Search Publications
Interpretation of the Phase Functions Measured by the OSIRIS Instrument for Comet 67P/Churyumov-Gerasimenko
Muinonen, Karri; Agarwal, Jessica; Penttilä, Antti +2 more
We show that the scattering phase functions of the coma and the nucleus of the comet 67P/Churyumov-Gerasimenko measured by the Rosetta/Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) instrument can be reproduced by a particle model involving clustered, densely packed submicrometer-sized grains composed of organic material and l…
Noble Gas Abundance Ratios Indicate the Agglomeration of 67P/Churyumov-Gerasimenko from Warmed-up Ice
Wurz, P.; Lunine, J. I.; Danger, G. +8 more
The origin of cometary volatiles remains a major open question in planetary science. Comets may have either agglomerated from crystalline ices condensed in the protosolar nebula (PSN) or from amorphous ice originating from the molecular cloud and interstellar medium. Here, based on the recent argon, krypton, and xenon measurements performed by the…
High-resolution SOFIA/EXES Spectroscopy of SO2 Gas in the Massive Young Stellar Object MonR2 IRS3: Implications for the Sulfur Budget
Montiel, Edward; Neufeld, David A.; Blake, Geoffrey A. +10 more
Sulfur has been observed to be severely depleted in dense clouds leading to uncertainty in the molecules that contain it and the chemistry behind their evolution. Here, we aim to shed light on the sulfur chemistry in young stellar objects (YSOs) by using high-resolution infrared spectroscopy of absorption by the ν 3 rovibrational band o…
Evolution of Cometary Dust Particles to the Orbit of the Earth: Particle Size, Shape, and Mutual Collisions
Ishiguro, Masateru; Yang, Hongu
In this study, we numerically investigated the orbital evolution of cometary dust particles, with special consideration of the initial size-frequency distribution (SFD) and different evolutionary tracks according to the initial orbit and particle shape. We found that close encounters with planets (mostly Jupiter) are the dominating factor determin…
Synthesis of Molecular Oxygen via Irradiation of Ice Grains in the Protosolar Nebula
Wurz, P.; Lunine, J. I.; Danger, G. +4 more
Molecular oxygen has been detected in the coma of comet 67P/Churyumov-Gerasimenko with a mean abundance of 3.80 ± 0.85% by the ROSINA mass spectrometer on board the Rosetta spacecraft. To account for the presence of this species in comet 67P/Churyumov-Gerasimenko, it has been shown that the radiolysis of ice grain precursors of comets is a viable …
Thermal Reaction in Cometary and Pre-cometary Ices: Formation of Thiocarbamate in OCS-CH3NH2 Mixed Ices
Hodyss, Robert; Mahjoub, Ahmed
Cometary ices are rich sources of organic molecules relevant to prebiotic chemistry and may have played a key role in the delivery of the building blocks of life to Earth. Comets endure thermal processing of their surfaces during their orbits around the Sun. Furthermore, icy grain precursors of cometary materials may have experienced heating in th…
Limits on the Contribution of Endogenic Radiolysis to the Presence of Molecular Oxygen in Comet 67P/Churyumov-Gerasimenko
Mousis, Olivier; Bouquet, Alexis; Nicolaou, Georgios +6 more
Radiolytic production has been proposed as a potential source for the molecular oxygen observed in comet 67P/Churyumov-Gerasimenko. Radiolysis can be exogenic or endogenic, the latter due to radionuclides present in the dust constitutive of the comet nucleus. We investigated the possibility of forming a significant amount of molecular oxygen throu…