Search Publications
Structure of the Venus atmosphere
Khatuntsev, I.; Zasova, L. V.; Ignatiev, N. +1 more
The structure of the Venus atmosphere is discussed. The data obtained in the 1980s by the last Soviet missions to Venus: orbiters Venera 15, 16 and the entry probes and balloons of Vega 1 and 2 are compared with the Venus International Reference Atmosphere (VIRA) model. VIRA is based on the data of the extensive space investigations of Venus in th…
Mineralogy and evolution of the surface of Mars: A review
Chevrier, V.; Mathé, P. E.
We review the mineralogy of the surface of Mars, using data from various sources, including in situ characterisations performed by landers, remote observations from orbit, and studies of the SNC meteorites. We also discuss the possible alteration processes and the factor controlling them, and try to relate the mineralogical observations to the che…
X-rays from solar system objects
Snowden, Steven L.; Bhardwaj, Anil; Branduardi-Raymont, Graziella +11 more
During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites …
Topography and geomorphology of the Huygens landing site on Titan
Karkoschka, Erich; Tomasko, Martin G.; Kirk, Randolph L. +16 more
The Descent Imager/Spectral Radiometer (DISR) aboard the Huygens Probe took several hundred visible-light images with its three cameras on approach to the surface of Titan. Several sets of stereo image pairs were collected during the descent. The digital terrain models constructed from those images show rugged topography, in places approaching the…
Venus Monitoring Camera for Venus Express
Dierker, C.; Jaumann, R.; Keller, H. U. +28 more
The Venus Express mission will focus on a global investigation of the Venus atmosphere and plasma environment, while additionally measuring some surface properties from orbit. The instruments PFS and SPICAV inherited from the Mars Express mission and VIRTIS from Rosetta form a powerful spectrometric and spectro-imaging payload suite. Venus Monitor…
A review of selected issues concerning the chemistry in Venus’ middle atmosphere
Allen, Mark; Mills, Franklin P.
Even after decades of study using advanced observing instruments and sophisticated numerical models, a number of significant questions remain unanswered concerning the composition and chemistry of Venus' atmosphere. The primary chemical cycles and the interactions among sulfur and chlorine radicals in Venus' middle atmosphere are reviewed to asses…
DISR imaging and the geometry of the descent of the Huygens probe within Titan's atmosphere
Karkoschka, Erich; Schröder, Stefan E.; Tomasko, Martin G. +4 more
The Descent Imager/Spectral Radiometer (DISR) provided 376 images during the descent to Titan and 224 images after landing. Images of the surface had scales between 150 m/pixel and 0.4 mm/pixel, all of which we assembled into a mosaic. The analysis of the surface and haze features in these images and of other data gave tight constraints on the geo…
Photochemical kinetics uncertainties in modeling Titan's atmosphere: First consequences
Dobrijevic, M.; Raulin, F.; Hébrard, E. +1 more
Uncertainties carried by the different kinetic parameters included in photochemical models of planetary atmospheres have rarely been considered even if they are supposed to be contributing mostly to the inconsistencies between observations and computed predictions. In this paper, we report the first detailed analysis of the propagation of uncertai…
Evaluating planetary digital terrain models—The HRSC DTM test
Oberst, J.; Scholten, F.; Neukum, G. +20 more
The High Resolution Stereo Camera (HRSC) has been orbiting the planet Mars since January 2004 onboard the European Space Agency (ESA) Mars Express mission and delivers imagery which is being used for topographic mapping of the planet. The HRSC team has conducted a systematic inter-comparison of different alternatives for the production of high res…
Local plasma processes and enhanced electron densities in the lower ionosphere in magnetic cusp regions on Mars
Gurnett, D. A.; Lundin, R.; Winningham, J. D. +11 more
Both the MARSIS ionospheric sounder and the charged particle instrument package ASPERA-3 are experiments on board the Mars Express spacecraft. Joint observations have shown that events of intense ionospheric electron density enhancements occur in the lower ionosphere of magnetic cusp regions, and that these enhancements are not associated with pre…