Search Publications
Enhanced transport in the polar mesosphere of Jupiter: Evidence from Cassini UVIS helium 584 Å airglow
Parkinson, C. D.; Stewart, A. I. F.; Wong, A. S. +2 more
The eddy diffusion profile (K) in the auroral regions of Jupiter is not well determined. However, because of the intense auroral energy input, eddy mixing is expected to be much more effective and may be responsible for the enhancement of heavy hydrocarbon production in the polar region. In this paper, we estimate the increased eddy mixing in the …
Internal structure of Rhea
Castillo-Rogez, Julie
We model the interior of Rhea on the basis of observational constraints and the results from geodynamical models available in the literature. Ten main types of models are defined, depending on the presence or absence of a high-pressure ice layer (ice II), and the extent of separation of the rock component from the volatiles. The degree-two gravity…
Stratospheric global winds on Titan at the time of Huygens descent
Sonnabend, G.; Kostiuk, T.; Witasse, O. +9 more
Measurements of stratospheric zonal winds on Titan were made in preparation for and during the time of the descent of the Huygens Probe into Titan's atmosphere on 14 January 2005. Fully resolved emission lines from ethane near 11.7 µm were measured on the east, center, and west positions on Titan using the NASA/GSFC Heterodyne Instrument for…
Models of synthetic aperture radar backscattering for bright flows and dark spots on Titan
Paillou, Philippe; Crapeau, Marc; Elachi, Charles +2 more
The synthetic aperture radar (SAR) imaging mode of the Cassini RADAR instrument enables us to map the surface of Titan through its thick atmosphere. The first Cassini close flyby, acquired on 26 October 2004, revealed a complex surface, with areas of low relief and dome-like volcanic constructs, flows, and sinuous channels. In particular, fan-like…
Titan's bright spots: Multiband spectroscopic measurement of surface diversity and hazes
Genzel, R.; Eisenhauer, F.; de Pater, I. +3 more
Spatially resolved near-infrared spectra of Titan, which simultaneously cover two CH4 absorption bands (from 1.45 to 2.45 µm), have been obtained using the SINFONI integral-field spectrometer with adaptive optics at the Very Large Telescope (VLT) of the European Southern Observatory. We observe the enhancement in 2 µm surfac…
Nonequilibrium radiative heat flux modeling for the Huygens entry probe
Magin, T. E.; Caillault, L.; Bourdon, A. +1 more
An electronic collisional-radiative model is proposed to predict the nonequilibrium populations and the radiation of the excited electronic states CN(A, B) and N2(A, B, C) during the entry of the Huygens probe into the atmosphere of Titan. The model is loosely coupled with flow solvers using a Lagrangian method. First, the model was tes…
Titan imagery with Keck adaptive optics during and after probe entry
de Pater, Imke; Brown, Michael E.; Marchis, Franck +6 more
We present adaptive optics data from the Keck telescope, taken while the Huygens probe descended through Titan's atmosphere and on the days following touchdown. No probe entry signal was detected. Our observations span a solar phase angle range from 0.05° up to 0.8°, with the Sun in the west. Contrary to expectations, the east side of Titan's stra…
Bistatic observations of Titan's surface with the Huygens probe radio signal
Lorenz, R. D.; Lebreton, J. -P.; Floury, N. +2 more
Huygens provided an unanticipated bistatic radio scattering experiment from Titan's surface. After a successful entry and descent on Titan, on 14 January 2005, the probe remarkably survived the landing and continued radioing from the surface to the overflying Cassini, until the orbiter set below Titan's local horizon. Here we report high-quality m…
Limits to the abundance of surface CO2 ice on Titan
Coustenis, A.; Dumas, C.; Hartung, M. +1 more
In the context of the Cassini/Huygens mission, we performed supporting ground-based observations to complement the results from the NASA/ESA/ASI space mission to the Saturnian system with particular focus on Titan. On the nights of 18 and 19 December 2004, we conducted adaptive optics observations with VLT/NACO to search for and map the distributi…
Radiative heating predictions for Huygens entry
Magin, T. E.; Caillault, L.; Bourdon, A. +2 more
Radiative heat flux predictions for the Huygens probe entry into Titan's atmosphere are presented in this paper. Radiative heating was computed with the radiation code SPECAIR, assuming a Boltzmann distribution of the excited electronic levels at a characteristic temperature taken as the vibrational temperature of the gas. CN violet is found to be…