* Astronomy

W00028136.jpg This image of Titan was taken by the Cassini spaceprobe on May 13, 2007, when it approximately 251,631 kilometres away.


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Credit: NASA/JPL/Space Science Institute

The image was taken using the CL1 and CB3 filters.

This image of Titan was taken by the Cassini spaceprobe on May 13, 2007, when it approximately 238,486 kilometres away.


Expand (132kb, 560 x 560)
Credit: NASA/JPL/Space Science Institute

The image was taken using the CL1 and CB3 filters.

This image of Titan was taken by the Cassini spaceprobe on May 13, 2007, when it approximately 158,264 kilometres away.


Expand (121kb, 560 x 560)
Credit: NASA/JPL/Space Science Institute

The image was taken using the CL1 and CB3 filters.

Scientists have long known that the lower atmosphere of Saturn's moon Titan contains organic aerosols, or tholins, formed from simple organic molecules, such as methane and nitrogen. Researchers had assumed these tholins formed at altitudes of several hundred kilometres, but new information gathered by three particle spectrometers aboard the Cassini spacecraft shows tholin formation happens in Titan's atmosphere at altitudes greater than 1,000 kilometres. The results also show tholins form differently than previously thought.
Scientists at Southwest Research Institute (SwRI), the University of Kansas, University College London and The University of Texas at San Antonio report results of the observations in the paper "The Process of Tholin Formation in Titan's Upper Atmosphere," published in the May 11 issue of Science.

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