Article
Astronomy & Astrophysics
Jamie M. Jasinski, Mojtaba Akhavan-Tafti, Weijie Sun, James A. Slavin, Andrew J. Coates, Stephen A. Fuselier, Nick Sergis, Neil Murphy
Summary: The discovery of seven new flux transfer events (FTEs) at Saturn's dayside magnetopause reveals significant differences compared to typical FTEs found on Earth. FTEs at Saturn have smaller magnetic flux contents and are likely to grow primarily through adiabatic expansion.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
R. J. Wilson, D. B. Reisenfeld, P. A. Delamere, R. C. Allen, T. A. Cassidy
Summary: This study found that water group ions dominate the equatorial magnetosphere at Saturn, followed by ions with a mass to charge of 2 amu/q, and identified H-2(+) ions possibly originating from Titan.
Article
Astronomy & Astrophysics
L. A. Sromovsky, K. H. Baines, P. M. Fry
Summary: Saturn's north polar region experienced significant changes between 2012 and 2017, particularly in the color shift from dark blue/green to gold in the hexagon region, which can be attributed to alterations in aerosol layers. Spectral observations also revealed the presence of small bright cloud features in the ammonia cloud layer, with varying aerosol optical depths in different areas.
Article
Astronomy & Astrophysics
S. G. Jarmak, T. M. Becker, J. E. Colwell, R. G. Jerousek, L. W. Esposito
Summary: This article presents a dataset and high-level data products from the UVIS instrument on the Cassini spacecraft, which observed solar and stellar occultations to study Saturn's rings. The products include light curves, optical depth profiles, and provide insights into the properties of Saturn's rings.
Article
Geosciences, Multidisciplinary
C-J Yuan, E. Roussos, Y. Wei, N. Krupp, Y. X. Sun, Y. X. Hao
Summary: Using measurements from the Cassini spacecraft over 13 years, the study shows that the morphology of electron pitch angle distributions varies at different L-shells in Saturn's magnetosphere. Convective transport continues to govern at L = 3.5, while resonant interactions with waves may also play a key role in regulating dynamics in the core region of the radiation belts at smaller L-shells.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Astronomy & Astrophysics
Gianrico Filacchione, Mauro Ciarniello, Emiliano D'Aversa, Fabrizio Capaccioni, Roger N. Clark, Bonnie J. Buratti, Paul Helfenstein, Katrin Stephan, Christina Plainaki
Summary: Albedo, spectral slopes, and water ice band depths maps for the five midsized saturnian satellites have been derived from VIMS data. The maps help compare satellites' properties and study their variability with illumination conditions changes.
Article
Astronomy & Astrophysics
John M. Barbara, Anthony D. Del Genio
Summary: An study on the wind profiles and eddy momentum fluxes in the clouds of Saturn's southern hemisphere and equatorial region reveals changes in wind speed strength at different altitude levels, as well as convergence and divergence patterns of eddy momentum fluxes around the eastward and westward jets. The study also notes the challenges of verifying the strength of equatorial jets near the equator, as well as the increase in eddy convergence from the troposphere to the lower stratosphere and the divergence of eddy flux from the middle to the upper troposphere and stratosphere.
Article
Astronomy & Astrophysics
Ulrich Taubenschuss, Laurent Lamy, Georg Fischer, David Pisa, Ondrej Santolik, Jan Soucek, William S. Kurth, Baptiste Cecconi, Philippe Zarka, Helmut O. Rucker
Summary: This study analyzes the Faraday rotation effect detected in non-thermal radio emissions from Saturn, known as Saturn Kilometric Radiation (SKR), which mainly affects the lower-frequency part of SKR below 200 kHz. A statistical visibility analysis shows that elliptically polarized SKR from the dawn source regions is most likely to experience Faraday rotation along the ray path when beamed toward high latitudes.
