Search Publications
Enceladus's measured physical libration requires a global subsurface ocean
Burns, J. A.; Porco, C.; Tajeddine, R. +5 more
Several planetary satellites apparently have subsurface seas that are of great interest for, among other reasons, their possible habitability. The geologically diverse saturnian satellite Enceladus vigorously vents liquid water and vapor from fractures within a south polar depression and thus must have a liquid reservoir or active melting. However…
Titan's surface at 2.18-cm wavelength imaged by the Cassini RADAR radiometer: Results and interpretations through the first ten years of observation
Lorenz, R. D.; Janssen, M. A.; Hayes, A. G. +12 more
A comprehensive calibration and mapping of the thermal microwave emission from Titan's surface is reported based on radiometric data obtained at 2.18-cm wavelength by the passive radiometer included in the Cassini RADAR instrument. Compared to previous work, the present results incorporate the much larger data set obtained in the approximately ten…
The B-ring's surface mass density from hidden density waves: Less than meets the eye?
Nicholson, P. D.; Hedman, M. M.
Saturn's B ring is the most opaque ring in our Solar System, but many of its fundamental parameters, including its total mass, are not well constrained. Spiral density waves generated by mean-motion resonances with Saturn's moons provide some of the best constraints on the rings' mass density, but detecting and quantifying such waves in the B ring…
Nature, distribution, and origin of Titan's Undifferentiated Plains
Janssen, M. A.; Cassini RADAR Team; Lopes, Rosaly M. C. +15 more
The Undifferentiated Plains on Titan, first mapped by Lopes et al. (Lopes, R.M.C. et al., 2010. Icarus, 205, 540-588), are vast expanses of terrains that appear radar-dark and fairly uniform in Cassini Synthetic Aperture Radar (SAR) images. As a result, these terrains are often referred to as ;blandlands;. While the interpretation of several other…
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…
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…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…