Search Publications

Large Abundances of Polycyclic Aromatic Hydrocarbons in Titan's Upper Atmosphere

López-Puertas, M.; D'Aversa, E.; García-Comas, M. +6 more

In this paper, we analyze the strong unidentified emission near 3.28 µm in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 µm…

Detection of Propene in Titan's Stratosphere

Irwin, P. G. J.; Teanby, N. A.; Flasar, F. M. +9 more

The Voyager 1 flyby of Titan in 1980 gave a first glimpse of the chemical complexity of Titan's atmosphere, detecting many new molecules with the infrared interferometer spectrometer (IRIS). These included propane (C₃H₈) and propyne (CH₃C₂H), while the intermediate-sized C₃H _x hydr…

The Radial Distribution of Water Ice and Chromophores across Saturn's System

Brown, R. H.; Buratti, B. J.; Clark, R. N. +11 more

Over the past eight years, the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini orbiter has returned hyperspectral images in the 0.35-5.1 µm range of the icy satellites and rings of Saturn. These very different objects show significant variations in surface composition, roughness, and regolith grain size as a result of th…

A Transmission Spectrum of Titan's North Polar Atmosphere from a Specular Reflection of the Sun

Nicholson, Philip D.; Sotin, Christophe; Barnes, Jason W. +9 more

Cassini/VIMS T85 observations of a solar specular reflection off of Kivu Lacus (87.°4N 241.°1E) provide an empirical transmission spectrum of Titan's atmosphere. Because this observation was acquired from short range (33,000 km), its intensity makes it visible within the 2.0, 2.7, and 2.8 µm atmospheric windows in addition to the 5 µm …

Erratum: "An Estimate of the Chemical Composition of Titan's Lakes" (2009, ApJL, 707, L128)

Mousis, Olivier; Lunine, Jonathan I.; Lavvas, Panayotis +2 more

Solar Occultation by Titan Measured by Cassini/UVIS

Koskinen, Tommi T.; Yelle, Roger V.; McClintock, William E. +4 more

We present the first published analysis of a solar occultation by Titan's atmosphere measured by the Ultraviolet Imaging Spectrograph on board Cassini. The data were measured during flyby T53 in 2009 April and correspond to latitudes between 21° and 28° south. The analysis utilizes the absorption of two solar emission lines (584 Å and 630 Å) in th…

Distribution of CO₂ in Saturn's Atmosphere from Cassini/cirs Infrared Observations

Flasar, F. M.; Achterberg, R. K.; Jennings, D. E. +9 more

This paper focuses on the CO₂ distribution in Saturn's atmosphere based on analysis of infrared spectral observations of Saturn made by the Composite Infrared Spectrometer aboard the Cassini spacecraft. The Cassini spacecraft was launched in 1997 October, inserted in Saturn's orbit in 2004 July, and has been successfully making infrared…

Vertical Relaxation of a Moonlet Propeller in Saturn's A Ring

Seiß, M.; Spahn, F.; Hoffmann, H.

Two images, taken by the Cassini spacecraft near Saturn's equinox in 2009 August, show the Earhart propeller casting a 350 km long shadow, offering the opportunity to watch how the ring height, excited by the propeller moonlet, relaxes to an equilibrium state. From the shape of the shadow cast and a model of the azimuthal propeller height relaxati…