Search Publications
Modeling the Jovian magnetic field and its secular variation using all available magnetic field observations
Ridley, Victoria A.; Holme, Richard
We present new models of Jupiter's internal magnetic field and secular variation from all available direct measurements from three decades of spacecraft observation. A regularized minimum norm approach allows the creation of smooth, numerically stable models displaying a high degree of structure. External field from the magnetodisk is modeled iter…
A sedimentary origin for intercrater plains north of the Hellas basin: Implications for climate conditions and erosion rates on early Mars
Mangold, Nicolas; Ori, Gian Gabriele; Salese, Francesco +4 more
Understanding the origin (volcanic or sedimentary) and timing of intercrater plains is crucial for deciphering the geological evolution of Mars. We have produced a detailed geological map of the intercrater plains north of the Hellas basin, based on images from the Mars Express High-Resolution Stereo Camera, the Mars Reconnaissance High-Resolution…
Spheroidal and ellipsoidal harmonic expansions of the gravitational potential of small Solar System bodies. Case study: Comet 67P/Churyumov-Gerasimenko
Reimond, Stefan; Baur, Oliver
Gravitational features are a fundamental source of information to learn more about the interior structure and composition of planets, moons, asteroids, and comets. Gravitational field modeling typically approximates the target body with a sphere, leading to a representation in spherical harmonics. However, small celestial bodies are often irregula…
Phase compensation of MARSIS subsurface sounding data and estimation of ionospheric properties: New insights from SHARAD results
Campbell, Bruce A.; Watters, Thomas R.
Subsurface radar sounding observations by the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) and Shallow Radar (SHARAD) instruments are affected by ionospheric phase distortions that lead to image blurring and delay offsets. Based on experience with SHARAD image correction, we propose that ionospheric blurring in MARSIS radar…
Hydrological and sedimentary analyses of well-preserved paleofluvial-paleolacustrine systems at Moa Valles, Mars
Hauber, Ernst; Di Achille, Gaetano; Ori, Gian Gabriele +2 more
Moa Valles is a well-preserved, likely Amazonian (younger than 2 Ga old), paleodrainage system that is nearly 300 km long and carved into ancient highland terrains west of Idaeus Fossae. The fluvial system apparently originated from fluidized ejecta blankets, and it consists of a series of dam breach paleolakes with associated fan-shaped sedimenta…
Characterization of the permittivity of controlled porous water ice-dust mixtures to support the radar exploration of icy bodies
Thomas, N.; Brouet, Y.; Pommerol, A. +6 more
The internal properties of porous and icy bodies in the solar system can be investigated by ground-penetrating radars (GPRs), like the COmet Nucleus Sounding Experiment by Radiowave Transmission instrument on board the Rosetta spacecraft which has sounded the interior of the nucleus of comet 67P/Churyumov-Gerasimenko. Accurate constraints on the p…
Constraints on the formation and properties of a Martian lobate debris apron: Insights from high-resolution topography, SHARAD radar data, and a numerical ice flow model
Parsons, Reid; Holt, John
Lobate debris aprons (LDAs) are midlatitude deposits of debris-covered ice formed during one or more periods of glaciation during the Amazonian period. However, little is known about the climate conditions that led to LDA formation. We explore a hypothesis in which a single, extended period of precipitation of ice on the steep slopes of Euripus Mo…
Lithospheric flexure and gravity spreading of Olympus Mons volcano, Mars
Williams, D. A.; Platz, T.; Dumke, A. +5 more
The structural architecture of large volcanoes is governed substantially by gravity-driven deformation that is manifest as distinct processes such as basement flexure or volcanic spreading. Temporal effects and the mutual interplay of these processes have been investigated only to a limited extent, and so we present novel numerical models of the t…
A photochemical model of the dust-loaded ionosphere of Mars
Montmessin, F.; O'Brien, K.; Michael, M. +5 more
The ionization of the lower Martian atmosphere and the presence of charged species are fundamental in the understanding of atmospheric electricity phenomena, such as electric discharges, large-scale electric currents, and Schumann resonances. The present photochemical model of the lower ionosphere of Mars (0-70 km) is developed to compute the conc…
Stratigraphy and formation of clays, sulfates, and hydrated silica within a depression in Coprates Catena, Mars
Weitz, Catherine M.; Bishop, Janice L.
We investigate the morphology, mineralogy, and stratigraphy of light-toned layered deposits within a trough of Coprates Catena, centered at -15°N, 300°E. One of the deposits in the eastern portion of the trough contains numerous hydrated minerals, including Al-phyllosilicates, Fe/Mg-phyllosilicates, hydrated silica, hydrated sulfates, jarosite and…