Search Publications
Analysis of NASA's DSN Venus Express radio occultation data for year 2014
Gramigna, Edoardo; Tortora, Paolo; Zannoni, Marco +5 more
The Venus Express Radio Science Experiment (VeRa) was part of the scientific payload of the Venus Express (VEX) spacecraft and was targeted at the investigation of Venus' atmosphere, surface, and gravity field as well as the interplanetary medium. This paper describes the methods and the required calibrations applied to VEX-VeRa raw radio occultat…
Super rogue waves at Venusian ionosphere and mantle
El-Shafeay, N. A.; El-Taibany, W. F.; Moslem, W. M. +1 more
Formation of super rogue ion-acoustic wave is suggested as a physical catalyst for the photochemical reaction to form the Venusian ionosphere and its mantle. Based on the observed data at Venus by Pioneer Venus Orbiter (PVO) and Venus Express (VEX), we constructed our models. The plasma model of the ionosphere consists of two positive ions fluid (…
Plasma vortices driven by magnetic torsion generated by electric currents in non-magnetic planetary wakes
Flandes, Alberto; Durand-Manterola, Héctor Javier
In non-collisional magnetised astrophysical plasmas, vortices can form as it is the case of the Venus plasma wake where Lundin et al. (2013) identified a large vortex through the integration of data of many orbits from the Venus Express (VEX) spacecraft. On the one hand, our purpose is to develop a theoretical foundation in order to explain the oc…
Ionic loss from Venus upper ionosphere via plasma wake
Moslem, W. M.; Elsheikh, I. A.; Tolba, R. E. +2 more
Recent observations have detected significant escape of ions from the Venusian ionosphere. The measurements indicate that the composition of the escaping mix of ions may reach a critical ratio of H+ : O+ ≈ 2 : 1 , suggesting that it originated in water molecules, in line with the observed dryness of the planet. In this work, …
Contribution from SOIR/VEX to the updated Venus International Reference Atmosphere (VIRA)
Vandaele, A. C.; Trompet, L.; Robert, S. +9 more
The SOIR instrument on-board Venus Express is an infrared spectrometer covering the 2.2-4.3 µm spectral region. This instrument allows the detection of several key species of the Venus atmosphere, including CO2, CO, H2O/HDO, HCl, HF and SO2. From the CO2 density measurements, temperature is inferre…
Future dedicated Venus-SGG flight mission: Accuracy assessment and performance analysis
Zheng, Wei; Hsu, Houtse; Zhong, Min +1 more
This study concentrates principally on the systematic requirements analysis for the future dedicated Venus-SGG (spacecraft gravity gradiometry) flight mission in China in respect of the matching measurement accuracies of the spacecraft-based scientific instruments and the orbital parameters of the spacecraft. Firstly, we created and proved the sin…
First geodetic VLBI sessions with the Chinese Deep Space Stations Jiamusi and Kashi
Wang, Guangli; Xu, Dezhen; Dong, Guangliang +2 more
The first three 24-h S/X dual-band geodetic VLBI sessions using two new Chinese Deep Space Stations (CDSSs), Jiamusi and Kashi, and four Chinese VLBI Stations (CVSs), Beijing, Kunming, Seshan, and Urumqi were conducted with the goal of improving the two CDSSs' positions, which were previously known to a few decimeters. Due to the limited frequency…
New results on planetary lightning
Yair, Yoav
We present the latest observations from spacecraft and ground-based instruments in search for lightning activity in the atmospheres of planets in the solar system, and put them in context of previous research. Since the comprehensive book on planetary atmospheric electricity compiled by Leblanc et al. (2008), advances in remote sensing technology …
Refinements in the data analysis of VIRTIS-M-IR Venus nightside spectra
Drossart, Pierre; Piccioni, Giuseppe; Haus, Rainer +2 more
The successful long-duration radiation measurements performed by the VIRTIS instrument aboard ESA's Venus Express spacecraft have provided an excellent collection of atmospheric and surface data that stand out due to their high temporal and spatial coverage of the planet and due to a high diversity of measurement and environmental conditions. A de…
Quasi-periodic frequency fluctuations observed during coronal radio sounding experiments 1991-2009
Pätzold, M.; Bird, M. K.; Efimov, A. I. +5 more
Coronal radio sounding experiments were carried out using the dual-frequency signals of the spacecraft Ulysses, Galileo, Mars Express, Venus Express, and Rosetta. The change in differential frequency recorded at the NASA and ESA ground stations, a quantity sensitive only to the plasma along the radio ray path from spacecraft to receiver, has been …