Search Publications
Lunar opposition effect as inferred from Chandrayaan-1 M3 data
Shkuratov, Yuriy; Kaydash, Vadym; Korokhin, Viktor +1 more
The shadow-hiding and coherent backscattering enhancement mechanisms are considered to be the major contributors to the brightness opposition effect of the Moon. However, the actual proportions of the mechanisms at different phase angles still remain not well determined. In order to assess the lunar phase function across small phase angles, we uti…
Characterization of middle-atmosphere polar warming at Mars
Forget, F.; Smith, M.; Bougher, S. +3 more
We characterize middle-atmosphere polar warming (PW) using nearly three Martian years of temperature observations by the Mars Climate Sounder. We report the observed structure of PW and share hypotheses as to possible explanations, which have yet to be tested with global dynamical models. In the data, PW manifested between p = 15 Pa and p = 4.8×10…
Experimental investigation into the effects of meteoritic impacts on the spectral properties of phyllosilicates on Mars
Hasegawa, S.; Gavin, P.; Chevrier, V. +2 more
Phyllosilicates have been identified in some of the most highly cratered Noachian terrains on Mars. To study the effects of such impacts on the properties of phyllosilicates, we experimentally shocked six phyllosilicate minerals relevant to the Martian surface: montmorillonite, nontronite, kaolinite, prehnite, chlorite, and serpentine. The shock-t…
Estimates of fluvial erosion on Titan from sinuosity of lake shorelines
Perron, J. Taylor; Tewelde, Yodit; Ford, Peter +2 more
Titan has few impact craters, suggesting that its surface is geologically young. Titan's surface also has abundant landforms interpreted to be fluvial networks. Here we evaluate whether fluvial erosion has caused significant resurfacing by estimating the cumulative erosion around the margins of polar lakes. A scarcity of detailed topographic data …
Evidence for a short period of hydrologic activity in Newton crater, Mars, near the Hesperian-Amazonian transition
Howard, A. D.; Moore, J. M.; Parsons, R. A.
Hesperian/Amazonian-aged valleys and alluvial fans distributed in regional clusters throughout the southern middle- to low-latitudes were formed during a period of fluvial runoff and erosion which acted over a smaller spatial and temporal scale than the older, "classical" Martian valley networks dated to the Noachian-Hesperian boundary. In order t…
Simulations of the latitudinal variability of CO-like and OCS-like passive tracers below the clouds of Venus using the Laboratoire de Météorologie Dynamique GCM
Lebonnois, S.; Marcq, E.
The lower atmosphere of Venus below the clouds is a transitional region between the relatively calm lowermost scale height and the superrotating atmosphere in the cloud region and above. Any observational constraint is then welcome to help in the development of general circulation models of Venus, a difficult task considering the thickness of its …
Exposures of olivine-rich rocks in the vicinity of Ares Vallis: Implications for Noachian and Hesperian volcanism
Mustard, J. F.; Wilson, J. H.
ABSTRACT The igneous evolution of Mars is well represented in stratigraphic settings that transition across major time stratigraphic boundaries. Here we analyze in detail the morphology and composition, determined through visible-near-infrared spectroscopy, of igneous volcanic terrains in Ares Vallis, Mars. Upland plateau units with crater-filling…
Geomorphic signatures of glacial activity in the Alba Patera volcanic province: Implications for recent frost accumulation on Mars
Sinha, Rishitosh K.; Murty, Sripada V. S.
landforms lying within impact craters on Mars have led to the identification of two mechanisms for their formation: (1) intermittent deposition of atmospherically emplaced snow/ice during past spin-axis/orbital conditions and (2) flow of debris-covered ice-rich deposits. The maximum presence of the young ice/snow-rich features (thermal contraction…
Correction to: "Geophysical implications of the long-wavelength topography of the Saturnian satellites"
Nimmo, F.; Thomas, P. C.; Bills, B. G.
A chronology of early Mars climatic evolution from impact crater degradation
Mangold, N.; Ansan, V.; Adeli, S. +2 more
The degradation of impact craters provides a powerful tool to analyze surface processes in the Martian past. Previous studies concluded that large impact craters (20-200 km in diameter) were strongly degraded by fluvial erosion during early Martian history. Our goal is to study the progression of crater degradation through time with a particular e…