Search Publications
Modeling the effect of atmospheric gravity waves on Saturn's ionosphere
Matcheva, Katia I.; Barrow, Daniel J.
Cassini's radio occultations by Saturn reveal a highly variable ionosphere with a complex vertical structure often dominated by several sharp layers of electrons. The cause of these layers has not yet been satisfactorily explained. This paper demonstrates that the observed system of layers in Saturn's lower ionosphere can be explained by the prese…
Jupiter's Great Red Spot: Fine-scale matches of model vorticity patterns to prevailing cloud patterns
Dowling, Timothy E.; Morales-Juberías, Raúl
We report on a set of six new matches between fine-scale features in the vorticity field of a three-dimensional (3D), primitive-equation, finite-difference model of Jupiter's Great Red Spot that includes no clouds or cloud physics, and quasi-permanent structures in reflected visible-band images of the clouds. These add to similar success by Cho et…
Using THEMIS data to resolve the discrepancy between CRISM/OMEGA and TES modeled phyllosilicate abundance in Mawrth Vallis
Moersch, Jeffrey E.; Viviano, Christina E.
We explore the effects of spatial resolution on the detectability of phyllosilicates in the thermal infrared dataset from the Mars Global Surveyor Thermal Emission Spectrometer (TES). Data from the Mars Odyssey THermal Emission Imaging System (THEMIS) instrument is used to resolve spatial resolution driven discrepancies between detection of phyllo…
Energetic particle measurements in the vicinity of Dione during the three Cassini encounters 2005-2011
Krupp, N.; Roussos, E.; Khurana, K. K. +7 more
The Cassini spacecraft encountered the moon Dione three times between 2005 and 2011. During the flybys particles and fields measurements have been performed and used to study the magnetospheric interaction between the fourth largest moon in the saturnian system and the surrounding magnetospheric plasma. Here we present the results of the Low Energ…
An updated rotation model for Comet 9P/Tempel 1
Li, J. -Y.; Harris, A. W.; Veverka, J. +8 more
Observations from the second encounter of Comet 9P/Tempel 1 by the Stardust-NExT spacecraft provide an improved shape model and rotational pole for the nucleus (Thomas, P.C. et al. [2012]. Icarus 222, 453-466) that allows us to greatly improve our knowledge of its rotational evolution beyond that outlined earlier in Belton et al. (Belton, M.J.S. e…
Probing the inner boundaries of Saturn's A ring with the Iapetus -1:0 nodal bending wave
Porco, Carolyn C.; Hedman, Matthew M.; Burns, Joseph A. +2 more
The Iapetus -1:0 nodal bending wave, the first spiral wave ever described in Saturn's rings, has been seen again for the first time in 29 years. We demonstrate that it is in fact the nodal bending wave, not the 1:0 apsidal density wave as previously reported. We use wavelet analysis to determine the wavelength profile, thus deriving the surface de…
Valleys in pit craters on Mars: Characteristics, distribution, and formation mechanisms
Fassett, Caleb I.; Peel, Samantha E.
New observations of central pit craters on Mars reveal that some craters contain prominent interior valley networks that drain into their central pit. In this study, we catalog the distribution of pit craters with associated valleys, and characterize in detail five diverse, well-preserved examples. In some instances, sedimentary deposits we interp…
The characteristics of the O2 Herzberg II and Chamberlain bands observed with VIRTIS/Venus Express
Drossart, P.; Piccioni, G.; Soret, L. +6 more
The oxygen Venus nightglow emissions in the visible spectral range have been known since the early observations from the Venera spacecraft. Recent observations with the VIRTIS instrument on board Venus Express allowed us to re-examine the Herzberg II system of O2 and to further study its vertical distribution, in particular the (0-ν″ wi…
HMT production and sublimation during thermal process of cometary organic analogs. Implications for its detection with the ROSETTA instruments
Cottin, Hervé; Fray, Nicolas; Benilan, Yves +3 more
One important component of refractory organic residues synthesized from interstellar/cometary ice analogues is hexamethylenetetramine (HMT, C6H12N4). However, HMT has never been observed in any astrophysical or planetary environment so far. We investigated thermal evolution of HMT above ambient temperature. The syn…
Scattering properties of Saturn's rings in the far ultraviolet from Cassini UVIS spectra
Colwell, Joshua E.; Esposito, Larry W.; Bradley, E. Todd
We use Cassini UVIS data to determine the scattering properties of Saturn's ring particles in the FUV. We have replaced the scattering function from the classical Chandrasekhar single scattering radiative transfer equation for reflectance with a ring wake model for the A and B rings derived from stellar occultations. The free parameters in this mo…