Search Publications
Recent orbital evolution and the internal structures of Enceladus and Dione
Zhang, Ke; Nimmo, Francis
We study the orbital behavior of Saturn's satellites Enceladus and Dione during their passage through the 2:1 mean-motion resonances to constrain their interior structures, parameterized by the quantity k2/Q (assumed constant). Enceladus' evolution after escape from the second-order e-Enceladus e-Dione resonance requires that (k2
Rain and dewdrops on titan based on in situ imaging
Karkoschka, Erich; Tomasko, Martin G.
The Descent Imager/Spectral Radiometer (DISR) of the Huygens probe was in an excellent position to view aspects of rain as it descended through Titan's atmosphere. Rain may play an important part of the methane cycle on Titan, similar to the water cycle on Earth, but rain has only been indirectly inferred in previous studies. DISR detected two dar…
Geologic context of in situ rocky exposures in Mare Serpentis, Mars: Implications for crust and regolith evolution in the cratered highlands
Rogers, A. D.; Aharonson, O.; Bandfield, J. L.
Global acquisition of infrared spectra and high-resolution visible and infrared imagery has enabled the placement of compositional information within stratigraphic and geologic context. Mare Serpentis, a low albedo region located northwest of Hellas Basin, is rich in spectral and thermophysical diversity and host to numerous isolated exposures of …
The absence of endogenic methane on Titan and its implications for the origin of atmospheric nitrogen
Desch, Steven J.; Glein, Christopher R.; Shock, Everett L.
We calculate the D/H ratio of CH 4 from serpentinization on Titan to determine whether Titan's atmospheric CH 4 was originally produced inside the giant satellite. This is done by performing equilibrium isotopic fractionation calculations in the CH 4-H 2O-H 2 system, with the assumption that t…
MARSIS surface reflectivity of the south residual cap of Mars
Plaut, J. J.; Safaeinili, A.; Mouginot, J. +3 more
The south residual cap of Mars is commonly described as a thin and bright layer of CO 2-ice. The Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) is a low-frequency radar on board Mars Express operating at the wavelength between 55 and 230 m in vacuum. The reflection of the radar wave on a stratified medium like the …
Titania's radius and an upper limit on its atmosphere from the September 8, 2001 stellar occultation
Sutherland, W.; Colas, F.; Lellouch, E. +150 more
On September 8, 2001 around 2 h UT, the largest uranian moon, Titania, occulted Hipparcos star 106829 (alias SAO 164538, a V=7.2, K0 III star). This was the first-ever observed occultation by this satellite, a rare event as Titania subtends only 0.11 arcsec on the sky. The star's unusual brightness allowed many observers, both amateurs or professi…
Atomic oxygen distribution in the Venus mesosphere from observations of O 2 infrared airglow by VIRTIS-Venus Express
Drossart, Pierre; Bertaux, Jean-Loup; Piccioni, Giuseppe +3 more
This VIRTIS instrument on board Venus Express has collected spectrally resolved images of the Venus nightside limb that show the presence of the (0,0) band of the Δg1→Σg3 infrared atmospheric system of O 2 at 1.27 µm. The emission is produced by three-body recombination of oxygen atoms created by photodissociation of CO 2
Variability of CO concentrations in the Venus troposphere from Venus Express/VIRTIS using a Band Ratio Technique
Irwin, P. G. J.; Drossart, P.; Piccioni, G. +5 more
A fast method is presented for deriving the tropospheric CO concentrations in the Venus atmosphere from near-infrared spectra using the night side 2.3 µm window. This is validated using the spectral fitting techniques of Tsang et al. [Tsang, C.C.C., Irwin, P.G.J., Taylor, F.W., Wilson, C.F., Drossart, P., Piccioni, G., de Kok, R., Lee, C., C…
The jovian anticyclone BA. III. Aerosol properties and color change
Hueso, R.; Sánchez-Lavega, A.; García-Melendo, E. +2 more
A study of the vertical cloud structure of oval BA and its red color change is presented in this third part of our complete analysis. A large interest in Jupiter's anticyclone BA was created by its reddening that occurred between 2005 and 2006. In this work we quantify the color change in oval BA by using images taken with the Advanced Camera for …
Saturn's latitudinal C 2H 2 and C 2H 6 abundance profiles from Cassini/CIRS and ground-based observations
Fletcher, Leigh N.; Nixon, Conor A.; Achterberg, Richard K. +8 more
Hydrocarbons in the upper atmosphere of Saturn are known, from Voyager, ground-based, and early Cassini results, to vary in emission intensity with latitude. Of particular interest is the marked increase in hydrocarbon line intensity near the south pole during southern summer, as the increased line intensity cannot be simply explained by the incre…