 67P have been acquired by OSIRIS since the pos…
Formation of pebble-pile planetesimals
Johansen, Anders; Wahlberg Jansson, Karl
Asteroids and Kuiper belt objects are remnant planetesimals from the epoch of planet formation. The first stage of planet formation is the accumulation of dust and ice grains into mm- and cm-sized pebbles. These pebbles can clump together through the streaming instability and form gravitationally bound pebble clouds. Pebbles inside such a cloud wi…
Methanol along the path from envelope to protoplanetary disc
Walsh, Catherine; Harsono, Daniel; van Dishoeck, Ewine F. +2 more
Interstellar methanol is considered to be a parent species of larger, more complex organic molecules. A physicochemical simulation of infalling parcels of matter is performed for a low-mass star-forming system to trace the chemical evolution from cloud to disc. An axisymmetric 2D semi-analytic model generates the time-dependent density and velocit…
Plasma environment of a weak comet - Predictions for Comet 67P/Churyumov-Gerasimenko from multifluid-MHD and Hybrid models
Altwegg, K.; Glassmeier, K. -H.; Richter, I. +8 more
The interaction of a comet with the solar wind undergoes various stages as the comet's activity varies along its orbit. For a comet like 67P/Churyumov-Gerasimenko, the target comet of ESA's Rosetta mission, the various features include the formation of a Mach cone, the bow shock, and close to perihelion even a diamagnetic cavity. There are differe…
Astra: Interdisciplinary study on enhancement of the end-to-end accuracy for spacecraft tracking techniques
Iess, Luciano; Tortora, Paolo; Di Benedetto, Mauro +3 more
Navigation of deep-space probes is accomplished through a variety of different radio observables, namely Doppler, ranging and Delta-Differential One-Way Ranging (Delta-DOR). The particular mix of observations used for navigation mainly depends on the available on-board radio system, the mission phase and orbit determination requirements. The accur…
Temperature dependence of the sublimation rate of water ice: Influence of impurities
Kossacki, Konrad J.; Leliwa-Kopystynski, Jacek
The sublimation rate of ice is commonly calculated using the simple Hertz-Knudsen formula. This formula is derived from the kinetic theory of gases and ignores microphysical processes determining the actual sublimation rate. The microphysical processes can be accounted for by including the temperature dependent sublimation coefficient (Kossacki, K…
How to link the relative abundances of gas species in coma of comets to their initial chemical composition?
Marboeuf, Ulysse; Schmitt, Bernard
Comets are expected to be the most primitive objects in the Solar System. The chemical composition of these objects 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 of the coma, the outgassing p…
An Early Look of Comet C/2013 A1 (Siding Spring): Breathtaker or Nightmare?
Ye, Quan-Zhi; Hui, Man-To
The dynamically new comet, C/2013 A1 (Siding Spring), is to make a close approach to Mars on 2014 October 19 at 18:30 UT at a distance of 40 ± 1 Martian radii. Such an extremely rare event offers a precious opportunity for the spacecrafts on Mars to closely study a dynamically new comet itself as well as the planet-comet interaction. Meanwhile, th…
Giada: its Status after the Rosetta Cruise Phase and On-Ground Activity in Support of the Encounter with Comet 67P/CHURYUMOV-GERASIMENKO
Lamy, P.; Fulle, M.; Rodrigo, R. +33 more
GIADA (Grain Impact Analyser and Dust Accumulator) on-board the Rosetta mission to comet 67P/Churyumov-Gerasimenko was designed to study the physical and dynamical properties of dust particles ejected by the comet during the encounter. In this paper we report the results of the analysis of data collected by GIADA during the past seven years of the…