Search Publications
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 …
Constraints on mantle plumes on Venus: Implications for volatile history
Sotin, Christophe; Smrekar, Suzanne E.
The analysis of Venus' gravity field and topography suggests the presence of a small number of deep mantle plumes (∼9). This study predicts the number of plumes formed at the core-mantle boundary, their characteristics, and the production of partial melt from adiabatic decompression. Numerical simulations are performed using a 3D spherical code th…
Magnetosphere-atmosphere coupling at Saturn: 1 - Response of thermosphere and ionosphere to steady state polar forcing
Galand, M.; Moore, L.; Müller-Wodarg, I. C. F. +2 more
We present comprehensive calculations of the steady state response of Saturn’s coupled thermosphere-ionosphere to forcing by solar radiation, magnetospheric energetic electron precipitation and high latitude electric fields caused by sub-corotation of magnetospheric plasma. Significant additions to the physical processes calculated in our Saturn T…
Valleys, paleolakes and possible shorelines at the Libya Montes/Isidis boundary: Implications for the hydrologic evolution of Mars
Poulet, F.; Jaumann, R.; Hiesinger, H. +5 more
We describe the results of our morphologic, stratigraphic and mineralogic investigations of fluvial landforms, paleolakes and possible shoreline morphologies at the Libya Montes/Isidis Planitia boundary. The landforms are indicative of aqueous activity and standing bodies of water, including lakes, seas and oceans, that are attributed to a complex…
Geologic interpretation of the near-infrared images of the surface taken by the Venus Monitoring Camera, Venus Express
Scholten, F.; Roatsch, Th.; Fiethe, B. +9 more
We analyze night-time near-infrared (NIR) thermal emission images of the Venus surface obtained with the 1-µm channel of the Venus Monitoring Camera onboard Venus Express. Comparison with the results of the Magellan radar survey and the model NIR images of the Beta-Phoebe region show that the night-time VMC images provide reliable informatio…
The abundance, vertical distribution and origin of H2O in Titan’s atmosphere: Herschel observations and photochemical modelling
Hartogh, Paul; Lellouch, Emmanuel; Lara, Luisa M. +4 more
Disk-averaged observations of water vapor in Titan’s atmosphere acquired with the Herschel satellite are reported. We use a combination of unresolved measurements of three H2O rotational lines at 66.4, 75.4 and 108.0 µm with the PACS instrument, and spectrally-resolved observations of two other transitions at 557 GHz (538 µm…