An update on findings from Cassini's latest flyby of Saturn's largest moon, Titan.


Hi. I'm Candice Hansen. I'm the Titan discipline scientist for Cassini. The Cassini spacecraft has been touring the Saturn system since July 2004. I'm reporting today on our latest flyby of Titan, Saturn's largest moon.

On September 7, we made our most recent flyby of Titan. The spacecraft altitude above the surface was just 1000 kilometers, or 620 miles.

Titan has a geologically young surface. Old surfaces have lots of craters. On our last flyby we found just the third crater on Titan so far, by using Cassini's radar to penetrate through the hazy atmosphere.

On Earth, craters have been erased by volcanoes, plate tectonics and erosion. We are just beginning to figure out what is modifying Titan's surface. We know wind plays a big role. Cassini has discovered dunes across a large portion of Titan's surface. In the latest radar data we also see more dunes. Each radar swatch covers about 1-percent of the surface of Titan.

We also compare Titan's atmosphere to that of the Earth. Both are composed primarily of nitrogen. But on Titan, instead of oxygen, the minor constituent is methane. Methane decomposes and forms smog that obscures the surface except at long wavelengths of light. We use Cassini's near infrared spectrometer to see through the haze.

Back in July, we detected a bright cloud in the atmosphere. This may be a source of the methane rain that we know has carved river channels on Titan's surface.

Our next close flyby of Titan will be on September 23. Our altitude above the surface will be just 960 kilometers, or 600 miles. This is one of our closest flybys. Our main scientific emphasis will be to study the very highest part of Titan's atmosphere.

I'm Candice Hansen. I'll be back in a few weeks with a report on that Titan flyby and more on the Cassini mission to Saturn.
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