Search Publications
Particle sizes in Saturn's rings from UVIS stellar occultations 1. Variations with ring region
Colwell, J. E.; Cooney, J. H.; Esposito, L. W.
The Cassini spacecraft's Ultraviolet Imaging Spectrograph (UVIS) includes a high speed photometer (HSP) that has observed stellar occultations by Saturn's rings with a radial resolution of ∼10 m. In the absence of intervening ring material, the time series of measurements by the HSP is described by Poisson statistics in which the variance equals t…
Constraints on water vapor and sulfur dioxide at Ceres: Exploiting the sensitivity of the Hubble Space Telescope
Roth, Lorenz
Far-ultraviolet observations of dwarf-planet (1) Ceres were obtained on several occasions in 2015 and 2016 by the Cosmic Origins Spectrograph (COS) and the Space Telescope Imaging Spectrograph (STIS), both on board the Hubble Space Telescope (HST). We report a search for neutral gas emissions at hydrogen, oxygen and sulfur lines around Ceres from …
Models of bright storm clouds and related dark ovals in Saturn's Storm Alley as constrained by 2008 Cassini/VIMS spectra
Baines, K. H.; Sromovsky, L. A.; Fry, P. M.
A 5° latitude band on Saturn centered near planetocentric latitude 36°S is known as "Storm Alley" because it has been for several extended periods a site of frequent lightning activity and associated thunderstorms, first identified by Porco et al. (2005). The thunderstorms appeared as bright clouds at short and long continuum wavelengths, and over…
Spectral and stratigraphic mapping of hydrated minerals associated with interior layered deposits near the southern wall of Melas Chasma, Mars
Liu, Yang; Goudge, Timothy A.; Wang, Alian +1 more
Orbital remote sensing data acquired from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) onboard Mars Reconnaissance Orbiter (MRO), in conjunction with other datasets, are used to perform detailed spectral and stratigraphic analyses over a portion of south Melas Chasma, Mars. The Discrete Ordinate Radiative Transfer (DISORT) mode…
Geology of central Libya Montes, Mars: Aqueous alteration history from mineralogical and morphological mapping
Jaumann, R.; Tirsch, D.; Bishop, J. L. +3 more
We analyze the emplacement chronology and aqueous alteration history of distinctive mineral assemblages and related geomorphic units near Hashir and Bradbury impact craters located within the Libya Montes, which are part of the southern rim of the Isidis Basin on Mars. We derive our results from a spectro-morphological mapping project that combine…
The New Horizons and Hubble Space Telescope search for rings, dust, and debris in the Pluto-Charon system
Hamilton, Douglas P.; Olkin, Cathy B.; Stern, S. Alan +11 more
We conducted an extensive search for dust or debris rings in the Pluto-Charon system before, during, and after the New Horizons encounter in July 2015. Methodologies included attempting to detect features by back-scattered light during the approach to Pluto (phase angle α ∼ 15°), in situ detection of impacting particles, a search for stellar occul…
Iron distribution of the Moon observed by the Kaguya gamma-ray spectrometer: Geological implications for the South Pole-Aitken basin, the Orientale basin, and the Tycho crater
Wöhler, C.; Ohtake, M.; Berezhnoy, A. A. +5 more
In this study we describe the distribution of iron on the Moon as obtained by the Kaguya high energy resolution gamma-ray spectrometer (KGRS). We achieved for the first time the identification of iron based on the fast neutron flux obtained by the KGRS. The iron distribution obtained by KGRS is compared to that of the Lunar Prospector Gamma-Ray Sp…
Is Kasei Valles (Mars) the largest volcanic channel in the solar system?
Leverington, David W.
With a length of more than 2000 km and widths of up to several hundred kilometers, Kasei Valles is the largest outflow system on Mars. Superficially, the scabland-like character of Kasei Valles is evocative of terrestrial systems carved by catastrophic aqueous floods, and the system is widely interpreted as a product of outbursts from aquifers. Ho…
Coloring Jupiter's clouds: Radiolysis of ammonium hydrosulfide (NH4SH)
Hudson, Reggie L.; Loeffler, Mark J.
Here we present our recent studies on the color and spectral reflectance changes induced by ∼0.9 MeV proton irradiation of ammonium hydrosulfide, NH4SH, a compound predicted to be an important tropospheric cloud component of Jupiter and other giant planets. Ultraviolet-visible spectroscopy was used to observe and identify reaction produ…
On the icy edge at Louth and Korolev craters
Bapst, Jonathan; Byrne, Shane; Brown, Adrian J.
The modern climate of Mars has been well characterized from over a decade of orbiting spacecraft, in situ measurements via landers/rovers, and theoretical advances in climate modeling. Nonetheless, important questions remain unanswered, including the present-day mass balance of the north polar residual cap and its icy outliers. Exposed water-ice m…