Spectroscopic observations of the Solar System with ISO have gratified planetary scientists with a wealth of new and exciting results. These findings relate to various investigation fields including the origin of the Solar System, the photochemistry of the giant planets, and the physical and chemical state of planetary surfaces. Observations of comets have shown fluorescence from various parent molecules, yielding their production rates. High-resolution spectra of water vapor have permitted a measurement of its rotational and spin temperatures in comets Hale-Bopp and P/Hartley 2. Crystalline Mg-rich silicates were detected in these two comets. Rotational lines of HD were observed for the first time in the four giant planets, yielding reliable determinations of the D/H ratio. The 14N/15N ratio could also be measured in the upper troposphere of Jupiter. If representative of the whole body, these two isotopic measurements bear valuable information on the planetesimals in the solar nebula. Many new hydrocarbon species were detected in the giant planets, drastically improving our knowledge of the photochemistry at work in their atmospheres. Oxygen compounds (H2O and CO2) were also detected for the first time in the upper atmospheres of these planets as well as on Titan. Their presence points to exogenic sources of oxygen with micro-meteoroid ablation being a major contributor. About ten bands of SO2 ice were detected in spectra of Io, providing constraints on the physical state and horizontal distribution of this important volcanic compound on the surface. Spectra of Mars revealed the presence of a few so-far undetected mineralogical features, tentatively attributed to carbonates. All these observations are reviewed here.
ISO Beyond the Peaks: The 2nd ISO Workshop on Analytical Spectroscopy
- Pub Date:
- November 2000
- SOLAR SYSTEM;
- PLANETS AND SATELLITES;