Titanic antarctic vortex antics

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July 11 2012 6:22 AM

Titanic antarctic vortex antics

The Cassini spacecraft has been orbiting Saturn since late 2004, and has spent most of that time more or less in the same plane as the rings and moons. That allows it to pass close to these interesting places and see them in high resolution.

But scientists and engineers recently changed that, flinging the probe into a more inclined orbit so that it can see things from a different vantage point, literally getting a new perspective on them. For example, from this tipped path, it was able to clearly see the south pole of Titan, Saturn's ginormous moon - the biggest in the soar system, bigger than the planet Mercury! And what it saw surprised everyone, and for good reason:

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death from the Skies! Follow him on Twitter.

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Isn't that weird looking? Like some kind of bacterium, or a cell. In fact, it is a cell, but not the biological kind. It's an air cell, a vortex, a spinning around the pole. Titan has a thick atmosphere (thicker than Earth's in fact) and it moves. This cell of air rotates once every 9 hours or so, far faster than Titan's own 16 day spin. Cassini took enough images to make this animation of the vortex's motion:


Things like this are seen at the poles of other words; Saturn itself has one, as does Venus. Titan also has a "hood" a haze layer over its north pole. That may be a seasonal feature, and right now winter is coming for Titan's southern hemisphere*. Perhaps this vortex plays a part in forming the polar hood, and we'll see one over the south pole soon.

That's not clear yet, but it may become so as Cassini continues to investigate this incredible system. It's been there for almost 8 years, and we've barely scratched the surface of what's going on. There's a whole lot of real estate in the Saturn system, and it changes all the time. We could use 50 Cassinis stationed there, and it still wouldn't be enough to gather up all the beauty and amazing slices of nature to be seen.

Credits: Video: NASA/JPL-Caltech/Space Science Institute; Music: "Passing Action" by Kevin MacLeod



* Hodor!




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