Search Publications
Detection of Methane in the Atmosphere of Mars
Encrenaz, Thérèse; Formisano, Vittorio; Giuranna, Marco +2 more
We report a detection of methane in the martian atmosphere by the Planetary Fourier Spectrometer onboard the Mars Express spacecraft. The global average methane mixing ratio is found to be 10 +/- 5 parts per billion by volume (ppbv). However, the mixing ratio varies between 0 and 30 ppbv over the planet. The source of methane could be either bioge…
Recent and episodic volcanic and glacial activity on Mars revealed by the High Resolution Stereo Camera
Jaumann, R.; Head, J. W.; Neukum, G. +9 more
The large-area coverage at a resolution of 10-20metres per pixel in colour and three dimensions with the High Resolution Stereo Camera Experiment on the European Space Agency Mars Express Mission has made it possible to study the time-stratigraphic relationships of volcanic and glacial structures in unprecedented detail and give insight into the g…
Perennial water ice identified in the south polar cap of Mars
Sotin, C.; Drossart, Pierre; Forni, O. +39 more
The inventory of water and carbon dioxide reservoirs on Mars are important clues for understanding the geological, climatic and potentially exobiological evolution of the planet. From the early mapping observation of the permanent ice caps on the martian poles, the northern cap was believed to be mainly composed of water ice, whereas the southern …
Solar Wind-Induced Atmospheric Erosion at Mars: First Results from ASPERA-3 on Mars Express
Kallio, E.; Fedorov, A.; Budnik, E. +42 more
The Analyzer of Space Plasma and Energetic Atoms (ASPERA) on board the Mars Express spacecraft found that solar wind plasma and accelerated ionospheric ions may be observed all the way down to the Mars Express pericenter of 270 kilometers above the dayside planetary surface. This is very deep in the ionosphere, implying direct exposure of the mart…
Performance and surface scattering models for the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS)
Gurnett, D. A.; Johnson, W. T. K.; Orosei, R. +10 more
The primary scientific objective of the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS), which will be on board Mars Express mission scheduled for launch in 2003, is to map the distribution and depth of the liquid water/ice interface in the upper kilometres of the crust of Mars. MARSIS will also provide unique information to he…
Ion loss on Mars caused by the Kelvin Helmholtz instability
Kallio, E.; Barabash, S.; Gunell, H. +8 more
Mars Global Surveyor detected cold electrons above the Martian ionopause, which can be interpreted as detached ionospheric plasma clouds. Similar observations by the Pioneer Venus Orbiter electron temperature probe showed also extreme spatial irregularities of electrons in the form of plasma clouds on Venus, which were explained by the occurrence …
Radar signal simulation: Surface modeling with the Facet Method
Safaeinili, A.; Kofman, W.; Herique, A. +1 more
A major finding in exploration of Mars is the indication that a large quantity of water has been present on Mars. To discover the distribution of this quantity of water, the Mars Express spacecraft is carrying a spaceborne radar sounder, called Mars Advance Radar for Subsurface and Ionospheric Sounding (MARSIS), in order to map Mars subsurface die…
Evolution of the Martian atmosphere and hydrosphere: Solar wind erosion studied by ASPERA-3 on Mars Express
Lundin, Rickard; Barabash, Stanislav
The evolution of the Martian atmosphere and the potential existence of a past hydrosphere is a scientific issue of great interest in planetary research. Although the first missions to Mars had a focus on surface features and atmospheric properties, some of the missions (e.g., The Soviet Mars 2, 3 and 5) also carried instruments addressing the sola…
Mars Express and MARSIS
Nielsen, Erling
The Mars Express mission to be launched in 2003 will provide high resolution measurements of the Martian atmosphere and ionosphere. The neutral density, temperature, and composition will be measured, and MARSIS, a low frequency radar experiment, will probe the Martian plasma environment for electron densities in the range from 100 to 3 × 105<…
Visible and infrared spectroscopy of minerals and mixtures with the OMEGA/MARS-EXPRESS instrument
Gendrin, Aline; Bibring, Jean-Pierre; Langevin, Yves +4 more
We present the reflectance measurements made with OMEGA during ground calibration on a selection of minerals and mixtures considered as candidates for constituents of the Mars surface. OMEGA is the visible and infrared mapping spectrometer designed to fly on-board the ESA/MARS-EXPRESS probe. These measurements allow to evaluate the instrument perf…