Search Publications
Latitude dependence of Martian pedestal craters: Evidence for a sublimation-driven formation mechanism
Head, James W.; Kadish, Seth J.; Barlow, Nadine G.
We report on the results of a survey to document and characterize pedestal craters on Mars equatorward of ∼60°N and 65°S latitude. The identification of 2696 pedestal craters reveals a strong latitude dependence, with the vast majority found poleward of 33°N and 40°S. This latitudinal extent is correlated with many climate indicators consistent wi…
Distribution of hydrated minerals in the north polar region of Mars
Mustard, J. F.; Noe Dobrea, E. Z.; Bell, J. F. +5 more
The previous discovery of extensive deposits of hydrated minerals in Olympia Planum in the north polar region of Mars by the Mars Express OMEGA instrument raises important questions about the origin and subsequent redistribution of these hydrated minerals. Here we present a new map of the distribution of hydrated minerals within the north polar re…
Venus Express mission
Witasse, O.; Svedhem, H.; Titov, D. +1 more
Venus Express is well and healthy and has now been providing exciting new data from Venus, our nearby twin planet, for over 2 years. Many of the new results are presented and discussed in the subsequent papers in this special section. The overall scientific objective of Venus Express is to carry out a detailed study of the atmosphere of Venus, inc…
Martian oxygen density at the exobase deduced from O I 130.4-nm observations by Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars on Mars Express
Leblanc, F.; Bertaux, J. L.; Quémerais, E. +1 more
Several observations of the O I 130.4-nm triplet have been analyzed to determine the oxygen density in the Martian upper atmosphere using a three-dimensional Monte Carlo radiative transfer model describing each line of the triplet. Solar resonant scattering is the dominant source of excitation of the O I 130.4-nm triplet in the upper atmosphere of…
Preliminary characterization of the upper haze by SPICAV/SOIR solar occultation in UV to mid-IR onboard Venus Express
Vandaele, A. C.; Montmessin, F.; Fedorova, A. +6 more
The Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus/Solar Occultation at Infrared (SPICAV/SOIR) suite of instruments onboard the Venus Express spacecraft comprises three spectrometers covering a wavelength range from ultraviolet to midinfrared and an altitude range from 70 to >100 km. However, it is only recently (m…
Near-IR oxygen nightglow observed by VIRTIS in the Venus upper atmosphere
Drossart, P.; Piccioni, G.; García Muñoz, A. +5 more
We present observations of both the (0-0) and (0-1) bands at 1.27 and 1.58 µm of the O2(a1Δg - X3Σg -) nightglow made with the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument aboard Venus Express. The observations were conducted in both nadir and limb vie…
A ground-to-exosphere Martian general circulation model: 2. Atmosphere during solstice conditions—Thermospheric polar warming
Forget, F.; López-Valverde, M. A.; González-Galindo, F. +1 more
A ground-to-exosphere Martian general circulation model is applied to study the thermal and dynamical structure of the upper Martian atmosphere during solstitial conditions. Special attention is paid to the reproduction of the thermospheric polar warming observed by Mars Odyssey during southern hemisphere (SH) summer solstice. The intensity and la…
Venus cloud top winds from tracking UV features in Venus Monitoring Camera images
Jaumann, R.; Hviid, S. F.; Matz, K. -D. +10 more
To date dynamical observations of the Venus clouds have delivered mainly either only short-term or long-term averaged results. With the Venus Monitoring Camera (VMC) it finally became possible to investigate the global dynamics with a relatively high resolution in space and time on a long-term basis. Our findings from manual cloud feature wind tra…
Plasma environment of Venus: Comparison of Venus Express ASPERA-4 measurements with 3-D hybrid simulations
Barabash, S.; Lundin, R.; Krupp, N. +13 more
We use data of the ASPERA-4 ion and electron spectrometers onboard Venus Express to determine the locations and shapes of the plasma boundaries (bow shock, ion composition boundary, and mantle) at Venus. We also investigate the variation of the terminator bow shock position as a function of the solar wind dynamic pressure and solar EUV flux. We co…
Water vapor abundance near the surface of Venus from Venus Express/VIRTIS observations
Drossart, Pierre; Bézard, Bruno; Marcq, Emmanuel +3 more
Nightside observations of the 1.18-µm atmospheric window by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) aboard the Venus Express spacecraft were analyzed to measure and map the water vapor abundance in the lower atmosphere. Thermal emission in this window originates partly from the surface and partly from the first scale h…