Search Publications
A unique volcanic field in Tharsis, Mars: Pyroclastic cones as evidence for explosive eruptions
Hauber, E.; Brož, P.
Based on theoretical grounds, explosive basaltic volcanism should be common on Mars, yet the available morphological evidence is sparse. We test this hypothesis by investigating a unique unnamed volcanic field north of the shield volcanoes Biblis Patera and Ulysses Patera on Mars, where we observe several small conical edifices and associated lava…
Models of the global cloud structure on Venus derived from Venus Express observations
Irwin, P. G. J.; Drossart, P.; Piccioni, G. +6 more
Spatially-resolved near-infrared spectra from the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on Venus Express have been used to derive improved models of the vertical structure and global distribution of cloud properties in the southern hemisphere of Venus. VIRTIS achieved the first systematic, global mapping of Venus at wavelength…
Analytic theory of Titan's Schumann resonance: Constraints on ionospheric conductivity and buried water ocean
Sotin, Christophe; Karkoschka, Erich; Berthelier, Jean-Jacques +6 more
This study presents an approximate model for the atypical Schumann resonance in Titan's atmosphere that accounts for the observations of electromagnetic waves and the measurements of atmospheric conductivity performed with the Huygens Atmospheric Structure and Permittivity, Wave and Altimetry (HASI-PWA) instrumentation during the descent of the Hu…
Optical constants of Titan tholins at mid-infrared wavelengths (2.5-25 µm) and the possible chemical nature of Titan’s haze particles
Khare, Bishun N.; McKay, Christopher P.; Cruikshank, Dale P. +1 more
Complex organic materials may exist as haze layers in the atmosphere of Titan and as dark coloring agents on icy satellite surfaces. Laboratory measurements of optical constants of plausible complex organic materials are necessary for quantitative evaluation from remote sensing observations, and to document the existence of complex organic materia…
The calculation of Afρ and mass loss rate for comets
Rubin, Martin; Fink, Uwe
Ab initio calculations of Afρ are presented using Mie scattering theory and a Direct Simulation Monte Carlo (DSMC) dust outflow model in support of the Rosetta mission and its target 67P/Churyumov-Gerasimenko (CG). These calculations are performed for particle sizes ranging from 0.010 µm to 1.0 cm. The present status of our knowledge of vari…
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…