Search Publications
Detection and mapping of hydrocarbon deposits on Titan
Nicholson, Philip D.; Sotin, Christophe; Barnes, Jason W. +13 more
We report the identification of compounds on Titan's surface by spatially resolved imaging spectroscopy methods through Titan's atmosphere, and set upper limits to other organic compounds. We present evidence for surface deposits of solid benzene (C6H6), solid and/or liquid ethane (C2H6), or methane (CH<…
Mountains on Titan: Modeling and observations
Showman, Adam P.; Lopes, Rosaly M. C.; Radebaugh, Jani +5 more
We have developed a thermal model of Titan's interior to study changes in volume during partial freezing or melting of a subsurface ocean due to heat flux variations from the interior. We find that the long-term cooling of Titan can cause global volume contraction ΔV/V ∼0.01. We then simulate two-dimensional contractional deformation of Titan's ic…
Bathymetry and absorptivity of Titan's Ontario Lacus
Callahan, P.; Hayes, A. G.; Kirk, R. L. +9 more
Ontario Lacus is the largest and best characterized lake in Titan's south polar region. In June and July 2009, the Cassini RADAR acquired its first Synthetic Aperture Radar (SAR) images of the area. Together with closest approach altimetry acquired in December 2008, these observations provide a unique opportunity to study the lake's nearshore bath…
Coupling mantle convection and tidal dissipation: Applications to Enceladus and Earth-like planets
Čadek, Ondřej; Tobie, Gabriel; Běhounková, Marie +1 more
Anelastic dissipation of tidal forces likely contributes to the thermal budget of several satellites of giant planets and Earth-like planets closely orbiting other stars. In order to address how tidal heating influences the thermal evolution of such bodies, we describe here a new numerical tool that solves simultaneously mantle convection and tida…
Saturn's emitted power
Fletcher, Leigh N.; West, Robert A.; Porco, Carolyn C. +18 more
Long-term (2004-2009) on-orbit observations by Cassini Composite Infrared Spectrometer are analyzed to precisely measure Saturn's emitted power and its meridional distribution. Our evaluations suggest that the average global emitted power is 4.952 ± 0.035 W m-2 during the period of 2004-2009. The corresponding effective temperature is 9…
A sensitivity study of the Enceladus torus
Delamere, P. A.; Bagenal, F.; Fleshman, B. L.
We have developed a homogeneous model of physical chemistry to investigate the neutral-dominated, water-based Enceladus torus. Electrons are treated as the summation of two isotropic Maxwellian distributions: a thermal component and a hot component. The effects of electron impact, electron recombination, charge exchange, and photochemistry are inc…
Geophysical implications of the long-wavelength topography of Rhea
Asmar, S. W.; Nimmo, F.; Thomas, P. C. +1 more
We use limb profiles to investigate the long-wavelength topography and topographic variance spectrum of Rhea. One-dimensional variance spectra show a break in slope at a wavelength of ≈300 km; a similar effect is seen on the Moon and may be a signature of an elastic lithosphere having a thickness Te ≈ 10 km. The implied heat flux is ∼15…
Upper limits on Titan's magnetic moment and implications for its interior
Russell, C. T.; Wei, H. Y.; Dougherty, M. K. +2 more
Measurements from the Cassini spacecraft reveal a largely magnetized ionosphere of Titan whose low-altitude fields could be from the interior of Titan or from penetrating external fields. We use the Cassini magnetic field measurements obtained during 25 Titan flybys to examine the upper limit of Titan's internal magnetic moment. The radial compone…
Suppression of the Rhines effect and the location of vortices on Saturn
Showman, A. P.; Penny, A. B.; Choi, D. S.
Saturn's atmosphere contains numerous vortices that reside predominantly within specific localized latitude bands. Two-dimensional turbulence theory predicts that vortices which do form are readily destroyed as they interact with dispersive Rossby waves in a process called the “Rhines effect,” which acts to organize turbulent energy into alternati…