Search Publications
Episodic bright and dark spots on Uranus
Sromovsky, L. A.; Fry, P. M.; Hueso, R. +14 more
The northern mid-latitudes of Uranus produce greater episodes of bright cloud formation than any other region on the planet. Near 30°N, very bright cloud features were observed in 1999, 2004, and 2005, with lifetimes of the order of months. In October 2011, Gemini and HST observations revealed another unusually bright cloud feature near 23°N, whic…
Upper limits for H 2SO 4 in the mesosphere of Venus
Moriarty-Schieven, Gerald; Clancy, R. Todd; Sandor, Brad J.
Rapid temporal variability of SO 2 and SO in the Venus 85-100 km mesosphere ( Sandor, B.J., Clancy, R.T., Moriarty-Schieven G.H. [2007]. Bull. Am. Astron. Soc. 39, 503; Sandor, B.J., Clancy, R.T., Moriarty-Schieven, G.H., Mills, F.P. [2010]. Icarus 208, 49-60) requires in situ sources and sinks for these molecules. While many loss mecha…
Periglacial mass-wasting landforms on Mars suggestive of transient liquid water in the recent past: Insights from solifluction lobes on Svalbard
Hiesinger, H.; Hauber, E.; Johnsson, A. +4 more
On Earth, periglacial solifluction is a slow mass-wasting process related to freeze-thaw activity. We compare the morphology of small-scale lobate features on Mars to solifluction lobes in Svalbard to constrain their processes of formation. The analysis is based on high-resolution satellite imagery of Mars (HiRISE, ∼25 cm/pxl), aerial images of Sv…
Modeling specular reflections from hydrocarbon lakes on Titan
Nicholson, Philip D.; Sotin, Christophe; Barnes, Jason W. +9 more
During the 58th close flyby of Titan (T58), the Cassini Visual and Infrared Mapping Spectrometer (VIMS) observed a specular reflection of sunlight from Titan's Jingpo Lacus through the 5-µm methane window (Stephan, K. et al. [2010]. Geophys. Res. Lett. 37, L07104). The maximum intensity of this reflection is controlled by three basic factors…
The abundance and vertical distribution of the unknown ultraviolet absorber in the venusian atmosphere from analysis of Venus Monitoring Camera images
Esposito, Larry W.; Molaverdikhani, Karan; McGouldrick, Kevin
Observations of Venus using the ultraviolet filter of the Venus Monitoring Camera (VMC) on ESA's Venus Express Spacecraft (VEX) provide the best opportunity for study of the spatial and temporal distribution of the venusian unknown ultraviolet absorber since the Pioneer Venus (PV) mission. We compare the results of two sets of 125 radiative transf…
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 …