Search Publications
Constraints on Saturn's tropospheric general circulation from Cassini ISS images
Del Genio, Anthony D.; Barbara, John M.
An automated cloud tracking algorithm is applied to Cassini Imaging Science Subsystem high-resolution apoapsis images of Saturn from 2005 and 2007 and moderate resolution images from 2011 and 2012 to define the near-global distribution of zonal winds and eddy momentum fluxes at the middle troposphere cloud level and in the upper troposphere haze. …
Microwave absorptivity by sulfuric acid in the Venus atmosphere: First results from the Venus Express Radio Science experiment VeRa
Pätzold, M.; Bird, M. K.; Häusler, B. +5 more
The Venus Express (VEX) Radio Science experiment VeRa utilizes radio occultation techniques to investigate the Venus atmosphere over a wide range of latitudes. Radio attenuation measurements with the VEX 3.6 cm (X-band) signal provide information on the absorptivity distribution within the Venus cloud deck. The combined results from 6 years of occ…
Latitudinal and altitudinal controls of Titan's dune field morphometry
Janssen, M. A.; Hayes, A. G.; Encrenaz, P. +5 more
Dune fields dominate ∼13% of Titan's surface and represent an important sink of carbon in the methane cycle. Herein, we discuss correlations in dune morphometry with altitude and latitude. These correlations, which have important implications in terms of geological processes and climate on Titan, are investigated through the microwave electromagne…
Mutual events in the Cold Classical transneptunian binary system Sila and Nunam
Buie, M. W.; Rabinowitz, D. L.; Grundy, W. M. +9 more
Hubble Space Telescope observations between 2001 and 2010 resolved the binary components of the Cold Classical transneptunian object (79360) Sila-Nunam (provisionally designated 1997 CS29). From these observations we have determined the circular, retrograde mutual orbit of Nunam relative to Sila with a period of 12.50995 ± 0.00036 days …
Circulation of the Venus upper mesosphere/lower thermosphere: Doppler wind measurements from 2001-2009 inferior conjunction, sub-millimeter CO absorption line observations
Moriarty-Schieven, Gerald; Clancy, R. Todd; Sandor, Brad J.
Sub-millimeter 12CO (346 GHz) and 13CO (330 GHz) line absorptions, formed within the mesospheric to lower thermospheric altitude (70-120 km) region of the Venus atmosphere, have been mapped across the nightside disk of Venus during 2001-2009 inferior conjunctions, employing the James Clerk Maxwell Telescope (JCMT). Radiative …
Disk-resolved photometry of Asteroid (2867) Steins
Jorda, L.; Lamy, P. L.; Keller, H. U. +2 more
We present a new method to perform disk-resolved photometry in order to investigate the intrinsic photometric properties of the surface of small Solar System bodies. We adopt the standard approach where a shape model is combined with a photometric formalism - in practise the Hapke formalism - to remove the effects of topography and recover the pho…
Radiative transfer analyses of Titan's tropical atmosphere
Tomasko, Martin G.; Griffith, Caitlin A.; Penteado, Paulo F. +2 more
Titan's optical and near-IR spectra result primarily from the scattering of sunlight by haze and its absorption by methane. With a column abundance of 92 km amagat (11 times that of Earth), Titan's atmosphere is optically thick and only ∼10% of the incident solar radiation reaches the surface, compared to 57% on Earth. Such a formidable atmosphere…
Geophysical evolution of Saturn's satellite Phoebe, a large planetesimal in the outer Solar System
Lunine, J. I.; Matson, D. L.; Johnson, T. V. +3 more
Saturn's satellite Phoebe is the best-characterized representative of large outer Solar System planetesimals, thanks to the close flyby by the Cassini spacecraft in June 2004. We explore the information contained in Phoebe's physical properties, density and shape, which are significantly different from those of other icy objects in its size range.…
Locations of thin liquid water layers on present-day Mars
Kereszturi, Akos; Rivera-Valentin, Edgard G.
CRISM indicates the presence of water ice patches in Richardson crater, located on Mars’ southern polar region at the area of the seasonal ice cap. Numerical simulations suggest that the maximum daytime temperature of the ice at these locations is between 195 and 220 K during local spring. Previous studies suggest that at these temperatures liquid…
Rheologies and ages of lava flows on Elysium Mons, Mars
Reiss, Dennis; Hiesinger, Harald; Pasckert, Jan Hendrik
We present results of our study of the rheologies and ages of lava flows in the Elysium Mons region of Mars. Previous studies have shown that the geometric dimensions of lava flows reflect rheological properties such as yield strength, effusion rate and viscosity. In this study the rheological properties of lava flows in the Elysium Mons region we…