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Tailward flow of energetic neutral atoms observed at Mars
Kallio, E.; Barabash, S.; Holmström, M. +7 more
The ASPERA-3 experiment on Mars Express provides the first measurements of energetic neutral atoms (ENAs) from Mars. These measurements are used to study the global structure of the interaction of the solar wind with the Martian atmosphere. In this study we describe the tailward ENA flow observed at the nightside of Mars. After characterizing ener…
Cyclostrophic winds from the Visible and Infrared Thermal Imaging Spectrometer temperature sounding: A preliminary analysis
Drossart, P.; Piccioni, G.; Grassi, D. +4 more
Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) onboard the Venus Express spacecraft has been operating since April 2006 providing new observations of the temperature structure of Venus mesosphere (60-95 km). Zonal winds in the middle atmosphere of Venus have been retrieved from VIRTIS temperature profiles using the cyclostrophic approx…
Venus Express observations of an atypically distant bow shock during the passage of an interplanetary coronal mass ejection
Russell, C. T.; Zhang, T. L.; Glassmeier, K. -H. +10 more
On 10-11 September 2006 the Venus Express magnetometer detected a very strong Interplanetary Coronal Mass Ejection (ICME) event with an average field about 2 times higher than that of a typical ICME at 0.72 AU. While the effective obstacle to the solar wind is compressed to a smaller dimension during this ICME event, the bow shock is located far u…
Whistler mode waves from lightning on Venus: Magnetic control of ionospheric access
Russell, C. T.; Wei, H. Y.; Zhang, T. L.
The fluxgate magnetometer on Venus Express samples the magnetic field near periapsis at 128 Hz. Bursts of plane-polarized magnetic waves in the vicinity of 100 Hz are observed propagating at small angles to the magnetic field. The magnetic field is generally horizontal in the region around periapsis, located at high northern latitudes. When the ma…
Spatial variability of carbon monoxide in Venus' mesosphere from Venus Express/Visible and Infrared Thermal Imaging Spectrometer measurements
Irwin, P. G. J.; Drossart, P.; Piccioni, G. +6 more
Observations of Venus' mesosphere by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS)-M instrument of Venus Express have been used to investigate the spatial distribution of CO above Venus' nightside cloud tops by fitting the CO absorption in the (1-0) CO band around 4.7 µm. We find little spatial variation in the abundance of …
Tailward flow of energetic neutral atoms observed at Venus
Kallio, E.; Barabash, S.; Gunell, H. +7 more
The Analyzer of Space Plasma and Energetic Atoms (ASPERA-4) experiment on Venus Express provides the first measurements of energetic neutral atoms (ENAs) from Venus. The results improve our knowledge on the interaction of the solar wind with a nonmagnetized planet and they present an observational constraint to existing plasma models. We character…
Dust haze in Valles Marineris observed by HRSC and OMEGA on board Mars Express
Bibring, J. -P.; Poulet, F.; Bellucci, G. +9 more
We present analysis of a bright haze observed inside Valles Marineris, which formed in mid northern spring. The data were collected by the High Resolution Stereo Camera (HRSC) and the imaging spectrometer, Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité (OMEGA), aboard Mars Express. This study provides a case example of the power…
Predictions of the electrical conductivity and charging of the cloud particles in Jupiter's atmosphere
O'Brien, K.; Whitten, R. C.; Borucki, W. J. +1 more
The electrical conductivity and electrical charge on cloud particles (composed of ammonia, ammonium hydrosulfide, and water) in the atmosphere of Jupiter are computed for pressures between 5.5 and 0.1 bars. The source of ionization is galactic cosmic rays (GCR). The distribution of charge among the various reservoirs is a function of altitude and …
Venus surface data extraction from VIRTIS/Venus Express measurements: Estimation of a quantitative approach
Drossart, Pierre; Piccioni, Giuseppe; Haus, Rainer +2 more
Nightside emission measurements of the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the Venus Express spacecraft were used to estimate the potential for surface data extraction. A selection of orbits over the northern hemisphere was performed for footprints that cover different scales of surface elevation variations. A correction …
MARSIS subsurface radar investigations of the South Polar reentrant Chasma Australe
Gurnett, D. A.; Farrell, W. M.; Plaut, J. J. +12 more
The Mars Express/Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) has conducted the first-ever subsurface probing of the south polar layered deposits (SPLD) revealing internal structure that is rich in detail. We report on subsurface features detected from a set of orbits that passed over the largest of the south polar reentran…