Search Publications
CO-driven Activity in Comet C/2017 K2 (PANSTARRS)
Chambers, Kenneth C.; Magnier, Eugene; Bauer, James +12 more
Comet C/2017 K2 (PANSTARRS) was discovered by the Pan-STARRS1 (PS1) Survey on 2017 May 21 at a distance of 16.09 au from the Sun, the second most distant discovery of an active comet. Pre-discovery images in the PS1 archive back to 2014 and additional deep CFHT images between 2013 May 10-13 showed the comet to be active at 23.75 au. We derive an u…
Formation of Methylamine and Ethylamine in Extraterrestrial Ices and Their Role as Fundamental Building Blocks of Proteinogenic α-amino Acids
Kaiser, Ralf I.; Förstel, Marko; Bergantini, Alexandre +2 more
The -CH-NH2 moiety represents the fundamental building block of all proteinogenic amino acids, with the cyclic amino acid proline being a special case (-CH-NH- in proline). Exploiting a chemical retrosynthesis, we reveal that methylamine (CH3NH2) and/or ethylamine (CH3CH2NH2) are es…
The Role of Pebble Fragmentation in Planetesimal Formation. II. Numerical Simulations
Blum, Jürgen; Johansen, Anders; Wahlberg Jansson, Karl +1 more
Some scenarios for planetesimal formation go through a phase of collapse of gravitationally bound clouds of millimeter- to centimeter-size pebbles. Such clouds can form, for example, through the streaming instability in protoplanetary disks. We model the collapse process with a statistical model to obtain the internal structure of planetesimals wi…
Impact of Radiogenic Heating on the Formation Conditions of Comet 67P/Churyumov-Gerasimenko
Wurz, P.; Altwegg, K.; Balsiger, H. +19 more
Because of the high fraction of refractory material present in comets, the heat produced by the radiogenic decay of elements such as aluminum and iron can be high enough to induce the loss of ultravolatile species such as nitrogen, argon, or carbon monoxide during their accretion phase in the protosolar nebula (PSN). Here, we investigate how heat …
Production of Sulfur Allotropes in Electron Irradiated Jupiter Trojans Ice Analogs
Ehlmann, Bethany L.; Brown, Michael E.; Choukroun, Mathieu +7 more
In this paper, we investigate sulfur chemistry in laboratory analogs of Jupiter Trojans and Kuiper Belt Objects (KBOs). Electron irradiation experiments of CH3OH-NH3-H2O and H2S-CH3OH-NH3-H2O ices were conducted to better understand the chemical differences between primor…
A New 3D Multi-fluid Dust Model: A Study of the Effects of Activity and Nucleus Rotation on Dust Grain Behavior at Comet 67P/Churyumov-Gerasimenko
Huang, Z.; Jia, X.; Fougere, N. +7 more
Improving our capability to interpret observations of cometary dust is necessary to deepen our understanding of the role of dust in the formation of comets and in altering the cometary environments. Models including dust grains are in demand to interpret observations and test hypotheses. Several existing models have taken into account the gas-dust…
Stability of Sulphur Dimers (S2) in Cometary Ices
Lunine, J. I.; Mousis, O.; Ronnet, T. +5 more
S2 has been observed for decades in comets, including comet 67P/Churyumov-Gerasimenko. Despite the fact that this molecule appears ubiquitous in these bodies, the nature of its source remains unknown. In this study, we assume that S2 is formed by irradiation (photolysis and/or radiolysis) of S-bearing molecules embedded in th…
Dynamic Deuterium Enrichment in Cometary Water via Eley-Rideal Reactions
Yao, Yunxi; Giapis, Konstantinos P.
The deuterium-to-hydrogen ratio (D/H) in water found in the coma of Jupiter family comet (JFC) 67P/Churyumov-Gerasimenko was reported to be (5.3 ± 0.7) × 10-4, the highest among comets and three times the value for other JFCs with an ocean-like ratio. This discrepancy suggests the diverse origins of JFCs and clouds the issue of the orig…