Search Publications
Are the Dorsa Argentea on Mars eskers?
Conway, Susan J.; Butcher, Frances E. G.; Arnold, Neil S.
The Dorsa Argentea are an extensive assemblage of ridges in the southern high latitudes of Mars. They have previously been interpreted as eskers formed by deposition of sediment in subglacial meltwater conduits, implying a formerly more extensive south polar ice sheet. In this study, we undertake the first large-scale statistical analysis of aspec…
Wavelength dependence of scattering properties in the VIS-NIR and links with grain-scale physical and compositional properties
Schmidt, F.; Ehlmann, B. L.; Pilorget, C. +2 more
Surface scattered sunlight carries important information about the composition and microtexture of surface materials, thus enabling tracing back the geological and climatic processes that occurred on the planetary body. Here we perform laboratory spectro-goniometric measurements of granular samples (45-75 µ m fraction) with different composi…
Anatomy of outbursts and quiescent activity of Comet 29P/Schwassmann-Wachmann
Roche, Paul; Mottola, Stefano; Miles, Richard +4 more
Detailed morphological and photometric characterisation of Comet 29P in the optical region is presented comprising: (a) multi-filter observations of the outburst coma in 2010-2012 with the 2.0-m Faulkes Telescopes (FT); (b) high-cadence, high-precision photometry in May-September 2014; and (c) HST observations in March 1996 (WFPC2/F702W filter). O…
Morphologic evidence of subsurface sediment mobilization and mud volcanism in Candor and Coprates Chasmata, Valles Marineris, Mars
Okubo, Chris H.
Populations of distinctive knobs, rings and lobate structures are observed in the Candor and Coprates Chasmata regions of Mars. To interpret the formation mechanisms of these landforms, I investigate their morphologies, facies, superposition and crosscutting relationships using data from the High Resolution Imaging Science Experiment (HiRISE) and …
Dione and Rhea seasonal exospheres revealed by Cassini CAPS and INMS
Waite, J. H.; Teolis, B. D.
A Dione O2 and CO2 exosphere of similar composition and density to Rhea's is confirmed by Cassini spacecraft Ion Neutral Mass Spectrometer (INMS) flyby data. INMS results from three Dione and two Rhea flybys show exospheric spatial and temporal variability indicative of seasonal exospheres, modulated by winter polar gas adsor…
Vertical structure and optical properties of Titan's aerosols from radiance measurements made inside and outside the atmosphere
Karkoschka, Erich; Tomasko, Martin G.; Anderson, Carrie M. +1 more
Prompted by the detection of stratospheric cloud layers by Cassini's Composite Infrared Spectrometer (CIRS; see Anderson, C.M., Samuelson, R.E. [2011]. Icarus 212, 762-778), we have re-examined the observations made by the Descent Imager/Spectral Radiometer (DISR) in the atmosphere of Titan together with two constraints from measurements made outs…
Aerosol properties in the upper haze of Venus from SPICAV IR data
Vandaele, A. C.; Montmessin, F.; Fedorova, A. +5 more
SPICAV IR, a channel of the SPICAV/SOIR suite of instruments onboard Venus Express spacecraft measured spectra in nadir and solar occultation modes in the range of 0.65-1.7 µm. We report results from 222 solar occultations observed from May 2006 to November 2014. The vertical resolution of measurements varies from 1 to 25 km depending on the…
Material transport map of Titan: The fate of dunes
Lorenz, Ralph D.; Turtle, Elizabeth P.; Malaska, Michael J. +3 more
Using SAR data from Cassini's RADAR instrument, we examined the orientations of three terrain units on Titan, bright lineated plains, streak-like plains, and linear dunes. From the overall integrated pattern of their orientation, we were able to determine Titan's global material transport vectors. The analysis indicates that, in both the northern …
Seasonal variability of Saturn's tropospheric temperatures, winds and para-H2 from Cassini far-IR spectroscopy
Fletcher, Leigh N.; Irwin, P. G. J.; Orton, G. S. +2 more
Far-IR 16-1000 µ m spectra of Saturn's hydrogen-helium continuum measured by Cassini's Composite Infrared Spectrometer (CIRS) are inverted to construct a near-continuous record of upper tropospheric (70-700 mbar) temperatures and para-H2 fraction as a function of latitude, pressure and time for a third of a saturnian year (2004-20…
Deciphering the embedded wave in Saturn's Maxwell ringlet
Nicholson, Philip D.; French, Richard G.; McGhee-French, Colleen A. +5 more
The eccentric Maxwell ringlet in Saturn's C ring is home to a prominent wavelike structure that varies strongly and systematically with true anomaly, as revealed by nearly a decade of high-SNR Cassini occultation observations. Using a simple linear "accordion" model to compensate for the compression and expansion of the ringlet and the wave, we de…