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Gypsum, opal, and fluvial channels within a trough of Noctis Labyrinthus, Mars: Implications for aqueous activity during the Late Hesperian to Amazonian
Weitz, Catherine M.; Grant, John A.; Bishop, Janice L.
We investigate in detail the morphology, mineralogy, and stratigraphy of light-toned deposits within one trough of Noctis Labyrinthus, centered at -6.8°N, 261.1°E. CRISM spectra taken from light-toned layered deposits in the northern portion of the trough exhibit absorptions around 1.41, 1.92 and 2.21 µm, consistent with mixtures of opal and…
Self-consistent retrieval of temperature profiles and cloud structure in the northern hemisphere of Venus using VIRTIS/VEX and PMV/VENERA-15 radiation measurements
Kappel, D.; Arnold, G.; Haus, R.
Improved radiative transfer simulation and multi-window retrieval procedures (MWR) are described that are applied to investigate thermal structure and cloud features in the nightside atmosphere of Venus over the northern hemisphere. Comparative analyses of spectroscopic data, which were recorded independently in different parts of the infrared spe…
Constraints on Titan's middle atmosphere ammonia abundance from Herschel/SPIRE sub-millimetre spectra
Hartogh, P.; Lellouch, E.; Irwin, P. G. J. +6 more
Sub-millimetre spectra measured with Herschel's SPIRE Fourier Transform Spectrometer were used to search for ammonia (NH3) in Titan's stratosphere. Observations were taken during 2010 and 2011, just after Titan's northern spring equinox, which occurred in mid-2009. In our analysis we used high spectral resolution data (0.074 cm-1
Evolution of the Io footprint brightness I: Far-UV observations
Saur, J.; Bonfond, B.; Clarke, J. T. +6 more
The Io footprint (IFP) is a set of auroral spots and an extended tail resulting from the strong interaction between Io and the Jovian magnetosphere. For the first time, we present measurements of the brightness and precipitated power for each individual spot, using the image database gathered from 1997 to 2009 with the Hubble Space Telescope in th…
Co-registration of laser altimeter tracks with digital terrain models and applications in planetary science
Oberst, J.; Gläser, P.; Haase, I. +1 more
We have derived algorithms and techniques to precisely co-register laser altimeter profiles with gridded Digital Terrain Models (DTMs), typically derived from stereo images. The algorithm consists of an initial grid search followed by a least-squares matching and yields the translation parameters at sub-pixel level needed to align the DTM and the …
Mars surface phase function constrained by orbital observations
Vincendon, Mathieu
The bidirectional photometric properties of the surface of Mars describe how remote measurements of surface reflectance can be linked to hemispherical albedo used for energy balance calculations. A simple Lambert's law is frequently assumed for global data processing, even though several local studies have revealed the complexity of Mars surface p…
Scaling relationships and concavity of small valley networks on Mars
Fassett, Caleb I.; Penido, Julita C.; Som, Sanjoy M.
Valley networks are widely interpreted as the preserved erosional record of water flowing across the martian surface. The manner in which valley morphometric properties scale with drainage area has been widely examined on Earth. Earlier studies assessing these properties on Mars have suggested that martian valleys are morphometrically distinct fro…
The origin of Phobos grooves from ejecta launched from impact craters on Mars: Tests of the hypothesis
Head, James W.; Ramsley, Kenneth R.
The surface of the martian moon Phobos is characterized by parallel and intersecting grooves that bear resemblance to secondary crater chains observed on planetary surfaces. Murray (2011) has hypothesized that the main groove-forming process on Phobos is the intersection of Phobos with ejecta from primary impact events on Mars to produce chains of…
Composition of Titan's upper atmosphere from Cassini UVIS EUV stellar occultations
Zhang, X.; Shemansky, D. E.; Yung, Y. L. +1 more
Identifying seasonal and spatial variability in Titan's atmospheric structure is a key factor in improving theoretical models of atmospheric loss and understanding the physical processes that control the loss rate. In this work, the extreme ultraviolet (EUV) stellar occultation lightcurves from the Cassini Ultraviolet Imaging Spectrograph (UVIS) e…
Morphotectonic features on Titan and their possible origin
Coustenis, Athena; Solomonidou, Anezina; Bampasidis, Georgios +5 more
Spectro-imaging and radar measurements by the Cassini-Huygens mission suggest that some of the Saturnian satellites may be geologically active and could support tectonic processes. In particular Titan, Saturn's largest moon, possesses a complex and dynamic geology as witnessed by its varied surface morphology resulting from aeolian, fluvial, and p…