Article
Astronomy & Astrophysics
Jian-zhao Wang, Zhuo-xi Huo, Lei Zhang
Summary: This study presents an empirical model of energetic electrons in Saturn's magnetosphere based on one-hour average data observed by the MIMI/LEMMS instrument onboard the Cassini spacecraft from 2004 to 2017. The model distinguishes between the inner and outer magnetosphere regions, incorporating dayside-nightside asymmetry and magnetodisk coordinates to capture the complexity of Saturn's magnetosphere. Comparison with SATRAD model highlights the utility of the new model in providing a comprehensive understanding of the energetic electron environment in Saturn's magnetosphere.
PLANETARY AND SPACE SCIENCE
(2021)
Article
Geochemistry & Geophysics
Peter L. Read, Arrate Antunano, Simon Cabanes, Greg Colyer, Teresa del Rio Gaztelurrutia, Agustin Sanchez-Lavega
Summary: Analysis of horizontal wind measurements in Saturn's polar regions reveals that eddies generally feed kinetic energy into the eastward and westward zonal mean jets, with the NPH wave being a significant contributor to the north polar jet.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Astronomy & Astrophysics
Benoit Seignovert, Pascal Rannou, Robert A. West, Sandrine Vinatier
Summary: This study presents a 13-year survey of haze UV extinction profiles in Titan's upper atmosphere, observing the evolution of the detached haze layer (DHL) at different latitudes. The DHL globally sunk and disappeared in 2012, re-emerging from the Northern hemisphere in late 2015. Variability of the DHL was observed in 2005, with slightly higher extinction on the dawn side and some local inhomogeneities during a 2009 polar flyby.
ASTROPHYSICAL JOURNAL
(2021)
Review
Astronomy & Astrophysics
Christophe Sotin, Klara Kalousova, Gabriel Tobie
Summary: The Cassini-Huygens mission revolutionized our understanding of Titan, the only known moon with a dense atmosphere and stable surface liquids, through exploration of the Saturn system from 2004 to 2017. It revealed Titan as an ocean world, with differentiation into a hydrosphere and rocky core. The presence of organic molecules synthesized and sedimented on Titan's surface, along with interactions between water, rock, and organics, have strong astrobiological implications. Further exploration by the Dragonfly mission and comparison with data from JUICE for Ganymede will reveal Titan's astrobiology potential.
ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES, VOL 49, 2021
(2021)
Article
Astronomy & Astrophysics
Julianne Moses, Zarah L. Brown, Tommi T. Koskinen, Leigh N. Fletcher, Joseph Serigano, Sandrine Guerlet, Luke Moore, J. Hunter Waite, Lotfi Ben-Jaffel, Marina Galand, Joshua M. Chadney, Sarah M. Horst, James A. Sinclair, Veronique Vuitton, Ingo Muller-Wodarg
Summary: During the Grand Finale stage of the Cassini mission, researchers discovered the flow of organic-rich ring material into Saturn's equatorial upper atmosphere. Through photochemical models, they studied the impact of this material on the composition of Saturn's atmosphere. However, observations did not confirm the predicted chemical consequences, leading to the conclusion that the ring influx may have been a transient event triggered by a recent dynamical event or that the material entered the atmosphere in the form of small dust particles.
Article
Geochemistry & Geophysics
J. Serigano, S. M. Horst, C. He, T. Gautier, R. Yelle, T. T. Koskinen, M. G. Trainer, M. J. Radke
Summary: The Cassini spacecraft's final orbits sampled Saturn's atmosphere and revealed complex mass spectra. The signals included native Saturn species and vaporized ices and higher mass organics believed to be flowing into Saturn's atmosphere from the rings. The analysis of the mass spectra showed that ring material was being deposited into Saturn's equatorial region at a rate of approximately 10(4) kg/s during these observations.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2022)
Article
Astronomy & Astrophysics
Zeqi Zhang, Ravindra T. Desai, Yohei Miyake, Hideyuki Usui, Oleg Shebanits
Summary: This study investigates the spacecraft-plasma interaction during Cassini's Grand Finale, revealing complex features like electron wings and spacecraft-scale vortices in the wake. The results show that a high concentration of negative ions and dust can drive the spacecraft to positive potentials, with electron properties and magnetic field orientation playing significant roles in determining the spacecraft potential.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
