Search Publications
Valles Marineris dune sediment provenance and pathways
Wray, James J.; Chojnacki, Matthew; Moersch, Jeffrey E. +1 more
Although low-albedo sand is a prevalent component of the martian surface, sources and pathways of the sands are uncertain. As one of the principal present-day martian sediment sinks, the Valles Marineris (VM) rift system hosts a diversity of dune field populations associated with a variety of landforms that serve as potential sediment sources, inc…
Timescales of fluvial activity and intermittency in Milna Crater, Mars
Head, James W.; Fassett, Caleb I.; Buhler, Peter B. +1 more
Milna Crater, Mars (23.4S, 12.3W) exhibits signs of fluvial modification early in Mars history, including a large multi-lobed fan deposit cut by several sinuous valleys. We describe the past hydrologic conditions in Milna and the surrounding area, including a potential lake with a volume of 50 km3. We also introduce new methods (i) to c…
A radar map of Titan Seas: Tidal dissipation and ocean mixing through the throat of Kraken
Soderblom, Jason M.; Kirk, Randolph L.; Lorenz, Ralph D. +9 more
We present a radar map of the Titan’s seas, with bathymetry estimated as proportional to distance from the nearest shore. This naïve analytic bathymetry, scaled to a recent radar sounding of Ligeia Mare, suggests a total liquid volume of ∼32,000 km3, at the low end of estimates made in 2008 when mapping coverage was incomplete. We note …
Modeling the microphysics of CO2 ice clouds within wave-induced cold pockets in the martian mesosphere
Montmessin, F.; Spiga, A.; Lefèvre, F. +2 more
Mesospheric CO2 ice clouds on Mars are simulated with a 1D microphysical model, which includes a crystal growth rate adapted to high supersaturations encountered in the martian mesosphere. Observational constraints (crystal radius and opacity) exist for these clouds observed during the day around the equator at ∼60-80 km altitude. Night…
The methane mole fraction in Titan’s stratosphere from DISR measurements during the Huygens probe’s descent
Bézard, Bruno
We present a determination of the methane mole fraction in Titan's stratosphere using spectral measurements by the Upward Looking Infrared Spectrometer (ULIS) of the Descent Imager/Spectral Radiometer (DISR) aboard the Huygens probe. We analyzed the 1.4-µm band of methane for which a complete linelist, down to very low intensities, was recen…
Cassini-VIMS observations of Saturn's main rings: I. Spectral properties and temperature radial profiles variability with phase angle and elevation
Brown, R. H.; Clark, R. N.; Nicholson, P. D. +10 more
The spectral properties and thermal behavior of Saturn's rings are determined from a dataset of ten radial mosaics acquired by Cassini-VIMS (Visual and Infrared Mapping Spectrometer) between October 29th 2004 and January 27th 2010 with phase angle ranging between 5.7° and 132.4° and elevation angles between -23.5° and 2.6°. These observations, aft…
Comprehensive analysis of glaciated martian crater Greg
Mangold, Nicolas; Forget, François; Berman, Daniel C. +2 more
The 66-km diameter martian crater, Greg, east of Hellas, hosts various distinctive features, including dendritic valleys filled with chevron-textured masses (south wall), and lobate tongues a few kilometers long (north wall). We analyze these features by various quantitative techniques to illuminate martian geologic and climatic history. Crater re…
Lunar polar craters - Icy, rough or just sloping?
Smith, David; Eke, Vincent R.; Bartram, Sarah A. +2 more
Circular Polarisation Ratio (CPR) mosaics from Mini-SAR on Chandrayaan-1 and Mini-RF on LRO are used to study craters near to the lunar north pole. The look direction of the detectors strongly affects the appearance of the crater CPR maps. Rectifying the mosaics to account for parallax also significantly changes the CPR maps of the crater interior…
Noncircular features in Saturn's rings II: The C ring
Nicholson, Philip D.; French, Richard G.; Hedman, Matthew M. +5 more
We present a comprehensive survey of sharp-edged features in Saturn's C ring, using data from radio and stellar occultation experiments carried out by the Cassini spacecraft over a period of more than five years. Over 100 occultations are included in the combined data set, enabling us to identify systematic radial perturbations as small as 200 m o…
Mineralogy of young lunar mare basalts: Assessment of temporal and spatial heterogeneity using M3 data from Chandrayaan-1
Murty, Sripada V. S.; Srivastava, Neeraj; Varatharajan, Indhu
A comparative assessment of the mineralogy of young basalts (∼1.2 Ga to ∼2.8 Ga) from the western nearside, Moscoviense basin, and the Orientale basin of the Moon has been made using Level 2 Moon Mineralogy Mapper (M3) data from the Chandrayaan-1 mission. Spectral data characteristics of the individual units have been generated from fre…