Search Publications
The structure of Titan’s atmosphere from Cassini radio occultations: Occultations from the Prime and Equinox missions
French, Richard G.; Flasar, F. Michael; Marouf, Essam A. +7 more
We present the results of six soundings of the atmosphere of Titan by the radio occultation technique using the Cassini spacecraft currently in orbit around Saturn. These occultations occurred during four separate targeted Titan encounters in both the Prime and Equinox missions of Cassini over 3 years. They cover a wide range of latitude from 75°S…
Climate-driven deposition of water ice and the formation of mounds in craters in Mars’ north polar region
Le Mouélic, Stéphane; Conway, Susan J.; Orosei, Roberto +4 more
This paper explores the origins and evolution of ice-rich interior mounds found within craters of the north polar region of Mars. We present a systematic study of impact craters above 65°N, and identify 18 craters that have interior mounds. At least 11 of these mounds are composed of water ice and geometric similarities suggest that dune-covered m…
Water vapor near the cloud tops of Venus from Venus Express/VIRTIS dayside data
Drossart, P.; Piccioni, G.; Grassi, D. +3 more
Observations of the dayside of Venus performed by the high spectral resolution channel (-H) of the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board the ESA Venus Express mission have been used to measure the altitude of the cloud tops and the water vapor abundance around this level with a spatial resolution ranging from 100 to 1…
Geomorphological significance of Ontario Lacus on Titan: Integrated interpretation of Cassini VIMS, ISS and RADAR data and comparison with the Etosha Pan (Namibia)
Le Mouélic, S.; Cornet, T.; Rodriguez, S. +11 more
Ontario Lacus is the largest lake of the whole southern hemisphere of Titan, Saturn's major moon. It has been imaged twice by each of the Cassini imaging systems (Imaging Science Subsystem (ISS) in 2004 and 2005, Visual and Infrared Mapping Spectrometer (VIMS) in 2007 and 2009 and RADAR in 2009 and 2010). We compile a geomorphological map and deri…
Patterns of accumulation and flow of ice in the mid-latitudes of Mars during the Amazonian
Head, James W.; Fassett, Caleb I.; Dickson, James L.
Evidence has accumulated that non-polar portions of Mars have undergone significant periods of glaciation during the Amazonian Period. This evidence includes tropical mountain glacial deposits, lobate debris aprons, lineated valley fill, concentric crater fill, pedestal craters, and related landforms, some of which suggest that ice thicknesses exc…
Mars exospheric thermal and non-thermal components: Seasonal and local variations
Leblanc, F.; Modolo, R.; Hess, S. +3 more
A model of the martian exosphere is built for average solar conditions. A Chamberlain’s approach (Chamberlain, J.W. [1963]. Planet. Space Sci. 11, 901) is used to describe the O, CO, CO2, and O2 thermal exospheric components. The average thermal oxygen density at 300 km in altitude varies by about one order of magnitude with …
Physical properties of trans-neptunian binaries (120347) Salacia-Actaea and (42355) Typhon-Echidna
Buie, M. W.; Rieke, G. H.; Roe, H. G. +7 more
We report new Hubble Space Telescope and Spitzer Space Telescope results concerning the physical properties of the trans-neptunian object (TNO) binaries (120347) Salacia-Actaea (formerly 2004 SB60), and (42355) Typhon-Echidna (formerly 2002 CR46). The mass of the (120347) Salacia-Actaea system is 4.66 ± 0.22 × 1020…
Enceladus: A hypothesis for bringing both heat and chemicals to the surface
Matson, Dennis L.; Johnson, Torrence V.; Castillo-Rogez, Julie C. +1 more
The eruptive plumes and large heat flow (∼15 GW) observed by Cassini in the South Polar Region of Enceladus may be expressions of hydrothermal activity inside Enceladus. We hypothesize that a subsurface ocean is the heat reservoir for thermal anomalies on the surface and the source of heat and chemicals necessary for the plumes. The ocean is belie…
Composition and structures of the subsurface in the vicinity of Valles Marineris as revealed by central uplifts of impact craters
Quantin, Cathy; Flahaut, Jessica; Clenet, Harold +2 more
Despite recent efforts from space exploration to sound the martian subsurface with RADAR, the structure of the martian subsurface is still unknown. Major geologic contacts or discontinuities inside the martian crust have not been revealed. Another way to analyze the subsurface is to study rocks that have been exhumed from depth by impact processes…
Radar properties of comets: Parametric dielectric modeling of Comet 67P/Churyumov-Gerasimenko
Kofman, Wlodek; Heggy, Essam; Palmer, Elizabeth M. +3 more
In 2014, the European Space Agency’s Rosetta mission is scheduled to rendezvous with Comet 67P/Churyumov-Gerasimenko (Comet 67P). Rosetta’s CONSERT experiment aims to explore the cometary nucleus’ geophysical properties using radar tomography. The expected scientific return and inversion algorithms are mainly dependent on our understanding of the …