Search Publications
Alluvial Fan Morphology, distribution and formation on Titan
Hayes, A. G.; Birch, S. P. D.; Radebaugh, J. +2 more
Titan is a hydrologically active world, with dozens of alluvial fans that are evidence of sediment transport from high to low elevations. However, the distribution and requirements for the formation of fans on Titan are not well understood. We performed the first global survey of alluvial fans on Titan using Cassini Synthetic Aperture Radar (SAR) …
Titan's temporal evolution in stratospheric trace gases near the poles
Nixon, Conor A.; Achterberg, Richard K.; Flasar, F. Michael +7 more
We analyze spectra acquired by the Cassini/Composite Infrared Spectrometer (CIRS) at high resolution from October 2010 until September 2014 in nadir mode. Up until mid 2012, Titan's Northern atmosphere exhibited the enriched chemical content found since the Voyager days (November 1980), with a peak around the Northern Spring Equinox (NSE) in 2009.…
Geomorphological map of the Afekan Crater region, Titan: Terrain relationships in the equatorial and mid-latitude regions
Soderblom, Jason M.; Lorenz, Ralph D.; Turtle, Elizabeth P. +12 more
We carried out geomorphological mapping in a mid-latitude area surrounding the Afekan Crater region on Titan. We used Cassini RADAR (Synthetic Aperture Radar mode) data as the basemap, supplemented by Cassini RADAR microwave emissivity, Imaging Science Subsystem (ISS) infrared data, Visual and Infrared Mapping Spectrometer (VIMS) spectral images, …
Titan's "Magic Islands": Transient features in a hydrocarbon sea
Soderblom, Jason M.; Lorenz, Ralph D.; Malaska, Michael J. +6 more
The region of Titan's hydrocarbon sea, Ligeia Mare, where transient bright features were previously discovered, was anomalously bright in the first of two more recent Cassini RADAR observations but not the second. Another transient bright feature in a different region of Ligeia Mare was also discovered in the first of the new observations. Here we…
SPICAM observations and modeling of Mars aurorae
Bertaux, Jean-Loup; Stiepen, Arnaud; Gérard, Jean-Claude +4 more
Martian aurorae have been detected with the SPICAM instrument on board Mars Express both in the nadir and the limb viewing modes. In this study, we focus on three limb observations to determine both the altitudes and the intensities of the auroral emissions. The CO (a3Π-X1Σ) Cameron bands between 190 and 270 nm, the CO (A
Rhea gravity field and interior modeling from Cassini data analysis
Nimmo, Francis; Iess, Luciano; Jacobson, Robert A. +4 more
During its tour of the Saturn system, Cassini performed two close flybys of Rhea dedicated to gravity investigations, the first in November 2005 and the second in March 2013. This paper presents an estimation of Rhea's fully unconstrained quadrupole gravity field obtained from a joint multi-arc analysis of the two Cassini flybys.
Our best est…Photogeologic mapping and the geologic history of the Hellas basin floor, Mars
Hiesinger, H.; Bernhardt, H.; Ivanov, M. A. +3 more
The Hellas basin on Mars is the second-largest topographically well-defined impact structure in the Solar System and has repeatedly been interpreted as a major sink of volcanic, glacio-fluvial and eolian materials. Based on established guidelines for planetary mapping, we compiled a comprehensive photogeological map of Hellas Planitia, i.e., the H…
Cassini Imaging Science Subsystem observations of Titan's south polar cloud
West, R. A.; Rannou, P.; Lavvas, P. +5 more
In May of 2012 images of Titan obtained by the Cassini Imaging Science Subsystem (ISS) showed a newly-formed cloud patch near the southern pole. The cloud has unusual morphology and texture suggesting that it is formed by condensation at an altitude much higher than expected for any of the known organics in Titan's atmosphere. We measured the alti…
Venus' radar-bright highlands: Different signatures and materials on Ovda Regio and on Maxwell Montes
Treiman, Allan; Harrington, Elise; Sharpton, Virgil
Venus' highlands appear much brighter than its lowland plains in reflected radar, which has been explained by several conflicting hypotheses. We study this transition at higher spatial and elevation resolution than previously possible by combining Magellan synthetic aperture radar (SAR) images with Magellan SAR stereo elevations. We confirm that S…
Quasi-periodic injections of relativistic electrons in Saturn's outer magnetosphere
Krupp, N.; Dougherty, M. K.; Roussos, E. +8 more
Quasi-periodic, short-period injections of relativistic electrons have been observed in both Jupiter's and Saturn's magnetospheres, but understanding their origin or significance has been challenging, primarily due to the limited number of in-situ observations of such events by past flyby missions. Here we present the first survey of such injectio…