First decent views of the surface of Titan


In case you’ve been living in a box somewhere, the NASA/ESA spacecraft Cassini-Huygens successfully fired its rockets on July 1, slowing down enough to be captured by Saturn’s gravity and enter a highly elliptical orbit around Saturn. If the rocket burn had failed, Saturn’s gravity boost would have given Cassini enough velocity to escape the solar system, so this was a fairly important part of the 7-year mission.

Cassini threaded a gap in the rings (twice), flew within one Saturn-diameter of Saturn, and took some ultra-close snapshots of Saturn’s rings. Soon afterwards, Cassini made a moderately close Titan flyby, getting the first decent images of the surface of the solar system’s second-biggest moon.

Clicking these thumbnails will take you to the full resolution version on the NASA website.

As you can see (left), in the wavelengths of visible light (400-700 nanometers), Titan appears covered in impenetrable red haze. However, by using longer infrared wavelengths (2000, 2800, and 5000 nanometers), the Cassini cameras can peer through the haze.

The central image is a false-color composite of images taken at these longer wavelengths (right).

No one website seems to have all of the new images in one place. Below are the ones that I have found to be useful.

* Latest press images * Latest raw images * NASA Flash site on Cassini Mission * More processed images at * A pretty spiffy Quicktime movie of Cassini’s rings encounter * Cassini’s current position


Any conjectures on what Huygens will find next year?

Hydrocarbon oceans, I bet. Based on the images it’s clear there is a lot of variability on the surface, but the environment is so alien I am not confident making any guesses about what any of the features are. Lucky for us, Cassini has radar on top of everything else, so we’ll get at least a partial map of the surface eventually.

These images are just a small taste of what is coming. The Cassini orbiter will have for close encounters with Titan including one at only 500 km. Obviously the Huygens, if all goes well, will give us some images from much closer and possibly the surface itself. And as Nick pointed in the above comment, Cassini has a radar.

– Anti-spam: replace “usenet” with “harlequin2”

The hydrocarbon-ocean hypothesis has actually gotten much less likely after the flyby: that blocky-looking image is from Cassini’s mapping spectrograph, and it revealed that the dark areas have less organic material in them than the light areas, and may just be regions covered with water ice. And the light areas probably aren’t liquid, since there are dark linear markings that look like fissures in them. They might be continents of waxy material over the top of solid ice. But I doubt that anyone will be sure of much until the next flyby in October.

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This page contains a single entry by Nick Matzke published on July 3, 2004 5:27 PM.

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