Search Publications
Sizes of main-belt asteroids by combining shape models and Keck adaptive optics observations
Hanuš, J.; Marchis, F.; Ďurech, J.
We select 50 main-belt asteroids with a diameter between 20 and 400 km for which we have (i) shape models derived by the lightcurve inversion method and (ii) resolved observations of good quality collected with the Keck II adaptive optics (AO) system in the near-infrared. We derive the size of these asteroids by minimizing the difference between t…
NeMars: An empirical model of the martian dayside ionosphere based on Mars Express MARSIS data
Sánchez-Cano, B.; Witasse, O.; Radicella, S. M. +2 more
Several models of the martian ionosphere have been developed in the last years. In this paper, a new empirical model for the dayside electron density of the martian ionosphere (primary and secondary layer), called NeMars, is described. The model is mainly based on MARSIS AIS data (Active Ionospheric Sounding from the Mars Advanced Radar and Ionosp…
Morphology of fluvial networks on Titan: Evidence for structural control
Black, Benjamin A.; Perron, J. Taylor; Burr, Devon M. +2 more
Although Titan’s surface shows clear evidence of erosional modification, such as fluvial incision, evidence for tectonism has been less apparent. On Earth, fluvial networks with strongly preferred orientations are often associated with structural features, such as faults or joints, that influence flow or erodibility. We delineated and classified t…
Mars ionosphere total electron content analysis from MARSIS subsurface data
Amata, E.; Orosei, R.; Picardi, G. +6 more
We describe a method to estimate the total electron content (TEC) of the Mars ionosphere from the output parameters of an algorithm, called the Contrast Method (Picardi, G., Sorge, S. [2000]. Proc. SPIE. Eighth International Conference on Ground Penetrating Radar, vol. 4084, pp. 624-629; Ilyushin, Ya.A., Kunitsyn, V.E. [2004]. J. Commun. Technol. …
Connections between spectra and structure in Saturn’s main rings based on Cassini VIMS data
Clark, R. N.; Nicholson, P. D.; Hedman, M. M. +4 more
Saturn’s main rings exhibit variations in both their opacity and their spectral properties on a broad range of spatial scales, and the correlations between these parameters can provide insights into the processes that shape the composition and dynamics of the rings. The Visual and Infrared Mapping Spectrometer (VIMS) instrument onboard the Cassini…
Saturn’s Great Storm of 2010-2011: Evidence for ammonia and water ices from analysis of VIMS spectra
Baines, K. H.; Sromovsky, L. A.; Fry, P. M.
Our analysis of Cassini/VIMS near-infrared spectra of Saturn’s Great Storm of 2010-2011 reveals a multi-component aerosol composition comprised primarily of ammonia ice, with a significant component of water ice. The most likely third component is ammonium hydrosulfide or some weakly absorbing material similar to what dominates visible clouds outs…
Near-infrared spectral monitoring of Pluto's ices: Spatial distribution and secular evolution
Olkin, C. B.; Buie, M. W.; Young, E. F. +2 more
We report results from monitoring Pluto's 0.8 to 2.4 µm reflectance spectrum with IRTF/SpeX on 65 nights over the dozen years from 2001 to 2012. The spectra show vibrational absorption features of simple molecules CH4, CO, and N2 condensed as ices on Pluto's surface. These absorptions are modulated by the planet's 6.39 …
Observations of D/H ratios in H2O, HCl, and HF on Venus and new DCl and DF line strengths
Li, G.; Belyaev, D. A.; Krasnopolsky, V. A. +2 more
Intensities of the spectral lines in the fundamental bands of D35Cl and DF were calculated using the semi-empirical dipole moment functions derived from the most accurate and precise measurements of intensities of the ro-vibrational lines of H35Cl and HF. Values obtained in this way for the deuterated species are superior to …
Multiple working hypotheses for the formation of compositional stratigraphy on Mars: Insights from the Mawrth Vallis region
Baldridge, A. M.; Michalski, Joseph R.; Cuadros, J. +1 more
A unique aspect of martian geology is the presence of similar compositional stratigraphy observed in many locations throughout the surface. Where the Al-rich and Fe/Mg-rich clay minerals occur together, aluminous clays typically overly layered ferromagnesian clays, possibly indicating that precipitation-driven leaching occurred in a warmer, wetter…
Evidence for two modes of water release in Comet 103P/Hartley 2: Distributions of column density, rotational temperature, and ortho-para ratio
Villanueva, Geronimo L.; Mumma, Michael J.; Meech, Karen J. +5 more
This paper presents long-slit spectra of H2O emission from the inner coma of Comet 103P/Hartley 2, acquired with NIRSPEC/Keck 2 during the comet's close approach to Earth in 2010. On UT 19.6 October 2010 the slit was oriented nearly orthogonal to the projected (in the plane of the sky) Sun-comet line, and the H2O rotational t…