Search Publications
Analysis of Cassini/CIRS limb spectra of Titan acquired during the nominal mission II: Aerosol extinction profiles in the 600-1420 cm -1 spectral range
Bézard, Bruno; Vinatier, Sandrine; Nixon, Conor A. +10 more
We have analyzed the continuum emission of limb spectra acquired by the Cassini/CIRS infrared spectrometer in order to derive information on haze extinction in the 3-0.02 mbar range (∼150-350 km). We focused on the 600-1420 cm -1 spectral range and studied nine different limb observations acquired during the Cassini nominal mission at 5…
Disk-integrated bolometric Bond albedos and rotational light curves of saturnian satellites from Cassini Visual and Infrared Mapping Spectrometer
Buratti, Bonnie J.; Mosher, Joel A.; Pitman, Karly M.
We present values from the Cassini Visual and Infrared Mapping Spectrometer (VIMS) of four fundamental disk-integrated spectrophotometric properties (bolometric Bond albedo, solar phase curve, phase integral, and geometric albedo at 7-15 different wavelengths in the λ = 0.35-5.1 µm range) for five mid-sized saturnian icy satellites: Rhea, Di…
Radarclinometry of the sand seas of Africa’s Namibia and Saturn’s moon Titan
Kirk, Randolph L.; Lorenz, Ralph D.; Neish, Catherine D. +1 more
Radarclinometry is a powerful technique for estimating heights of landforms in synthetic aperture radar (SAR) images of planetary surfaces. In particular, it has been used to estimate heights of dunes in the sand seas of Saturn's moon Titan (Lorenz, R.D., and 39 colleagues [2006]. Science 312, 724-727). In this work, we verify the technique by com…
(47171) 1999 TC 36, A transneptunian triple
Grundy, W. M.; Noll, K. S.; Benecchi, S. D. +1 more
We present new analysis of HST images of (47171) 1999 TC 36 that confirm it as a triple system. Fits to the point-spread function (PSF) consistently show that the apparent primary is itself composed of two similar-sized components. The two central components, A1 and A2, can be consistently identified in each of nine epochs spread over 7…
The structure and time variability of the ring atmosphere and ionosphere
Johnson, R. E.; Ip, W. -H.; Elrod, M. K. +2 more
The saturnian system is subject to constant bombardment by interplanetary meteoroids and irradiation by solar UV photons. Both effects release neutral molecules from the icy ring particles either in the form of impact water vapor or gas emission in the form of H 2O, O 2 and H 2. The observations of the Cassini spac…
Gully formation on Mars: Two recent phases of formation suggested by links between morphology, slope orientation and insolation history
Head, James W.; Forget, François; Spiga, Aymeric +2 more
The unusual 80 km diameter Noachian-aged Asimov crater in Noachis Terra (46°S, 5°E) is characterized by extensive Noachian-Hesperian crater fill and a younger superposed annulus of valleys encircling the margins of the crater floor. These valleys provide an opportunity to study the relationships of gully geomorphology as a function of changing slo…
Estimation of the escape of photoelectrons from Mars in 2004 liberated by the ionization of carbon dioxide and atomic oxygen
Coates, A. J.; Fedorov, A.; Barabash, S. +8 more
Photoelectron peaks in the atmosphere of Mars caused by the ionization of carbon dioxide and atomic oxygen by solar 30.4 nm photons have been observed by the Electron Spectrometer (ELS), a component of the Mars Express (MEx) Analyzer of Space Plasmas and Energetic Atoms (ASPERA-3) experiment. Ionization mostly occurs at the Mars exobase with the m…
A Late Amazonian alteration layer related to local volcanism on Mars
Mangold, N.; Le Mouélic, S.; Mustard, J. F. +7 more
Hydrated minerals on Mars are most commonly found in ancient terrains dating to the first billion years of the planet's evolution. Here we discuss the identification of a hydrated light-toned rock unit present in one Chasma of the Noctis Labyrinthus region. Stratigraphy and topography show that this alteration layer is part of a thin unit that dra…
Particle size and abundance of HC3N ice in Titan’s lower stratosphere at high northern latitudes
Achterberg, R. K.; Anderson, C. M.; Samuelson, R. E. +1 more
Up to now, there has been no corroboration from Cassini CIRS of the Voyager IRIS-discovery of cyanoacetylene (HC 3N) ice in Titan's thermal infrared spectrum. We report the first compelling spectral evidence from CIRS for the ν6 HC 3N ice feature at 506 cm -1 at latitudes 62°N and 70°N, from which we der…
A 3 km atmospheric boundary layer on Titan indicated by dune spacing and Huygens data
Lorenz, Ralph D.; Radebaugh, Jani; Tokano, Tetsuya +2 more
Some 20% of Titan's surface is covered in large linear dunes that resemble in morphology, size and spacing (1-3 km) those seen on Earth. Although gravity, atmospheric density and sand composition are very different on these two worlds, this coincident size scale suggests that the controlling parameter limiting the growth of giant dunes, namely the…