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Estimation of the total electron content of the Martian ionosphere using radar sounder surface echoes
Gim, Yonggyu; Kofman, Wlodek; Herique, Alain +5 more
The Martian ionosphere's local total electron content (TEC) and the neutral atmosphere scale height can be derived from radar echoes reflected from the surface of the planet. We report the global distribution of the TEC by analyzing more than 750,000 echoes of the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS). This is the fi…
Mobility and topographic effects for large Valles Marineris landslides on Mars
Mangeney, A.; Lucas, A.
Recent experiments on dry granular flows over horizontal plane bare some similarities with large Martian landslides observed in Valles Marineris (VM). However, Martian normalized runout are twice as large as those that observed in dry granular flow experiments. Numerical simulations on theoretical 2D and real 3D topographies reconstructed from rem…
Stability of hydrated minerals on Mars
Mustard, John F.; Bibring, Jean-Pierre; Poulet, François +7 more
The validity of recent identification of various hydrated minerals (kieserite, gypsum, hexahydrite, nontronite, chamosite, and montmorillonite) on Mars was assessed by exposing these minerals to simulated Martian surface conditions of atmospheric composition and pressure, temperature, and ultraviolet light irradiation. When exposed to such conditi…
Absorption of MARSIS radar signals: Solar energetic particles and the daytime ionosphere
Espley, Jared R.; Plaut, Jeffrey J.; Farrell, William M. +5 more
We present observations from the subsurface sounding mode of the MARSIS instrument onboard Mars Express that imply radar wave absorption because of increased amounts of ionization in the upper Martian atmosphere during the fall of 2005. On at least two occasions these radar disruptions lasted for several days and we find that these periods are cor…
On Martian nitrogen dayglow emission observed by SPICAM UV spectrograph/Mars Express
Leblanc, F.; Bertaux, J. L.; Chaufray, J. Y.
SPICAM UV spectrograph on board Mars Express has reported, for the first time, the identification of the N2 VK (0,5) and (0,6) band emissions in the Martian dayglow. The derived exospheric temperature of the N2 species in the upper Martian atmosphere is equal to 190 +/- 51 K for areocentric longitudes between 100° and 171° an…
Numerical modeling of the magnetic topology near Mars auroral observations
Barabash, S.; Lundin, R.; Winningham, J. D. +6 more
Magnetohydrodynamic (MHD) simulations of the Mars magnetic field topology are presented for the auroral observations reported from the Mars Express SPICAM instrument. It is found that the field lines closest to the assumed emission location are open. That is, they are connected to the interplanetary magnetic field, thus allowing access for solar w…