Search Publications
Composition of Surface Materials on the Moons of Mars
Thomas, Nicolas; Pieters, Carle M.; Murchie, Scott +1 more
The two small asteroid-like bodies orbiting Mars, Phobos and Deimos, are low albedo and exhibit similar visible to near-infrared spectra. Determining the origin of these moons is closely tied to determining their composition. From available spectroscopic data Phobos exhibits two distinct types of materials across its surface, and data from both Ma…
Mapping the wavelength position of deepest absorption features to explore mineral diversity in hyperspectral images
van Ruitenbeek, Frank J. A.; Bakker, Wim H.; van der Werff, Harald M. A. +5 more
A new method is presented for the exploratory analysis of hyperspectral OMEGA imagery of Mars. It involves mapping the wavelength position and depth of the deepest absorption feature in the range between 2.1 and 2.4 µm, where reflectance spectra of minerals such as phyllosilicates, carbonates and sulphates contain diagnostic absorption featu…
A cold hydrological system in Gale crater, Mars
McKay, Christopher P.; Squyres, Steven W.; Clifford, Stephen M. +9 more
Gale crater is a ~154-km-diameter impact crater formed during the Late Noachian/Early Hesperian at the dichotomy boundary on Mars. Here we describe potential evidence for ancient glacial, periglacial and fluvial (including glacio-fluvial) activity within Gale crater, and the former presence of ground ice and lakes. Our interpretations are derived …
The age of Phobos and its largest crater, Stickney
Neukum, G.; Michael, G. G.; Murray, J. B. +2 more
We derived crater production functions and chronology functions of Phobos for two scenarios, which likely represent the end-members of its dynamical evolution. Case A assumes that Phobos has been in its current orbit about Mars since its formation. Case B assumes a recent capture of Phobos and the impact history of an average Main Belt Asteroid. W…
Drainage systems of Lonar Crater, India: Contributions to Lonar Lake hydrology and crater degradation
Sekine, Yasuhito; Matsui, Takafumi; Komatsu, Goro +3 more
Lonar, a 1.8-km-diameter impact crater in India, is a rare example of terrestrial impact craters formed in basaltic bedrock. The estimated age of the crater ranges widely from less than 12 ka to over 600 ka, but the crater preserves a relatively pristine morphology. We conducted a study of various drainage systems of Lonar Crater. The crater floor…
Spectroscopy and detectability of liquid brines on mars
Pommerol, A.; Schmitt, B.; Massé, M. +5 more
Recent geomorphological observations as well as chemical and thermodynamic studies demonstrate that liquid water should be stable today on the Martian surface at some times of the day. In Martian conditions, brines would be particularly more stable than pure water because salts can depress the freezing point and lower the evaporation rate of water…
The variable extension of Saturn's electron radiation belts
Krupp, N.; Roussos, E.; Krimigis, S. M. +4 more
Contrary to the permanent MeV ion belts which are relatively stable in intensity over both short and long time scales and are modulated by a single Galactic Cosmic Ray driven source, the electron belts of Saturn appear to be much more complex in both structure and temporal evolution. In order to understand the responses of this system to the diffe…
Floor-Fractured Craters on Mars - Observations and Origin
Jaumann, R.; Michael, G. G.; Kneissl, T. +2 more
Floor-Fractured Craters (FFCs) represent an impact crater type, where the infilling is separated by cracks into knobs of different sizes and shapes. This work focuses on the possible processes which form FFCs to understand the relationship between location and geological environment. We generated a global distribution map using new High Resolution…
A non-monotonic eddy diffusivity profile of Titan's atmosphere revealed by Cassini observations
Kammer, Joshua A.; Zhang, Xi; Li, Cheng +3 more
Recent measurements from the limb-view soundings of Cassini/CIRS and the stellar occultations from Cassini/UVIS revealed the complete vertical profiles of minor species (e.g., C2H2 and C2H4) from 100 to 1000 km in the atmosphere of Titan. In this study, we developed an inversion technique to retrieve the…
Geometry, stratigraphy and evidences for fluid expulsion within Crommelin crater deposits, Arabia Terra, Mars
Rossi, A. P.; Pondrelli, M.; Franchi, F. +1 more
Conical mounds and furrows are widely interpreted as the morphological evidences of fluids expulsion on the martian surface. In the Crommelin crater (equatorial Arabia Terra) furrows and conical mounds are exhumed within light-toned equatorial layered deposits (ELDs). Aim of this paper is to describe these landforms and discuss their potential rel…