Investigating the Composition of Saturn's Rings Using Cassini CIRS Data
Abstract
Although it has long been known that Saturn's rings are primarily composed of water ice, the identities of the trace constituents-- which provide subtle color to the rings and could shed light on their origin and formation-- remain poorly understood. These trace constituents may affect the thermal infrared part of the rings' spectral signature. Previous observations have not observed any such effects. However, they have been hindered by one or more major problems: 1) the inability to observe the entire wavelength interval through the earth's atmosphere, 2) low spectral resolution, and 3) limited range of geometries. Data obtained with Cassini's Composite Infrared Spectrometer (CIRS) instrument circumvents these difficulties. We report results from a preliminary investigation of ring composition using CIRS data over the wavelength range of 10 to 600 cm-1. The rings spectra observed by CIRS are a complicated combination of thermal emissions, the effects of scattering from ring particles (broad size distribution) and noise. Before the signal can be examined for the faint absorption features from contaminants, the contributions of scattering and thermal emission must be accounted for and removed using Mie scattering and standard radiation transfer techniques. We present the initial results of this investigation. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, and was sponsored by the Space Grant program.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.P43B1293N
- Keywords:
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- 5759 Rings and dust;
- 6020 Ices;
- 6265 Planetary rings