Search Publications
Meridional distribution of CH3C2H and C4H2 in Saturn’s stratosphere from CIRS/Cassini limb and nadir observations
Fletcher, Leigh N.; Bézard, Bruno; Guerlet, Sandrine +4 more
Limb and nadir spectra acquired by Cassini/CIRS (Composite InfraRed Spectrometer) are analyzed in order to derive, for the first time, the meridional variations of diacetylene (C 4H 2) and methylacetylene (CH 3C 2H) mixing ratios in Saturn's stratosphere, from 5 hPa up to 0.05 hPa and 80°S to 45°N. We fi…
The photochemical products of benzene in Titan’s upper atmosphere
Delitsky, M. L.; McKay, C. P.
The Cassini spacecraft detected benzene high in Titan's atmosphere as well as the presence of large mass positive and negative ions. Previous work has suggested that these large mass ions could be composed of fused-ring polycyclic aromatic hydrocarbon compounds. These fused-ring PAHs, such as naphthalene and anthracene, are usually the result of h…
Convective cloud heights as a diagnostic for methane environment on Titan
Barth, Erika L.; Rafkin, Scot C. R.
The appearance of convective clouds in Titan's troposphere has been documented from ground-based observation for more than a decade. Cloud tops have been reported between 14 and 25 km. Higher resolution Cassini data have shown smaller portions of the cloud system can reach up to 42 km. We use the Titan Regional Atmospheric Modeling System (TRAMS) …
A multi-wavelength study of the 2009 impact on Jupiter: Comparison of high resolution images from Gemini, Keck and HST
de Pater, Imke; Wong, Michael H.; Fletcher, Leigh N. +6 more
Within several days of A. Wesley's announcement that Jupiter was hit by an object on UT 19 July 2009, we observed the impact site with (1) the Hubble Space Telescope (HST) at UV through visible (225-924 nm) wavelengths, (2) the 10-m W.M. Keck II telescope in the near-infrared (1-5 µm), and (3) the 8-m Gemini-North telescope in the mid-infrar…
The source of 3-µm absorption in Jupiter’s clouds: Reanalysis of ISO observations using new NH3 absorption models
Sromovsky, L. A.; Fry, P. M.
A prominent characteristic of jovian near-IR spectra is the widely distributed presence of a strong absorption at wavelengths from about 2.9 µm to 3.1 µm, first noticed in a 3-µm spectrum obtained by the Infrared Space Observatory (ISO) in 1996. While Brooke et al. (Brooke, T.Y., Knacke, R.F., Encrenaz, T., Drossart, P., Crisp, D…
Temporary liquid water in upper snow/ice sub-surfaces on Mars?
Möhlmann, Diedrich T. F.
It is investigated whether conditions for melting can be temporarily created in the upper sub-surface parts of snow/ice-packs on Mars at subzero surface temperatures by means of the solid-state greenhouse effect, as occurs in snow- and ice-covered regions on Earth. The conditions for this possible temporary melting are quantitatively described for…
Investigating gully flow emplacement mechanisms using apex slopes
McEwen, Alfred S.; Pelletier, Jon D.; Kolb, Kelly Jean
The origin of the martian gullies has been much debated since their discovery by the Mars Orbiter Camera (MOC, Malin, M.C., Edgett, K.S. [2000]. Science 288, 2330-2335). Several previous studies have looked at slope gradients in and around gullies, but none have used Digital Elevation Models (DEMs) from the High Resolution Imaging Science Experime…
Shape and obliquity effects on the thermal evolution of the Rosetta target 67P/Churyumov-Gerasimenko cometary nucleus
Lasue, J.; Coradini, A.; De Sanctis, M. C. +3 more
This work is dedicated to the application to 67P/Churyumov-Gerasimenko of a new quasi-3D approach for non-spherically shaped comet nuclei with the aim to interpret the current activity of the comet in terms of initial characteristics and to predict shape and internal stratification evolution of the nucleus. The model is applied to differently shap…
Self-gravity wake parameters in Saturn’s A and B rings
Nicholson, P. D.; Hedman, M. M.
An increasing body of evidence shows that, at the sub-km level, Saturn's main A and B rings are dominated by an ever-changing pattern of elongated, canted structures known as self-gravity wakes. Best known for causing azimuthal variations in the rings' reflectivity, these structures also have a profound influence on how the transmission of the rin…
On the long-term variability of Jupiter’s winds and brightness as observed from Hubble
Simon-Miller, Amy A.; Gierasch, Peter J.
Hubble Space Telescope Wide Field Planetary Camera 2 imaging data of Jupiter were combined with wind profiles from Voyager and Cassini data to study long-term variability in Jupiter's winds and cloud brightness. Searches for evidence of wind velocity periodicity yielded a few latitudes with potential variability; the most significant periods were …