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The dispersal of pyroclasts from ancient explosive volcanoes on Mars: Implications for the friable layered deposits

Head, James W.; Forget, François; Madeleine, Jean-Baptiste +2 more

A number of voluminous, fine-grained, friable deposits have been mapped on Mars. The modes of origin for these deposits are debated. The feasibility for an origin by volcanic airfall for the friable deposits is tested using a global circulation model to simulate the dispersal of pyroclasts from candidate source volcanoes near each deposit. It is c…

Comparison of line-by-line and band models of near-IR methane absorption applied to outer planet atmospheres

Sromovsky, L. A.; Fry, P. M.; Boudon, V. +2 more

Recent improvements in high spectral resolution measurements of methane absorption at wavenumbers between 4800 cm^-1 and 7919 cm^-1 have greatly increased the number of lines with known lower state energies, the number of weak lines, and the number of lines observed at low temperatures (Campargue, A., Wang, L., Kassi, S., Mašát…

Assessing the long-term variability of Venus winds at cloud level from VIRTIS-Venus Express

Hueso, R.; Sánchez-Lavega, A.; Peralta, J.

The Venus Express (VEX) mission has been in orbit to Venus for more than 4 years now. The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument onboard VEX observes Venus in two channels (visible and infrared) obtaining spectra and multi-wavelength images of the planet that can be used to sample the atmosphere at different altitude…

Optical constants of Titan's stratospheric aerosols in the 70-1500 cm^-1 spectral range constrained by Cassini/CIRS observations

Bézard, Bruno; Vinatier, Sandrine; de Kok, Remco +3 more

We utilized aerosol extinction coefficient inferred from Cassini/CIRS spectra in the far and mid infrared region to derive the extinction cross-section near an altitude of 190 km at 15°S (from far-IR) and 20°S (from mid-IR). By comparing the extinction cross section that are derived from observations with theoretical calculations for a fractal agg…

Dynamical properties of the Venus mesosphere from the radio-occultation experiment VeRa onboard Venus Express

Pätzold, M.; Häusler, B.; Tellmann, S. +4 more

The dynamics of Venus' mesosphere (60-100 km altitude) was investigated using data acquired by the radio-occultation experiment VeRa on board Venus Express. VeRa provides vertical profiles of density, temperature and pressure between 40 and 90 km of altitude with a vertical resolution of few hundred meters of both the Northern and Southern hemisph…

Tidally-induced melting events as the origin of south-pole activity on Enceladus

Čadek, Ondřej; Tobie, Gabriel; Běhounková, Marie +1 more

The intense activity at the south pole of Enceladus hints at an internal water reservoir. However, there is no direct evidence of liquid water at present and its long-term stability in the interior remains problematic. By modeling heat production and transfer in the ice shell in a spherical geometry, we show that tidal heating naturally leads to a…

The origin and evolution of Saturn’s 2011-2012 stratospheric vortex

Fletcher, Leigh N.; Sánchez-Lavega, A.; García-Melendo, E. +12 more

The planet-encircling springtime storm in Saturn’s troposphere (December 2010-July 2011, Fletcher, L.N. et al. [2011]. Science 332, 1413-1414; Sánchez-Lavega, A. et al. [2011]. Nature 475, 71-74; Fischer, G. et al. [2011]. Nature 475, 75-77) produced dramatic perturbations to stratospheric temperatures, winds and composition at mbar pressures that…

Mid- and far-infrared absorption spectroscopy of Titan’s aerosols analogues

Vinatier, Sandrine; Mahjoub, Ahmed; Anderson, Carrie M. +7 more

In this work we present mid- and far-infrared absorption spectra of Titan’s aerosol analogues produced in the PAMPRE experimental setup. The evolution of the linear absorption coefficient ɛ (cm^-1) is given as a function of the wavenumber.

We provide a complete dataset regarding the influence that the concentration of methane vapor …

Small-scale temperature fluctuations seen by the VeRa Radio Science Experiment on Venus Express

Pätzold, M.; Hinson, D. P.; Bird, M. K. +6 more

The Venus Express Radio Science Experiment VeRa retrieves atmospheric profiles in the mesosphere and troposphere of Venus in the approximate altitude range of 40-90 km. A data set of more than 500 profiles was retrieved between the orbit insertion of Venus Express in 2006 and the end of occultation season No. 11 in July 2011. The atmospheric profi…

Orbital identification of clays and carbonates in Gusev crater

Poulet, Francois; Carter, John

Gusev crater was selected as the landing site of one of the two NASA Mars Exploration Rovers because water once could have ponded within the crater and partly filled it with sediments as suggested by the presence of a feeder channel and the fluvial-lacustrine morphology of the in-filling. However, the paucity of mineralogical evidence for fluvial-…