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Sinuous gullies on Mars: Frequency, distribution, and implications for flow properties
Mangold, N.; Ansan, V.; Mangeney, A. +4 more
Recent gullies on Mars are suspected to be the result of liquid-water-bearing flows. A formation from wet flows has been challenged by studies invoking granular (dry) flows. Our study focuses on the sinuous shapes observed for some of the recent Martian gullies. Sinuous gullies are found in locations and slopes (of 10°-15°) similar to straight gul…
Stratigraphy of hydrated sulfates in the sedimentary deposits of Aram Chaos, Mars
Murchie, Scott L.; Mustard, John F.; Arvidson, Raymond E. +8 more
Sedimentary deposits within the 280 km wide crater containing Aram Chaos (∼3°N, 339°E) have been differentially eroded by wind to expose a stratigraphic column 900-1000 m thick that unconformably overlies the chaos bedrock. A detailed stratigraphic and mineralogical description of the deposits is presented based on data from the Mars Reconnaissanc…
Bathymetry and absorptivity of Titan's Ontario Lacus
Callahan, P.; Hayes, A. G.; Kirk, R. L. +9 more
Ontario Lacus is the largest and best characterized lake in Titan's south polar region. In June and July 2009, the Cassini RADAR acquired its first Synthetic Aperture Radar (SAR) images of the area. Together with closest approach altimetry acquired in December 2008, these observations provide a unique opportunity to study the lake's nearshore bath…
Late Noachian to Hesperian climate change on Mars: Evidence of episodic warming from transient crater lakes near Ares Vallis
Muller, Jan-Peter; Gupta, Sanjeev; Kim, Jung-Rack +3 more
The Ares Vallis region is surrounded by highland terrain containing both degraded and pristine large impact craters that suggest a change in climate during the Late Noachian-Early Hesperian, from warmer, wetter conditions to colder, dryer conditions. However, the regional occurrence of Hesperian-age crater outlet channels indicates that this perio…
Coupling mantle convection and tidal dissipation: Applications to Enceladus and Earth-like planets
Čadek, Ondřej; Tobie, Gabriel; Běhounková, Marie +1 more
Anelastic dissipation of tidal forces likely contributes to the thermal budget of several satellites of giant planets and Earth-like planets closely orbiting other stars. In order to address how tidal heating influences the thermal evolution of such bodies, we describe here a new numerical tool that solves simultaneously mantle convection and tida…
Saturn's emitted power
Fletcher, Leigh N.; West, Robert A.; Porco, Carolyn C. +18 more
Long-term (2004-2009) on-orbit observations by Cassini Composite Infrared Spectrometer are analyzed to precisely measure Saturn's emitted power and its meridional distribution. Our evaluations suggest that the average global emitted power is 4.952 ± 0.035 W m-2 during the period of 2004-2009. The corresponding effective temperature is 9…
A general circulation model ensemble study of the atmospheric circulation of Venus
Lee, C.; Richardson, M. I.
The response of three numerical model dynamical cores to Venus-like forcing and friction is described in this paper. Each dynamical core simulates a super-rotating atmospheric circulation with equatorial winds of 35 ± 10 m/s, maintained by horizontally propagating eddies leaving the equatorial region and inducing a momentum convergence there. We d…
Thermal structure of Venusian nighttime mesosphere as observed by VIRTIS-Venus Express
Drossart, P.; Piccioni, G.; Lebonnois, S. +5 more
The mapping IR channel of the Visual and Infrared Thermal Imaging Spectrometer (VIRTIS-M) on board the Venus Express spacecraft observes the CO2 band at 4.3 µm at a spectral resolution adequate to retrieve the atmospheric temperature profiles in the 65-96 km altitude range. Observations acquired in the period June 2006 to July 200…
Densities and temperatures in the Venus mesosphere and lower thermosphere retrieved from SOIR on board Venus Express: Retrieval technique
Vandaele, A. C.; Robert, S.; Wilquet, V. +5 more
The SOIR instrument, flying on board Venus Express, operates in the infrared spectral domain and uses the solar occultation technique to determine the vertical profiles of several key constituents of the Venus atmosphere. The retrieval algorithm is based on the optimal estimation method, and solves the problem simultaneously on all spectra belongi…
A sensitivity study of the Enceladus torus
Delamere, P. A.; Bagenal, F.; Fleshman, B. L.
We have developed a homogeneous model of physical chemistry to investigate the neutral-dominated, water-based Enceladus torus. Electrons are treated as the summation of two isotropic Maxwellian distributions: a thermal component and a hot component. The effects of electron impact, electron recombination, charge exchange, and photochemistry are inc…