Search Publications
Venus nitric oxide nightglow mapping from SPICAV nadir observations
Bertaux, J. -L.; Gérard, J. -C.; Stiepen, A. +2 more
Nitric oxide δ (190-240 nm) and γ (255-270 nm) bands have been observed on the Venus nightside with Venus Express SPICAV instrument operated in the nadir mode. These ultraviolet emissions arise from the de-excitation of NO molecules created by radiative recombination of O(3P) and N(4S) atoms. These atoms are produced on the d…
Saturn’s ring temperatures at equinox
Spilker, Linda; Ferrari, Cecile; Morishima, Ryuji
Modeling the thermal emission of Saturn’s rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to re…
Hubble observations of Jupiter’s north-south conjugate ultraviolet aurora
Bonfond, B.; Clarke, J. T.; Gérard, J. -C. +2 more
Comparisons of the northern and southern far ultraviolet (UV) auroral emissions of Jupiter from the Hubble Space Telescope (HST) or any other ultraviolet imager have mostly been made so far on a statistical basis or were not obtained with high sensitivity and resolution. Such observations are important to discriminate between different mechanisms …
The smallest particles in Saturn’s A and C Rings
Nicholson, Philip D.; Hedman, Matthew M.; Harbison, Rebecca A.
Radio occultations of Saturn’s main rings by spacecraft suggest a power law particle size-distribution down to sizes of the order of 1 cm (Marouf, E.A., Tyler, G.L., Zebker, H.A., Simpson, R.A., Eshleman, V.R. [1983]. Icarus 54, 189-211; Zebker, H.A., Marouf, E.A., Tyler, G.L. [1985]. Icarus 64, 531-548.). The lack of optical depth variations betw…
The thermo-chemical evolution of Asteroid 21 Lutetia
Neumann, Wladimir; Breuer, Doris; Spohn, Tilman
In the present study, we model the thermo-chemical evolution of Asteroid 21 Lutetia using new data obtained by the Rosetta flyby in July 2010. We investigate the dependence of the evolution on the accretion onset time and duration for both instantaneous accretion and continuous accretion scenarios, assuming late runaway material accumulation. The …
A 3D general circulation model for Pluto and Triton with fixed volatile abundance and simplified surface forcing
Michaels, Timothy I.; Zalucha, Angela M.
We present a 3D general circulation model of Pluto and Triton's atmospheres, which uses radiative-conductive-convective forcing. In both the Pluto and Triton models, an easterly (prograde) jet is present at the equator with a maximum magnitude of 10-12 m s-1 and 4 m s-1, respectively. Neither atmosphere shows any significant …
Oxygen nightglow emissions of Venus: Vertical distribution and collisional quenching
Piccioni, G.; Gérard, J. -C.; Soret, L. +1 more
We compare the altitude of three O2 night airglow emissions observed at the limb of Venus by the VIRTIS spectral imager with those values predicted by a model accounting for the different radiative lifetimes and collisional deactivation of the upper O2 states. The O and CO2 density profiles are based on remote sens…
Dust in Comet 103P/Hartley 2 coma during EPOXI mission
Lasue, J.; Sen, A. K.; Gupta, R. +3 more
The Deep Impact spacecraft flew by Comet 103P/Hartley 2 on 4 November 2010 (EPOXI mission). In situ observations are complemented by a systematic ground- and space-based observation campaign. In the present work, imaging polarimetry is used to emphasize different dust regions in the coma and follow their evolution over a period including the EPOXI…
Knob fields in the Terra Cimmeria/Terra Sirenum region of Mars: Stratigraphy, mineralogy and morphology
Neukum, Gerhard; Bishop, Janice L.; Wendt, Lorenz
We investigate the stratigraphy, morphology and mineralogy of five major knob fields in the region between Terra Cimmeria and Terra Sirenum on Mars based on HRSC, CTX, MOC and HiRISE imagery together with hyperspectral data from CRISM. The knob fields comprise Ariadnes Colles, Atlantis Chaos and Gorgonum Chaos and further, unnamed fields of mounds…
Outflow channels with deltaic deposits in Ismenius Lacus, Mars
Mangold, Nicolas; Howard, Alan D.
A connected series of outflow channels in the Ismenius Lacus quadrangle are identified for the first time and characterized using High Resolution Stereo Camera images of Mars Express, the Context camera images of Mars Reconnaissance Orbiter and the topography of the Mars Observer Laser Altimeter. These channels (named Okavango Valles), which stret…