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Shocklets and Short Large Amplitude Magnetic Structures (SLAMS) in the High Mach Foreshock of Venus
Raptis, Savvas; Karlsson, Tomas; Plaschke, Ferdinand +16 more
Shocklets and short large-amplitude magnetic structures (SLAMS) are steepened magnetic fluctuations commonly found in Earth's upstream foreshock. Here we present Venus Express observations from the 26th of February 2009 establishing their existence in the steady-state foreshock of Venus, building on a past study which found SLAMS during a substant…
Gravity Wave Modulations at the Lower Altitudes of Venus Ionosphere
Choudhary, R. K.; Imamura, T.; Ambili, K. M. +2 more
Using measurements from radio science experiments onboard Venus Express and Akatsuki orbiter, we explore factors that control the occurrence and spatial structure of the electron density enhancement at lower altitudes (V0 layer) in the Venus ionosphere. Results suggest that the Gravity Waves (GWs) play a crucial role in determining the …
Hubble Detects the Start of a New Saturn Ring Spoke Season
Nicholson, Philip D.; Hedman, Matthew M.; Showalter, Mark R. +4 more
Saturn's ring spokes typically appear over an 8-year duration centered on equinox. Hubble Space Telescope observations in 2021 indicate the beginning of a new spoke season as Saturn approaches equinox in 2025. The spokes show increased contrast and longevity in 2022, persisting for up to 11 hours. The spokes are visible from UV to near-IR and are …
Probing the Magnetospheric Generator of Quiet Electrostatic Auroral Arcs From Ground Based Optical Observations and Magnetosphere-ionosphere Coupling Modeling
De Keyser, J.; Lamy, H.; Cessateur, G. +2 more
Observations of a quiet electrostatic auroral arc by the ALIS network on 5 March 2008 are used to infer a two-dimensional map of the flux of precipitating energy. Among a family of numerical solutions of a stationary magnetosphere—ionosphere coupling model in which the origin of the arc is a magnetospheric generator interface, we find which genera…
The Deuterium Isotopic Ratio of Water Released From the Martian Caps as Measured With TGO/NOMAD
Vandaele, Ann Carine; Brines, Adrian; Aoki, Shohei +18 more
We report vertical profiles of water and D/H for one Martian year as measured with the TGO/NOMAD instrument. The observations were performed via solar occultation, providing water profiles up to ∼100 km and D/H up to ∼60 km, with a vertical resolution of 1-2 km. The measurements reveal dramatic variability of water and D/H over short timescales an…
Deducing Lunar Regolith Porosity From Energetic Neutral Atom Emission
Wurz, P.; Galli, A.; Jäggi, N. +6 more
The porosity of the upper layers of regolith is key to the interaction of an airless planetary body with precipitating radiation, but it remains difficult to characterize. One of the effects that is governed by regolith properties is Energetic Neutral Atom (ENA) emission in the form of reflected and neutralized solar wind protons. We simulate this…
The Basal Detectability of an Ice-Covered Mars by MARSIS
Mouginot, J.; Kofman, W.; Hérique, A. +2 more
The detection of anomalously strong relative basal reflectivity beneath the Martian South Polar Layered Deposits (SPLD) from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) has led to hypotheses suggesting the presence of basal materials such as liquid water. Here, we propose a forward approach to assess whether such a high…
Thermal Tides in the Martian Atmosphere Near Northern Summer Solstice Observed by ACS/TIRVIM Onboard TGO
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +8 more
Thermal tides in the Martian atmosphere are analyzed using temperature profiles retrieved from nadir observations obtained by the TIRVIM Fourier-spectrometer, part of the Atmospheric Chemistry Suite onboard the ExoMars Trace Gas Orbiter. The data is selected near the northern summer solstice at solar longitude (LS) 75°-105° of Martian Y…
Parker Solar Probe Imaging of the Night Side of Venus
Lustig-Yaeger, Jacob; Vourlidas, Angelos; Stenborg, Guillermo +14 more
We present images of Venus from the Wide-Field Imager for Parker Solar Probe (WISPR) telescope on board the Parker Solar Probe (PSP) spacecraft, obtained during PSP's third and fourth flybys of Venus on 2020 July 11 and 2021 February 20, respectively. Thermal emission from the surface is observed on the night side, representing the shortest wavele…
Mars-Ward Ion Flows in the Martian Magnetotail: Mars Express Observations
Barabash, Stas; Nilsson, Hans; Rong, Zhaojin +10 more
We investigate Mars-ward planetary ions (O+ and O2+) in the Martian magnetotail that potentially reduce the amount of escaping ions. The global properties of Mars-ward flows in the Martian magnetotail are characterized, based on over 13-years of ion data (May 2007-December 2020) collected by the Analyzer of Space P…