Search Publications
The stratigraphy of the Amenthes region, Mars: Time limits for the formation of fluvial, volcanic and tectonic landforms
Hiesinger, H.; Ivanov, M. A.; Erkeling, G. +2 more
We present results of our morphologic and stratigraphic investigations in the Amenthes region for which our observations suggest a complex spatial and temporal interrelation between volcanic and possibly water-related processes. We have produced a series of self-consistent geological maps and a stratigraphic correlation chart that show the spatial…
A multilayer model for thermal infrared emission of Saturn's rings. III: Thermal inertia inferred from Cassini CIRS
Spilker, Linda; Ohtsuki, Keiji; Morishima, Ryuji
The thermal inertia values of Saturn's main rings (the A, B, and C rings and the Cassini division) are derived by applying our thermal model to azimuthally scanned spectra taken by the Cassini Composite Infrared Spectrometer (CIRS). Model fits show the thermal inertia of ring particles to be 16, 13, 20, and 11 J m -2 K -1 s <…
Morphology and variability of the Titan ringlet and Huygens ringlet edges
Colwell, Joshua E.; Esposito, Larry W.; Jerousek, Richard G.
We present a forward modeling approach for determining, in part, the ring particle spatial distribution in the vicinity of sharp ring or ringlet edges. Synthetic edge occultation profiles are computed based on a two-parameter particle spatial distribution model. One parameter, h, characterizes the vertical extent of the ring and the other, δ, char…
Deep Impact, Stardust-NExT and the behavior of Comet 9P/Tempel 1 from 1997 to 2010
A'Hearn, M. F.; Vincent, J. -B.; Bhatt, B. C. +55 more
We present observational data for Comet 9P/Tempel 1 taken from 1997 through 2010 in an international collaboration in support of the Deep Impact and Stardust-NExT missions. The data were obtained to characterize the nucleus prior to the Deep Impact 2005 encounter, and to enable us to understand the rotation state in order to make a time of arrival…
Non-LTE radiative transfer for sub-millimeter water lines in Comet 67P/Churyumov-Gerasimenko
Kamp, Lucas; Gulkis, Samuel; Lee, Seungwon +2 more
The European Space Agency (ESA) Rosetta spacecraft (Schulz, R., Alexander, C., Boehnhardt, H., Glassmeier, K.H. (Eds.) [2009]. "ROSETTA - ESA") will encounter Comet 67P/Churyumov-Gerasimenko in 2014 and spend the next 18 months in the vicinity of the comet, permitting very high spatial and spectral resolution observations of the coma and nucleus. …
Scattering particles in nightside limb observations of Venus’ upper atmosphere by Venus Express VIRTIS
Irwin, P. G. J.; Drossart, P.; Piccioni, G. +2 more
Nightside infrared limb spectra of the Venus upper atmosphere, obtained by Venus Express VIRTIS, show strong scattering of thermal radiation. This scattering of upward-going radiation into the line-of-sight is dominant below 82.5 km even at a wavelength of 5 µm, which is indicative of relatively large particles. We show that 1 µm-sized…
Improved measurement of Asteroid (4) Vesta’s rotational axis orientation
Russell, Christopher T.; Thomas, Peter C.; Li, Jian-Yang +6 more
We report an improved measurement of the rotational axis orientation of Asteroid (4) Vesta. By analyzing and combining all previous measurements using a limb-fitting technique from ground/HST data collected from 1983 to 2006, we derive a pole solution of (RA = 304.5°, Dec = 41.5°). Images of Vesta acquired with the Wide Field Camera 3 onboard the …
Jovian chromophore characteristics from multispectral HST images
Simon-Miller, Amy A.; Chanover, Nancy J.; Strycker, Paul D. +2 more
The chromophores responsible for coloring the jovian atmosphere are embedded within Jupiter's vertical aerosol structure. Sunlight propagates through this vertical distribution of aerosol particles, whose colors are defined by ϖ0( λ), and we remotely observe the culmination of the radiative transfer as I/ F( λ). In this study, we employ…
Chaos formation by sublimation of volatile-rich substrate: Evidence from Galaxias Chaos, Mars
Head, J. W.; Pedersen, G. B. M.
Galaxias Chaos deviates significantly from other chaotic regions due to the lack of associated outflow channels, lack of big elevation differences between the chaos and the surrounding terrain and due to gradual trough formation. A sequence of troughs in different stages is observed, and examples of closed troughs within blocks suggest that the tr…
An assessment and test of Enceladus as an important source of Saturn’s ring atmosphere and ionosphere
Ip, Wing-Huen; Tseng, Wei-Ling
The existence of an oxygen exosphere and ionosphere in Saturn’s main ring region has been confirmed by the Saturn Orbital Insertion (SOI) observations of the Cassini spacecraft. Through the ion-molecule collisions, the ring atmosphere could serve as a source of O2+ ions throughout Saturn’s magnetosphere. If photolysis of ice in the main rings is t…