Search Publications
Formation and degradation of chaotic terrain in the Galaxias regions of Mars: implications for near-surface storage of ice
Conway, Susan J.; Gallagher, Colman; Balme, Matt +1 more
Galaxias Chaos is a region of low plateaus separated by narrow fractures - a chaotic terrain. Galaxias Mensae and Galaxias Colles are characterised by mesa and knobby terrains of individual landforms, or small assemblages, separated by plains. Galaxias Chaos has been attributed to ground disturbance due to sublimation in shallow subsurface ice-ric…
Enceladus' near-surface CO2 gas pockets and surface frost deposits
McCord, Thomas B.; Radebaugh, Jani; Combe, Jean-Philippe +4 more
Solid CO2 surface deposits were reported in Enceladus' South Polar Region by Brown et al. (2006). They noted that such volatile deposits are temporary and posited ongoing replenishment. We present a model for this replenishment by expanding on the Matson et al. (2012) model of subsurface heat and chemical transport in Enceladus. Our mod…
Energetic electron measurements near Enceladus by Cassini during 2005-2015
Krupp, N.; Roussos, E.; Khurana, K. K. +9 more
Enceladus is the main source of neutral and charged particles in the Saturnian magnetosphere. The particles originate at more than 100 active geysers forming a plume above the south pole of the moon and are continuously released into Saturn's magnetosphere. Therefore the understanding of the interaction of those particles and the local magnetosphe…
Collapse-driven formation of depressions on comet 67P/Churyumov-Gerasimenko
Leliwa-Kopystynski, J.
The extremely diverse surface of comet 67P/Churyumov-Gerasimenko contains a large number of depressions or craters of very different scales. Among the most prominent are two large roughly circular depressions, each with radii of several hundred meters. In this work a model for the formation of the depressions is proposed. It is based on the theory…
Energy deposition and ion production from thermal oxygen ion precipitation during Cassini's T57 flyby
Smith, Michael; Snowden, Darci; Jimson, Theodore +1 more
Cassini's Radio Science Investigation (RSS) and Langmuir Probe observed abnormally high electron densities in Titan's ionosphere during Cassini's T57 flyby. We have developed a three-dimensional model to investigate how the precipitation of thermal magnetospheric O+ may have contributed to enhanced ion production in Titan's ionosphere. …
The light-toned stratified sedimentary rock exposures in western Juventae Chasma, Mars, in context
Sarkar, Ranjan; Edgett, Kenneth S.; Singh, Pragya +1 more
Juventae Chasma, an isolated depression northeast of the Valles Marineris trough system, hosts four mounds of light-toned, layered materials. These are erosional remnants interpreted to consist of sedimentary rocks. The geological setting of Juventae Chasma is a complex amalgamation of terrains and surfaces of different morphologies, ages, and str…
Determination of the coma dust back-scattering of 67P for phase angles from 1.2° to 75°
Fink, Uwe; Doose, Lyn
A phase curve is derived for the dust coma of comet 67P/Churyumov-Gerasimenko (67P) from 1.2° to 74° using images from the OSIRIS camera system on board the Rosetta mission during the period 2014 July 25 to 2015 February 23 as the spacecraft approached the comet. We analyzed 123 images of the continuum filter at 612.6 nm and 60 images of the 375 n…
Volcanic flows versus water- and ice-related outburst deposits in eastern Hellas: A comparison
Jaumann, R.; Stephan, K.; Hauber, E. +1 more
Hellas Planitia is one of the major topographic sinks on Mars for the deposition of any kind of sediments. We report on our observations of sheet deposits in the eastern part of the basin that are apparently related to the Dao Vallis outflow channel. The deposits have lobate flow fronts and a thickness of a few decameters. Despite their generally …
Dust Impact Monitor (SESAME-DIM) on-board Rosetta/Philae: Aerogel as comet analog material
Flandes, Alberto; Krüger, Harald; Loose, Alexander +8 more
On 12 November 2014, during the descent of the Rosetta lander Philae to the surface of comet 67P/Churyumov-Gerasimenko the Dust Impact Monitor (DIM) on board Philae recorded an impact of a cometary dust impact of a cometary dust particle at 2.4 km from the comet surface (5 km from the nucleus' barycentre). In this work, we report further experimen…
PFS/MEX limb observations of 4.3-µm CO2 non-LTE emission in the atmosphere of Mars
Sindoni, G.; Formisano, V.; Longobardo, A. +3 more
We present PFS-MEX limb observations of the CO2 non-local thermodynamic equilibrium (non-LTE) emission at 4.3 µm in the atmosphere of Mars collected in more than six Martian years. With unprecedented spatial and temporal coverage, and relatively high spectral resolution, this unique dataset promises to improve our understanding of…