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Induced magnetosphere and its outer boundary at Venus
Barabash, S.; Russell, C. T.; Wei, H. Y. +8 more
The induced magnetosphere at Venus consists of regions near the planet and its wake for which the magnetic pressure dominates all other pressure contributions. Initial Venus Express measurements indicate a well-defined outer boundary, the magnetopause, of the induced magnetosphere. This magnetopause acts as an obstacle to deflect the solar wind. A…
Mirror-mode-like structures in Venus' induced magnetosphere
Zhang, T. L.; Glassmeier, K. -H.; Baumjohann, W. +3 more
The solar wind interaction with Venus creates an induced magnetosphere around the planet. It is shown that within the space bound by Venus' bow shock and ionopause, there is a rich occurrence of mirror-mode-like structures in the magnetic field data. The dayside magnetosheath and nightside magnetosheath/wake regions are investigated separately. It…
Morphology and dynamics of Venus oxygen airglow from Venus Express/Visible and Infrared Thermal Imaging Spectrometer observations
Hueso, R.; Sánchez-Lavega, A.; Drossart, P. +5 more
Images obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS)-M channel instrument onboard Venus Express have been used to retrieve maps and apparent motions of the O2 (1Δ) infrared nightglow on Venus at 1.27 µm. The nightglow distribution is highly inhomogeneous with the regions of brightest emissio…
Venus Express observations of atmospheric oxygen escape during the passage of several coronal mass ejections
Fedorov, A.; Barabash, S.; Futaana, Y. +7 more
The solar wind interaction contributes to the loss of Venus atmospheric constituents, especially oxygen, by direct antisunward acceleration of planetary ions and possibly by related sputtering of neutrals. Both comet-like ``ion pickup'' and related sputtering processes may have played a key role in Venus' atmosphere evolution, but the significance…
Tyrrhena Patera: Geologic history derived from Mars Express High Resolution Stereo Camera
Greeley, Ronald; Williams, David A.; Neukum, Gerhard +4 more
We used Mars Express High Resolution Stereo Camera images of the Tyrrhena Patera volcano to assign cratering model ages to material units defined in the Viking Orbiter-based geologic mapping. Cratering model ages are generally consistent with their stratigraphy. We can identify three key intervals of major activity at Tyrrhena Patera: (1) formatio…
Ferric oxides in East Candor Chasma, Valles Marineris (Mars) inferred from analysis of OMEGA/Mars Express data: Identification and geological interpretation
Sotin, Christophe; Le Mouélic, Stéphane; Gendrin, Aline +7 more
The mineralogical composition of the Martian surface is constrained by analyzing the data of the OMEGA visible and near infrared imaging spectrometer onboard Mars Express. Ferric signatures had previously been reported in Valles Marineris, Margaritifer Terra, and Terra Meridiani. Here we use three independent data reduction methods (Spectral Angle…
Topography of valley networks on Mars from Mars Express High Resolution Stereo Camera digital elevation models
Mangold, Nicolas; Neukum, Gerhard; Masson, Philippe +2 more
Martian valley networks have been identified mainly in the Noachian heavily cratered uplands. The geometry of valley networks can be studied using Mars Orbiter Laser Altimeter (MOLA) altimetry, which is sufficient to map large valleys without a detailed 3-D shape of valley networks. Imaging from the Mars Express High Resolution Stereo Camera (HRSC…
Distribution of the ultraviolet nitric oxide Martian night airglow: Observations from Mars Express and comparisons with a one-dimensional model
Reberac, A.; Bertaux, J. -L.; Leblanc, F. +4 more
Limb observations with the SPICAM ultraviolet spectrometer on board the Mars Express orbiter revealed ultraviolet nightglow emission in the δ (190-240 nm) and γ (225-270 nm) bands of nitric oxide. This emission arises from radiative recombination between O(3P) and N(4S) atoms that are produced on the day side and form excited…
A swarm of small shield volcanoes on Syria Planum, Mars
Williams, David A.; Mangold, Nicolas; Bleacher, Jacob E. +7 more
This study focuses on the volcanism in Syria Planum, located at the center of the Tharsis bulge at an altitude of 6 to 8 km above Mars datum. Syria Planum was previously recognized as a center for the tectonic activity of Tharsis, but not as a major locus for volcanic activity, despite its centrality over the bulge. Using high-resolution images fr…
First observations of SO2 above Venus' clouds by means of Solar Occultation in the Infrared
Montmessin, F.; Fedorova, A.; Korablev, O. +6 more
Solar Occultation in the Infrared (SOIR) is a part of the Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus (SPICAV)/SOIR occultation experiment on board Venus Express dedicated to the study of gaseous and aerosol vertical structure of Venus' mesosphere. SOIR is an echelle spectrometer with acoustooptic selection of diff…