Search Publications
Elemental and molecular abundances in comet 67P/Churyumov-Gerasimenko
Mall, Urs; De Keyser, Johan; Hansen, Kenneth C. +18 more
Comets are considered to be some of the most pristine and unprocessed Solar system objects accessible to in situ exploration. Investigating their molecular and elemental composition takes us on a journey back to the early period of our Solar system and possibly even further. In this work, we deduce the bulk abundances of the major volatile species…
Ingredients for solar-like systems: protostar IRAS 16293-2422 B versus comet 67P/Churyumov-Gerasimenko
van Dishoeck, Ewine F.; Drozdovskaya, Maria N.; Jørgensen, Jes K. +2 more
Our modern day Solar System has 4.6 × 109 yr of evolution behind it with just a few relics of its birth conditions remaining. Comets are thought to be some of the most pristine tracers of the initial ingredients that were combined to produce the Earth and the other planets. Other low-mass protostars may be analogous to our proto-Sun and…
The Nucleus of comet 67P/Churyumov-Gerasimenko - Part I: The global view - nucleus mass, mass-loss, porosity, and implications
Tellmann, Silvia; Pätzold, Martin; Häusler, Bernd +7 more
The radio science experiment RSI on-board Rosetta determined the mass of the nucleus of comet 67P/Churyumov-Gerasimenko at the start of the prime mission from 2014 August to November (GM = 666.2 ± 0.2 m3 s-2 or 9982 ± 3 × 1012 kg) and shortly before the end of the mission from 2016 July to September (GM …
Surface localization of gas sources on comet 67P/Churyumov-Gerasimenko based on DFMS/COPS data
Altwegg, Kathrin; Rubin, Martin; Läuter, Matthias +1 more
We reconstruct the temporal evolution of the source distribution for the four major gas species H2O, CO2, CO, and O2 on the surface of comet 67P/Churyumov-Gerasimenko during its 2015 apparition. The analysis applies an inverse coma model and fits to data between 2014 August 6 and 2016 September 5 measured with the …
The refractory-to-ice mass ratio in comets
Blum, J.; Gundlach, B.; Mottola, S. +6 more
We review the complex relationship between the dust-to-gas mass ratio usually estimated in the material lost by comets, and the refractory-to-ice mass ratio inside the nucleus, which constrains the origin of comets. Such a relationship is dominated by the mass transfer from the perihelion erosion to fallout over most of the nucleus surface. This m…
Experimental phase function and degree of linear polarization of cometary dust analogues
Bertini, I.; Cremonese, G.; Lazzarin, M. +12 more
We present experimental phase function and degree of linear polarization curves for seven samples of cometary dust analogues namely: ground pieces of Allende, DaG521, FRO95002, and FRO99040 meteorites, Mg-rich olivine and pyroxene, and a sample of organic tholins. The experimental curves have been obtained at the IAA Cosmic Dust Laboratory at a wa…
On migration of dust and ice grains on the surface of the rotating comet nucleus
Wesołowski, M.; Gronkowski, P.; Tralle, I.
In the paper the migration of dust and ice grains over the surface of the comet nucleus is considered and analysed. This phenomenon is a consequence of interplay between the components of three forces tangential to the surface of comet nucleus and acting on the comet's grain. These forces are the gravity of the comet's nucleus, the frictional forc…
The backscattering ratio of comet 67P/Churyumov-Gerasimenko dust coma as seen by OSIRIS onboard Rosetta
Lara, L. M.; Bertaux, J. -L.; Lamy, P. +47 more
Remote sensing observations of dust particles ejected from comets provide important hints on the intimate nature of the materials composing these primitive objects. The measurement of dust coma backscattering ratio, BSR, defined as the ratio of the reflectance at phase angle 0° and 30°, helps tuning theoretical models aimed at solving the inverse …
A comparison between the two lobes of comet 67P/Churyumov-Gerasimenko based on D/H ratios in H2O measured with the Rosetta/ROSINA DFMS
De Keyser, Johan; Hansen, Kenneth C.; Gombosi, Tamas I. +13 more
The nucleus of the Jupiter-family comet 67P/Churyumov-Gerasimenko was discovered to be bi-lobate in shape when the European Space Agency spacecraft Rosetta first approached it in 2014 July. The bi-lobate structure of the cometary nucleus has led to much discussion regarding the possible manner of its formation and on how the composition of each lo…
Radical-assisted polymerization in interstellar ice analogues: formyl radical and polyoxymethylene
Duvernay, F.; Danger, G.; Chiavassa, T. +5 more
We present new laboratory experiments on the low-temperature formation of complex organic molecules (COMs) such as polyoxymethylene (POM), glycolaldehyde, ethylene glycol, and possibly glyceraldehyde and glycerol through radical-induced reactivity from vacuum ultraviolet (VUV) photolysis of formaldehyde in Ar and Xe matrices. The radical reactivit…