Search Publications
Seasonal and Geographical Variability of the Martian Ionosphere From Mars Express Observations
González-Galindo, F.; Němec, F.; Tellmann, S. +4 more
We study the seasonal and geographical variability of the peak electron density and the altitude of the main ionospheric peak at Mars. For this purpose, we use the data obtained by the ESA Mars Express mission, namely by the radar MARSIS and the radio occultation experiment MaRS. The accumulation of data during the long lifetime of Mars Express pr…
The Composition of the South Polar Cap of Mars Derived From Orbital Data
Wieczorek, M. A.; Broquet, A.; Fa, W.
The flexure of the lithosphere under stresses imposed by the geologically young south polar cap is one of the few clues we have regarding the south polar cap composition and the present-day thermal state of Mars. Here, we combine radar, gravity, and topography data with a flexural loading model to estimate the bulk density (ρ) and average real die…
Morphology, Morphometry and Distribution of Isolated Landforms in Southern Chryse Planitia, Mars
Fawdon, Peter; Balme, Matthew R.; McNeil, Joseph D. +1 more
The margin of Chryse Planitia, Mars, contains >105 kilometer scale mesas, buttes, and plateaus ("mounds"), many of which are found in and around Oxia Planum, the ExoMars 2022 Rover landing site. Despite this, their origins and evolution are unknown. We have analyzed the morphologies and morphometries of 14,386 individual mounds to: (…
On the Effect of Magnetospheric Shielding on the Lunar Hydrogen Cycle
Farrell, W. M.; Tucker, O. J.; Poppe, A. R.
The global distribution of surficial hydroxyl on the Moon is hypothesized to be derived from the implantation of solar wind protons. As the Moon traverses the geomagnetic tail, it is generally shielded from the solar wind; therefore, the concentration of hydrogen is expected to decrease during full Moon. A Monte Carlo approach is used to model the…
ExoMars TGO/NOMAD-UVIS Vertical Profiles of Ozone: 2. The High-Altitude Layers of Atmospheric Ozone
Thomas, Ian; Daerden, Frank; Ristic, Bojan +12 more
Solar occultations performed by the Nadir and Occultation for MArs Discovery (NOMAD) ultraviolet and visible spectrometer (UVIS) onboard the ExoMars Trace Gas Orbiter (TGO) have provided a comprehensive mapping of atmospheric ozone density. The observations here extend over a full Mars year (MY) between April 21, 2018 at the beginning of the TGO s…
Lava Flow Eruption Conditions in the Tharsis Volcanic Province on Mars
Christensen, P. R.; Peters, S. I.; Clarke, A. B.
Volcanism has played a major role in modifying the Martian surface. The Tharsis volcanic province dominates the western hemisphere of the planet with numerous effusive volcanic constructs and deposits. Here, we present the results of an in-depth study aimed at characterizing and modeling the emplacement conditions of 40 lava flows in the Tharsis v…
Dielectric Properties of the Medusae Fossae Formation and Implications for Ice Content
Campbell, Bruce A.; Morgan, Gareth A.; Watters, Thomas R.
The extensive Medusae Fossae Formation (MFF) along the dichotomy boundary on Mars has geologic features indicative of wind erosion of low density material. There is evidence suggesting a water ice component, but with considerable uncertainty linked to the unknown MFF porosity and compaction behavior. We use SHARAD radar sounder data to estimate th…
Jupiter's Great Red Spot: Strong Interactions With Incoming Anticyclones in 2019
Hansen, C. J.; Hueso, R.; Sánchez-Lavega, A. +19 more
Jupiter's Great Red Spot (GRS), a giant anticyclone, is the largest and longest lived of all the vortices observed in planetary atmospheres. During its history, the GRS has shrunk to half its size since 1879, and encountered many smaller anticyclones and other dynamical features that interacted in a complex way. In 2018-2020, while having a histor…
A Global and Seasonal Perspective of Martian Water Vapor From ExoMars/NOMAD
Aoki, S.; Vandaele, A. C.; Daerden, F. +18 more
Slightly less than a Martian Year of nominal science (March 2018-January 2020) with the ExoMars Trace Gas Orbiter has furthered the ongoing investigation of dayside water vapor column abundance. These dayside observations span latitudes between 75°S and 75°N, and all longitudes, which can provide global snapshots of the total water column abundanc…
Isotopic Composition of CO2 in the Atmosphere of Mars: Fractionation by Diffusive Separation Observed by the ExoMars Trace Gas Orbiter
Montmessin, Franck; Belyaev, Denis A.; Fedorova, Anna A. +11 more
Isotopic ratios in atmospheric CO2 are shaped by various processes throughout Mars' history, and can help understand what the atmosphere of early Mars was like to sustain liquid water on its surface. In this study, we monitor the O and C isotopic composition of CO2 between 70 and 130 km for more than half a Martian year using…