Search Publications
Density and Charge of Pristine Fluffy Particles from Comet 67P/Churyumov-Gerasimenko
Lamy, P. L.; Szego, K.; Fulle, M. +38 more
The Grain Impact Analyzer and Dust Accumulator (GIADA) instrument on board ESA’s Rosetta mission is constraining the origin of the dust particles detected within the coma of comet 67 P/Churyumov-Gerasimenko (67P). The collected particles belong to two families: (i) compact particles (ranging in size from 0.03 to 1 mm), witnessing the presence of m…
Interstellar Detection of Methyl Isocyanate CH3NCO in Sgr B2(N): A Link from Molecular Clouds to Comets
Ziurys, L. M.; Halfen, D. T.; Ilyushin, V. V.
A new interstellar molecule, CH3NCO (methyl isocyanate), has been detected using the 12 m telescope of the Arizona Radio Observatory (ARO). CH3NCO was identified in spectra covering 48 GHz (68-116 GHz) in the 3 mm segment of a broadband survey of Sgr B2(N). Thirty very favorable rotational lines (Ka = 0 and Ka…
Molecular Oxygen in Oort Cloud Comet 1P/Halley
Altwegg, K.; Rubin, M.; van Dishoeck, E. F. +1 more
Recently, the ROSINA mass spectrometer suite on board the European Space Agency's Rosetta spacecraft discovered an abundant amount of molecular oxygen, O2, in the coma of Jupiter family comet 67P/Churyumov-Gerasimenko of O2/H2O = 3.80 ± 0.85%. It could be shown that O2 is indeed a parent species and that…
On the Electron-to-Neutral Number Density Ratio in the Coma of Comet 67P/Churyumov-Gerasimenko: Guiding Expression and Sources for Deviations
Edberg, N. J. T.; Vigren, E.; Galand, M. +3 more
We compute partial photoionization frequencies of H2O, CO2, and CO, the major molecules in the coma of comet 67P/Churyumov-Gerasimenko, the target comet of the ongoing ESA Rosetta mission. Values are computed from Thermosphere Ionosphere Mesosphere Energy and Dynamics/Solar EUV Experiment solar EUV spectra for 2014 August 1, …
Pits Formation from Volatile Outgassing on 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P.; Sierks, H. +8 more
We investigate the thermal evolution of comet 67P/Churyumov-Gerasimenko’s subsurface in the Seth_01 region, where active pits have been observed by the ESA/Rosetta mission. Our simulations show that clathrate destabilization and amorphous ice crystallization can occur at depths corresponding to those of the observed pits in a timescale shorter tha…
Rapid Temperature Changes and the Early Activity on Comet 67P/Churyumov-Gerasimenko
Alí-Lagoa, V.; Delbo', M.; Libourel, G.
The so-called “early activity” of comet 67P/Churyumov-Gerasimenko has been observed to originate mostly in parts of the concave region or “neck” between its two lobes. Since activity is driven by the sublimation of volatiles, this is a puzzling result because this area is less exposed to the Sun and is therefore expected to be cooler on average. W…
Prevailing Dust-transport Directions on Comet 67P/Churyumov-Gerasimenko
Kramer, Tobias; Noack, Matthias
Dust transport and deposition behind larger boulders on the comet 67P/Churyumov-Gerasimenko (67P/C-G) have been observed by the Rosetta mission. We present a mechanism for dust-transport vectors based on a homogeneous surface activity model incorporating in detail the topography of 67P/C-G. The combination of gravitation, gas drag, and Coriolis fo…
On the Possibility of Significant Electron Depletion due to Nanograin Charging in the Coma of Comet 67p/churyumov-gerasimenko near Perihelion
Wahlund, J. -E.; Vigren, E.; Galand, M. +2 more
We approach the complicated phenomena of gas-dust interactions in a cometary ionosphere, focusing in particular on the possibility of significant depletion in electron number density due to grain charging. Our one-dimensional ionospheric model, accounting for grain charging processes, is applied to the subsolar direction and the diamagnetic cavity…
A ∼32-70 K Formation Temperature Range for the Ice Grains Agglomerated by Comet 67 P/Churyumov-Gerasimenko
Altwegg, K.; Rubin, M.; Mousis, O. +4 more
Grand Canonical Monte Carlo simulations are used to reproduce the N2/CO ratio ranging between 1.7 × 10-3 and 1.6 × 10-2 observed in situ in the Jupiter-family comet 67 P/Churyumov-Gerasimenko (67 P) by the ROSINA mass spectrometer on board the Rosetta spacecraft. By assuming that this body has been agglomerated fro…