Search Publications
A non-energetic mechanism for glycine formation in the interstellar medium
van Dishoeck, E. F.; Kofman, V.; Ioppolo, S. +8 more
The detection of the amino acid glycine and its amine precursor methylamine on the comet 67P/Churyumov-Gerasimenko by the Rosetta mission provides strong evidence for a cosmic origin of amino acids on Earth. How and when such molecules form along the process of star formation remains debated. Here we report the laboratory detection of glycine form…
Prestellar grain-surface origins of deuterated methanol in comet 67P/Churyumov-Gerasimenko
De Keyser, Johan; van Dishoeck, Ewine F.; Drozdovskaya, Maria N. +6 more
Deuterated methanol is one of the most robust windows astrochemists have on the individual chemical reactions forming deuterium-bearing molecules and the physicochemical history of the regions where they reside. The first-time detection of mono- and di-deuterated methanol in a cometary coma is presented for comet 67P/Churyumov-Gerasimenko using Ro…
Formation of Phosphorus Monoxide (PO) in the Interstellar Medium: Insights from Quantum-chemical and Kinetic Calculations
Jiménez-Serra, Izaskun; Roncero, Octavio; García de la Concepción, Juan +2 more
In recent years, phosphorus monoxide (PO), an important molecule for prebiotic chemistry, has been detected in star-forming regions and in the comet 67P/Churyumov-Gerasimenko. These studies have revealed that, in the interstellar medium (ISM), PO is systematically the most abundant P-bearing species, with abundances that are about one to three tim…
First Comet Observations with NIRSPEC-2 at Keck: Outgassing Sources of Parent Volatiles and Abundances Based on Alternative Taxonomic Compositional Baselines in 46P/Wirtanen
Villanueva, Geronimo L.; Cochran, Anita L.; Bodewits, Dennis +18 more
A major upgrade to the NIRSPEC instrument at the Keck II telescope was successfully completed in time for near-infrared spectroscopic observations of comet 46P/Wirtanen during its exceptionally close flyby of Earth in 2018 December. These studies determined the abundances of several volatiles, including C2H2, C2H
Airfall on Comet 67P/Churyumov-Gerasimenko
Zacny, Kris; Bodewits, Dennis; Vincent, Jean-Baptiste +11 more
We here study the transfer process of material from one hemisphere to the other (deposition of airfall material) on an active comet nucleus, specifically 67P/Churyumov-Gerasimenko. Our goals are to: 1) quantify the thickness of the airfall debris layers and how it depends on the location of the target area, 2) determine the amount of H2…
Iron and nickel atoms in cometary atmospheres even far from the Sun
Jehin, E.; Manfroid, J.; Hutsemékers, D.
In comets, iron and nickel are found in refractory dust particles or in metallic and sulfide grains1. So far, no iron- or nickel-bearing molecules have been observed in the gaseous coma of comets2. Iron and a few other heavy atoms, such as copper and cobalt, have been observed only in two exceptional objects: the Great Comet …
D/H in the refractory organics of comet 67P/Churyumov-Gerasimenko measured by Rosetta/COSIMA
Hilchenbach, M.; Merouane, S.; Engrand, C. +11 more
The D/H ratio is a clue to the origin and evolution of hydrogen-bearing chemical species in Solar system materials. D/H has been observed in the coma of many comets, but most such measurements have been for gaseous water. We present the first in situ measurements of the D/H ratios in the organic refractory component of cometary dust particles coll…
Cold Traps of Hypervolatiles in the Protosolar Nebula at the Origin of the Peculiar Composition of Comet C/2016 R2 (PanSTARRS)
Mousis, Olivier; Aguichine, Artyom; Bouquet, Alexis +4 more
Recent observations of the long-period comet C/2016 R2 (PanSTARRS; hereafter R2) indicate an unusually high N2/CO abundance ratio, typically larger than ∼0.05, and at least 2-3 times higher than the one measured in 67P/Churyumov-Gerasimenko. Another striking compositional feature of this comet is its heavy depletion in H2O (H…
Cyanogen, cyanoacetylene, and acetonitrile in comet 67P and their relation to the cyano radical
Altwegg, K.; Balsiger, H.; Fuselier, S. A. +6 more
The cyano radical (CN) is one of the most frequently remotely observed species in space, and is also often observed in comets. Data for the inner coma of comet 67P/Churyumov-Gerasimenko collected by the high-resolution Double Focusing Mass Spectrometer (DFMS) on board the Rosetta orbiter revealed an unexpected chemical complexity, and, recently, a…
The effect of varying porosity and inhomogeneities of the surface dust layer on the modelling of comet gas production
Skorov, Yuri; Reshetnyk, Volodymyr; Blum, Jürgen +3 more
We study how uncertainties in knowledge of the microstructure of the porous dust surface layer affect our estimates of effective gas production of comet 67P/Churyumov-Gerasimenko. We analyse the transport properties (distribution of free paths, mean pore size, permeability) for random densely packed porous layers. Bimodal layers, as well as variou…