Search Publications
Low velocity collisions of porous planetesimals in the early solar system
Kührt, E.; Davidsson, B.; Hviid, S. +1 more
The ESA Rosetta mission has shown that Comet 67P/Churuymov-Gerasimenko is bi-lobed, has a high average porosity of around 70%, does not have internal cavities on size scales larger than 10 m, the lobes could have individual sets of onion shell-like layering, and the nucleus surface contains 100 m-scale cylindrical pits. It is currently debated whe…
Ejecta deposits of Bakhuysen Crater, Mars
Tornabene, L. L.; Osinski, G. R.; Caudill, C. M.
Bakhuysen Crater is a Late Noachian to Early Hesperian age ∼150 km-diameter impact structure located in the heavily cratered southern highlands of Mars. It is one of the largest craters on Mars with well-preserved ejecta deposits. Impact ejecta deposits allow an understanding of crustal composition, volatile content, and evolution of terrestrial p…
Retrieval of H2O abundance in Titan's stratosphere: A (re)analysis of CIRS/Cassini and PACS/Herschel observations
Lellouch, E.; Irwin, P. G. J.; Teanby, N. A. +6 more
Since its first measurement 20 years ago by the Infrared Space Observatory (ISO), the water (H2O) mole fraction in Titan's stratosphere remains uncertain due to large differences between the determinations from available measurements. More particularly, the recent measurements made from the Herschel observatory (PACS and HIFI) estimated…
Internal gravity, self-energy, and disruption of comets and asteroids
Korycansky, D. G.; Dobrovolskis, Anthony R.
The internal gravity and self-gravitational energy of a comet, asteroid, or small moon have applications to their geophysics, including their formation, evolution, cratering, and disruption, the stresses and strains inside such objects, sample return, eventual asteroid mining, and planetary defense strategies for potentially hazardous objects. Thi…
The strength of ice-saturated extraterrestrial rock analogs
Seager, Sara; Atkinson, Jared; Durham, William B.
In situ resource utilization (ISRU) activities have been identified by the National Research Council as one of the most important scientific endeavors of the coming decade. The failure of the MUPUS-PEN experiment on Rosetta's Philae lander to penetrate the surface of comet 67P demands knowledge of the mechanical properties of extraterrestrial mate…
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. …