Search Publications
Sequence and relative timing of large lakes in Gale crater (Mars) after the formation of Mount Sharp
Mangold, Nicolas; Williams, Rebecca M. E.; Palucis, Marisa C. +6 more
The quantification of lake levels in Gale crater is important to define the hydrologic and climatic history experienced by the sedimentary deposits found by Curiosity. We propose that there were at least three major lake stands within Gale, each persisted >1000 years, and all occurred after Mount Sharp reached close to its current topographic f…
Influence of Venus topography on the zonal wind and UV albedo at cloud top level: The role of stationary gravity waves
Bertaux, Jean-Loup; Fedorova, A.; Lebonnois, S. +6 more
Based on the analysis of UV images (at 365 nm) of Venus cloud top (altitude 67 ± 2 km) collected with Venus Monitoring Camera on board Venus Express (VEX), it is found that the zonal wind speed south of the equator (from 5°S to 15°S) shows a conspicuous variation (from -101 to -83 m/s) with geographic longitude of Venus, correlated with the underl…
Recent shallow moonquake and impact-triggered boulder falls on the Moon: New insights from the Schrödinger basin
Head, James W.; Kiran Kumar, A. S.; Amitabh +8 more
Shallow moonquakes are thought to be of tectonic origin. However, the geologic structures responsible for these moonquakes are unknown. Here we report sites where moonquakes possibly occurred along young lobate scarps in the Schrödinger basin. Our analysis of Lunar Reconnaissance Orbiter and Chandrayaan-1 images revealed four lobate scarps in diff…
Geologic context of recurring slope lineae in Melas and Coprates Chasmata, Mars
McEwen, Alfred; Chojnacki, Matthew; Ojha, Lujendra +3 more
One of the major Mars discoveries of recent years is the existence of recurring slope lineae (RSL), which suggests that liquid water occurs on or near the surface of Mars today. These dark and narrow features emerge from steep, rocky exposures and incrementally grow, fade, and reform on a seasonal basis and are detected in images from the High Res…
Composition, seasonal change, and bathymetry of Ligeia Mare, Titan, derived from its microwave thermal emission
Lorenz, R. D.; Karatekin, O.; Janssen, M. A. +8 more
For the last decade, the passive radiometer incorporated in the Cassini RADAR has recorded the 2.2 cm wavelength thermal emission from Titan's seas. In this paper, we analyze the radiometry observations collected from February 2007 to January 2015 over one of these seas, Ligeia Mare, with the goal of providing constraints on its composition, bathy…
A cold-wet middle-latitude environment on Mars during the Hesperian-Amazonian transition: Evidence from northern Arabia valleys and paleolakes
Moore, Jeffrey M.; Wilson, Sharon A.; Howard, Alan D. +1 more
The growing inventory of post-Noachian fluvial valleys may represent a late, widespread episode of aqueous activity on Mars, contrary to the paradigm that fluvial activity largely ceased around the Noachian-Hesperian boundary. Fresh shallow valleys (FSVs) are widespread from ~30 to 45° in both hemispheres with a high concentration in northern Arab…
Setting constraints on the nature and origin of the two major hydrous sulfates on Mars: Monohydrated and polyhydrated sulfates
Liu, Yang; Wang, Alian; Jolliff, Bradley L. +1 more
Monohydrated Mg sulfate (MgSO4·H2O) and polyhydrated sulfate are the most common and abundant hydrous sulfates observed thus far on Mars. They are widely distributed and coexist in many locations. On the basis of results from two new sets of experiments, in combination with past experimental studies and the subsurface salt mi…
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…