Search Publications
On the thermal electron balance in Titan’s sunlit upper atmosphere
Strobel, D. F.; Wahlund, J. -E.; Ågren, K. +8 more
The Cassini mission has investigated Titan’s upper atmosphere in detail and found that, under solar irradiation, it has a well-developed ionosphere, which peaks between 1000 and 1200 km. In this paper we focus on the T40, T41, T42 and T48 Titan flybys by the Cassini spacecraft and use in situ measurements of N2 and CH4 densit…
Meteorology of Jupiter's equatorial hot spots and plumes from Cassini
Showman, Adam P.; Simon-Miller, Amy A.; Vasavada, Ashwin R. +1 more
We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their inter…
Saturn’s visible lightning, its radio emissions, and the structure of the 2009-2011 lightning storms
Porco, Carolyn C.; Dyudina, Ulyana A.; Ingersoll, Andrew P. +3 more
Visible lightning on Saturn was first detected by the Cassini camera in 2009 at ∼35° South latitude. We report more lightning observations at ∼35° South later in 2009, and lightning in the 2010-2011 giant lightning storm at ∼35° North. The 2009 lightning is detected on the night side of Saturn in a broadband clear filter. The 2011 lightning is det…
Saturn’s thermal emission at 2.2-cm wavelength as imaged by the Cassini RADAR radiometer
Baines, K. H.; Edgington, S. G.; Janssen, M. A. +7 more
We present well-calibrated, high-resolution maps of Saturn’s thermal emission at 2.2-cm wavelength obtained by the Cassini RADAR radiometer through the Prime and Equinox Cassini missions, a period covering approximately 6 years. The absolute brightness temperature calibration of 2% achieved is more than twice better than for all previous microwave…
Dications and thermal ions in planetary atmospheric escape
Simon Wedlund, C.; Ehrenreich, D.; Witasse, O. +4 more
In the recent years, the presence of dications in the atmospheres of Mars, Venus, Earth and Titan has been modeled and assessed. These studies also suggested that these ions could participate to the escape of the planetary atmospheres because a large fraction of them is unstable and highly energetic. When they dissociate, their internal energy is …
The density and temperature structure near the exobase of Saturn from Cassini UVIS solar occultations
Sandel, B. R.; Yelle, R. V.; Koskinen, T. T. +4 more
We analyzed 15 solar occultations observed by the Cassini UVIS instrument to constrain the density and temperature structure near the exobase of Saturn. We retrieved the density of H2 and thus the temperature at altitudes higher than 1900 km above the 1 bar level by analyzing the ionization continuum of H2 at wavelengths shor…
Comparing Dawn, Hubble Space Telescope, and ground-based interpretations of (4) Vesta
Nathues, Andreas; Russell, Christopher T.; Li, Jian-Yang +10 more
Observations of Asteroid (4) Vesta by NASA’s Dawn spacecraft are interesting because its surface has the largest range of albedo, color and composition of any other asteroid visited by spacecraft to date. These hemispherical and rotational variations in surface brightness and composition have been attributed to impact processes since Vesta’s forma…
Mineralogy of Mare Serenitatis on the near side of the Moon based on Chandrayaan-1 Moon Mineralogy Mapper (M3) observations
Bhattacharya, Satadru; Chauhan, Prakash; Kiran Kumar, A. S. +2 more
Spectral analysis of Mare Serenitatis has been carried out using Chandrayaan-1 Moon Mineralogy Mapper (M3) data in order to map the compositional diversity of the basaltic units that exist in the basin. Mare Serenitatis is characterized by multiple basaltic flows of different ages indicating a prolonged volcanism subsequent to the basin…
Impact of tidal heating on the onset of convection in Enceladus’s ice shell
Čadek, Ondřej; Tobie, Gabriel; Běhounková, Marie +1 more
By performing 3D simulations of thermal convection and tidal dissipation, we investigated the effect of tidal heating on the onset of convection in Enceladus’s ice shell. We considered a composite non-Newtonian rheology including diffusion, grain-size-sensitive and dislocation creeps, and we defined an effective tidal viscosity reproducing the dis…
Spectroscopic classification of icy satellites of Saturn I: Identification of terrain units on Dione
Stephan, K.; Capaccioni, F.; Cerroni, P. +4 more
Dione is one of the largest and densest icy satellites of Saturn. Its surface shows a marked asymmetry between its leading and trailing hemispheres, the leading side being brighter than the trailing side, which shows regions mantled by a dark veneer whose origin is likely exogenic. In order to identify different terrain units we applied the Spectr…