Results 81 to 90 of about 4,877 (221)

Gas Sources from the Coma and Nucleus of Comet 46P/Wirtanen Observed Using ALMA

The Astrophysical Journal, 2023
Gas-phase molecules in cometary atmospheres (comae) originate primarily from (1) outgassing by the nucleus, (2) sublimation of icy grains in the near-nucleus coma, and (3) coma (photo)chemical processes.
M. A. Cordiner, N. X. Roth, S. N. Milam, G. L. Villanueva, D. Bockelée-Morvan, A. J. Remijan, S. B. Charnley, N. Biver, D. C. Lis, C. Qi, B. P. Bonev, J. Crovisier, J. Boissier   +12 more
doaj   +1 more source

The Composition of Comets

, 2015
This paper is the result of the International Cometary Workshop, held in Toulouse, France in April 2014, where the participants came together to assess our knowledge of comets prior to the ESA Rosetta Mission. In this paper, we look at the composition of
Biver, Nicolas, Bockelee-Morvan, Dominique, Charnley, Steven B., Cochran, Anita L., Cordiner, Martin, Gicquel, Adeline, Hadamcik, Edith, Kuan, Yi-Jehng, Lasue, Jeremie, Levasseur-Regourd, Anny-Chantal, Mumma, Michael J., Paganini, Lucas, Schleicher, David G.   +12 more
core   +3 more sources

Deciphering the “Missing Xenon Paradox” in Celestial Bodies: A Multifaceted Perspective Toward Demystifying This Enigma

Journal of Geophysical Research: Planets, Volume 131, Issue 4, April 2026.
Abstract Xenon (Xe) is a heavy noble gas with intriguing chemical properties, such as having several stable isotopes and the ability to form compounds under extreme conditions. Despite the predictions based on cosmochemical models that suggest xenon should be relatively abundant in planetary reservoirs, empirical data indicate a significant depletion ...
Avinash Kumar Both, Avradip Ghosh, Chin Li Cheung   +2 more
wiley   +1 more source

Physical Properties of Frozen Volatiles—Their Relevance to the Study of Comet Nuclei [PDF]

International Astronomical Union Colloquium, 1989
AbstractThe structural and thermodynamical properties of water ice and ice mixtures containing CO, CO2, CH4, and NH3 are thought to be important for the evolution of cometary nuclei. Based on recent laboratory studies performed by several groups, an overview is given of the properties of various ices condensed at low temperatures and of their evolution
openaire   +1 more source

Covertly Active Comet (139359) 2001 ME1

The Planetary Science Journal
On 2018 November 18, coronagraphs onboard the Solar and Heliospheric Observatory (SOHO) captured an unrecognized comet crossing its fields of view. We identified this comet to be the minor planet (139359) 2001 ME _1 , whose previously unnoticed dust ...
Qicheng Zhang, Quanzhi Ye, Karl Battams, Matthew M. Knight, Worachate Boonplod, Rainer Kracht   +5 more
doaj   +1 more source

Thermal Evolution of the Sulfur‐Rich, Small Terrestrial Planetary Core as Inferred From the Experimental Study of the Fe‐S‐O‐H System

Journal of Geophysical Research: Planets, Volume 131, Issue 4, April 2026.
Abstract The cores of rocky planets, including the Earth, are believed to contain light elements such as silicon, oxygen, sulfur, hydrogen, and carbon. Amongst them, sulfur appears to be rich in the cores of small terrestrial bodies like Mars and Ganymede. To understand the evolution of sulfur‐rich cores in the presence of other light elements, we have
Jeongmin Lee, Jaeyoon Keum, Taehyun Kim, Chanbi Lee, Stella Chariton, Vitali Prakapenka, Nico Giordano, Byungdal So, Huijeong Hwang, Yongjae Lee   +9 more
wiley   +1 more source

Evidence for Abiotic Dimethyl Sulfide in Cometary Matter

The Astrophysical Journal
Technological progress related to astronomical observatories such as the recently launched James Webb Space Telescope (JWST) allows searching for signs of life beyond our solar system, namely, in the form of unambiguous biosignature gases in exoplanetary
Nora Hänni, Kathrin Altwegg, Michael Combi, Stephen A. Fuselier, Johan De Keyser, Niels F. W. Ligterink, Martin Rubin, Susanne F. Wampfler   +7 more
doaj   +1 more source

Water production rates and activity of interstellar comet 2I/Borisov

, 2020
We observed the interstellar comet 2I/Borisov using the Neil Gehrels-Swift Observatory's Ultraviolet/Optical Telescope. We obtained images of the OH gas and dust surrounding the nucleus at six epochs spaced before and after perihelion (-2.56 AU to 2.54 ...
Bannister, Michele T., Bodewits, Dennis, Noonan, John, Xing, Zexi   +3 more
core   +1 more source

Fractal Dimensions of Venusian Lava Flows: New Findings for Atla Regio and Review of Previous Analyses

Journal of Geophysical Research: Planets, Volume 131, Issue 4, April 2026.
Abstract The fractal dimensions of lava flow margins on Earth often correlate with their flow morphologies and have been used to tentatively identify flow morphology on other rocky planets where fine‐scale observations are limited. Previous studies of lava flow margins on Venus have reported fractal dimensions (D) mostly within the range between 1.05 ...
E. M. Recchuiti, V. Haag, D. R. Bohnenstiehl, A. Soldati   +3 more
wiley   +1 more source

Comets, volcanism, the salt-rich regolith, and cycling of volatiles on Mars [PDF]

Icarus, 1987
Abstract Estimates of the total inventory of the volatile elements C, H, O, and N on Mars, based upon atmospheric gas tracers, vary by a factor of 25 among different authors. Accretion of comets as the source of volatiles can account for less than 5% of the actual inventory, assuming the chondritic S/Cl abundance ratio in comets and a Martian ...
openaire   +1 more source