Search Publications
Cold ion escape from the Martian ionosphere
Fedorov, A.; Barabash, S.; Fränz, M. +3 more
We here report on new measurements of the escape flux of oxygen ions from Mars by combining the observations of the ASPERA-3 and MARSIS experiments on board the European Mars Express spacecraft. We show that in previous estimates of the total heavy ion escape flow the contribution of the cold ionospheric outflow with energies below 10 eV has been …
The CO2 continuum absorption in the 1.10- and 1.18-µm windows on Venus from Maxwell Montes transits by SPICAV IR onboard Venus express
Bertaux, Jean-Loup; Korablev, Oleg; Bézard, Bruno +2 more
One of the difficulties in modeling Venus' nightside atmospheric windows is the need to apply CO2 continuum opacity due to collision-induced CO2 bands and/or extreme far wings of strong allowed CO2 bands. Characterizing the CO2 continuum absorption at near-IR wavelengths as well as searching for a possib…
Plasma regions, charged dust and field-aligned currents near Enceladus
Gurnett, D. A.; Dougherty, M. K.; Kurth, W. S. +7 more
We use data from several instruments on board Cassini to determine the characteristics of the plasma and dust regions around Saturn's moon Enceladus. For this we utilize the Langmuir probe and the electric antenna connected to the wideband receiver of the radio and plasma wave science (RPWS) instrument package as well as the magnetometer (MAG). We…
Craters on comets
Vincent, Jean-Baptiste; Oklay, Nilda; Sierks, Holger +2 more
This paper reviews the observations of crater-like features on cometary nuclei. We compare potential crater sizes and morphologies, and we discuss the probability of impacts between small asteroids in the Main Belt and a comet crossing this region of the Solar System. Finally, we investigate the fate of the impactor and its chances of survival on …
Lower atmosphere minor gas abundances as retrieved from Venus Express VIRTIS-M-IR data at 2.3 µm
Haus, Rainer; Kappel, David; Arnold, Gabriele
Minor gas abundances in the lower atmosphere of Venus' southern hemisphere are investigated using spectroscopic nightside measurements recorded by the Visible and InfraRed Thermal Imaging Spectrometer aboard ESA's Venus Express mission in the moderate spectral resolution infrared mapping channel (VIRTIS-M-IR, 1-5 µm, FWHM=17 nm). The entire …
Carbon monoxide short term variability observed on Venus with SOIR/VEX
Vandaele, A. C.; Robert, S.; Wilquet, V. +3 more
The SOIR instrument on board the ESA Venus Express mission has been operational since the insertion of the satellite around Venus in 2006. Since then, it has delivered high quality spectra of the atmosphere of Venus. Spectra are recorded in the IR spectral region (2.2-4.3 µm) using the solar occultation geometry and give access to a vast num…
Rotational temperatures of Venus upper atmosphere as measured by SOIR on board Venus Express
Vandaele, A. C.; Robert, S.; Wilquet, V. +6 more
SOIR is a powerful infrared spectrometer flying on board the Venus Express spacecraft since mid-2006. It sounds the Venus atmosphere above the cloud layer using the solar occultation technique. In the recorded spectra, absorption structures from many species are observed, among them carbon dioxide, the main constituent of the Venus atmosphere. Pre…
Groove formation on Phobos: Testing the Stickney ejecta emplacement model for a subset of the groove population
Head, James W.; Wilson, Lionel
Numerous theories have been proposed for the formation of grooves on Phobos, and no single explanation is likely to account fully for the wide variety of observed groove morphologies and orientations. One set of grooves is geographically associated with the impact crater Stickney. We test the hypothesis that these grooves were formed by clasts tha…
Estimating precipitation on early Mars using a radiative-convective model of the atmosphere and comparison with inferred runoff from geomorphology
Rauer, H.; Jaumann, R.; Tirsch, D. +5 more
We compare estimates of atmospheric precipitation during the Martian Noachian-Hesperian boundary 3.8 Gyr ago as calculated in a radiative-convective column model of the atmosphere with runoff values estimated from a geomorphological analysis of dendritic valley network discharge rates. In the atmospheric model, we assume CO2-H2
The radiative forcing variability caused by the changes of the upper cloud vertical structure in the Venus mesosphere
Pätzold, M.; Piccioni, G.; Ignatiev, N. I. +3 more
The upper cloud layer of Venus is a key factor affecting radiative energy balance of the mesosphere. Observations of the temperature and the cloud top structure by Venus Express revealed their strong variability with latitude. We used the 1-D radiative transfer model to study the dependence of the radiative forcing on the cloud top structure. The …