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…
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…
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…
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…
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…
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…