Rev 168 - June 17th-July 10th 2012 - Titan at distance, And non -targeted Tethys Options

[jasedm]

Latest article is available
In summary, some distant Titan studies, more astrometric observations of smaller inner moons, and obs of the F-ring, and A-ring 'propellers'
There's a day-and-a-half stare at 'Ymir' for light-curve data, and a non-targeted Tethys encounter at ~68,000km. This should reveal Odysseus, and the northern hemisphere in some detail - closest approach images should resemble this:

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[ngunn]

You've done a fantastic job with this and, amazingly, no-one else has had a go, so thanks a million! Can you esimate the speed or period of rotation of the cloud from that?

I suppose it's not a total surprise that a circular weather feature is rotating, but a timescale would add a lot of information.

Next questions: Is it a cyclone or an anticyclone? The atmospheric pressure at this level is very low (-1mb) so quite a subtle energy source could be responsible. Is there radiative heating from methane condensation in the troposphere that passes right through the stratosphere before causing convection and condensation in the mesosphere? Alternatively does heating in the troposphere heft the whole stratosphere and mesosphere upward producing the same result? It comes down to this: are the (presumably ethane) mesospheric clouds cumuliform or stratiform? I don't think we have the resolution to determine that from the images alone but maybe the scientists will pull the evidence together.

Titan appears to have two weather systems one on top of the other, and going a very long way up.