Search Publications
Morphology, stratigraphy, and mineralogical composition of a layered formation covering the plateaus around Valles Marineris, Mars: Implications for its geological history
Le Mouélic, S.; Bibring, J. -P.; Jaumann, R. +5 more
An extensive layered formation covers the high plateaus around Valles Marineris. Mapping based on HiRISE, CTX and HRSC images reveals these layered deposits (LDs) crop out north of Tithonium Chasma, south of Ius Chasma, around West Candor Chasma, and southwest of Juventae Chasma and Ganges Chasma. The estimated area covered by LDs is ∼42,300 km
Negative ions in the Enceladus plume
Lewis, G. R.; Coates, A. J.; Jones, G. H. +6 more
During Cassini's Enceladus encounter on 12th March 2008, the Cassini Electron Spectrometer, part of the CAPS instrument, detected fluxes of negative ions in the plumes from Enceladus. It is thought that these ions include negatively charged water group cluster ions associated with the plume and forming part of the 'plume ionosphere'. In this paper…
Threshold of wave generation on Titan’s lakes and seas: Effect of viscosity and implications for Cassini observations
Lorenz, Ralph D.; Lunine, Jonathan I.; Newman, Claire
Motivated by radar and near-infrared data indicating that Titan's polar lakes are extremely smooth, we consider the conditions under which a lake surface will be ruffled by wind to form capillary waves. We evaluate laboratory data on wind generation and derive, without scaling for surface tension effects, a threshold for pure methane/ethane of ∼0.…
Magnetic anomalies near Apollinaris Patera and the Medusae Fossae Formation in Lucus Planum, Mars
Williams, David A.; Langlais, Benoit; Poulet, Francois +3 more
The nature of strong martian crustal field sources is investigated by mapping and modeling of Mars Global Surveyor magnetometer data near Apollinaris Patera, a previously proposed volcanic source, supplemented by large-scale correlative studies. Regional mapping yields evidence for positive correlations of orbital anomalies with both Apollinaris P…
Venus night airglow: Ground-based detection of OH, observations of O 2 emissions, and photochemical model
Krasnopolsky, Vladimir A.
Venus nightglow was observed at NASA IRTF using a high-resolution long-slit spectrograph CSHELL at LT = 21:30 and 4:00 on Venus. Variations of the O 2 airglow at 1.27 µm and its rotational temperature are extracted from the observed spectra. The mean O 2 nightglow is 0.57 MR at 21:30 at 35°S-35°N, and the temperature in…
Compositional heterogeneity of Asteroid 4 Vesta’s southern hemisphere: Implications for the Dawn mission
Nathues, Andreas; Li, Jian-Yang; Reddy, Vishnu +3 more
High signal-to-noise, rotationally-resolved spectra of Asteroid 4 Vesta's southern hemisphere from the 2007 opposition were used to constrain its compositional and mineralogical variations. The spectra were rotationally-phased using closely timed HST observations of Vesta by Li et al. (Li, J.-Y., McFadden, L.A., Thomas, P.C., Mutchler, M.J., Parke…
Simulating the density and thermal structure of the middle atmosphere (∼80-130 km) of Mars using the MGCM-MTGCM: A comparison with MEX/SPICAM observations
Smith, M. D.; Forget, F.; Montmessin, F. +4 more
The objective of this work is to advance the understanding of the structure and dynamics of the middle altitude region of the martian atmosphere. While numerous advancements have been made in the level of scientific understanding of Mars's upper and lower atmospheres over the past several decades, insight into the mechanisms of the middle atmosphe…
The source of widespread 3-µm absorption in Jupiter’s clouds: Constraints from 2000 Cassini VIMS observations
Sromovsky, L. A.; Fry, P. M.
The Cassini flyby of Jupiter in 2000 provided spatially resolved spectra of Jupiter's atmosphere using the Visual and Infrared Mapping Spectrometer (VIMS). A prominent characteristic of these spectra is the presence of a strong absorption at wavelengths from about 2.9 µm to 3.1 µm, previously noticed in a 3-µm spectrum obtained b…
Indications of brine related local seepage phenomena on the northern hemisphere of Mars
Möhlmann, D.; Kereszturi, A.; Berczi, Sz. +5 more
Springtime low albedo features, called Dark Dune Spots, on the seasonal frost covered dunes on Mars between 77°N and 84°N latitude have been analyzed. Two groups of these spots have been identified: "small" and "large" ones, where large spots have diameters above 4 m, and complex internal structure. From these "large" spots branching seepage-like …
Elastic ice shells of synchronous moons: Implications for cracks on Europa and non-synchronous rotation of Titan
Goldreich, Peter M.; Mitchell, Jonathan L.
A number of synchronous moons are thought to harbor water oceans beneath their outer ice shells. A subsurface ocean frictionally decouples the shell from the interior. This has led to proposals that a weak tidal or atmospheric torque might cause the shell to rotate differentially with respect to the synchronously rotating interior. Applications al…