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Full Version: Rev 168 - June 17th-July 10th 2012 - Titan at distance
Unmanned Spaceflight.com > Outer Solar System > Saturn > Cassini Huygens > Cassini's ongoing mission and raw images
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:
ugordan
Rough Saturn color view utilizing a wide-angle CB2 frame and a BL1 frame at 1/4 resolution:

Click to view attachment
toddbronco2
Wow, it looks like there's something interesting going on with this cloud on Titan. Is this a circular cloud around the pole or something?
http://saturn.jpl.nasa.gov/multimedia/imag...4/N00191673.jpg
nprev
Don't think that's one of the polar regions, but I could be wrong.

VERY interesting.

Also visible in a wide-angle view:

http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=264892
toddbronco2
I was surprised that there wasn't already a conversation about this going on. The scientists doing the Titan cloud monitoring will love this. No wonder they plan so many of these observations.

ADMIN EDIT: There has been some mention of it here.
ngunn
Titan's very own noctilucent clouds! Once again, Earth is not alone.

EDIT Here's the terrestrial version seen from space for comparison: http://cdn.physorg.com/newman/gfx/news/hir...ysteriousno.jpg
Bjorn Jonsson
This feature contains some very interesting detailed structure that I'm sure is not due to JPG artifacts. A cropped and enhanced version of the image toddbronco2 mentioned:

Click to view attachment
Hungry4info
These concentric circular features are incredible.
Hungry4info
Oh goodness it spins.

(animation)

Edit: It seems the programme I use to make gifs is putting some abhorrent artefacts into the animation. Hopefully someone can get a better one.
Phil Stooke
Gifs don't like smooth gradients like these, especially if the bits/pixel are reduced.

Phil
elakdawalla
Oh man....I have so many more things to do today.....may not be able to resist shoving it all aside to play with spinny Titan clouds.....
Hungry4info
Taking what Phil said into consideration, I increased the contrast a bit until I was satisfied.

(animation)
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.
Hungry4info
Thanks.
QUOTE (ngunn @ Jul 1 2012, 04:45 PM) *
Can you esimate the speed or period of rotation of the cloud from that?
Unfortunately not. I have no idea when exactly the images were taken.

Edit: The observability of the rotation behaviour is not new. Here it is seen on Jun 8 with Titan nearly at a full phase.

(animation)
jasedm
Wow - that is quite something! and pretty unexpected too I would imagine - nice processing Hungry4info.

BTW, Tethys encounter raws are up
Ian R
Here's my version of the polar cap movie:

http://youtu.be/6Z3_029xlxw?hd=1
ngunn
Good! It looks from both versions that there might be some smaller circulatory features at the edges of the main one. Can we telll for sure from the direction of rotation whether it's cyclonic or anticyclonic?
Bjorn Jonsson
There has been a lot of interesting ring images recently, e.g. this one of the F ring: http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=264947
elakdawalla
There have been a *ton* of cool images recently. I'd love to animate some of those rings images. It'll have to wait til after my vacation! And there should be a new Cassini PDS release out, right?
Astro0
> jasedm: BTW, Tethys encounter raws are up

Nice smile.gif

Click to view attachment
charborob
I tried animating a series of images of the rings (raw frames number N00191994 to N00192059):
Click to view attachment
Bjorn Jonsson
Looks great and makes it obvious just how variable the location of the outer edge of the B ring is.
jasedm
AstroO - that's a beaut! - I'm going to have to train myself on photoshop!
Ian R
Did this quickly on my laptop while watching Criminal Minds, so the color may not be very good . . .

Click to view attachment
Ian R
A big 'wow' and 'sweet' to Astro and charborob (this forum needs a 'Like' button).
Bjorn Jonsson
Here is an animation showing the F ring.:

Click to view attachment

This is composed from images N00191724.jpg to N00191763.jpg (40 frames) and is encoded using the Xvid codec. The images were obtained on June 27, 2012 at a range of ~750,000 km. The frame rate is 8 frames/second so this looks a bit jerky. I therefore made an experimental version by 'tweening' the animation using the MSU frame rate conversion filter but it didn't work well for parts of the animation although other parts are better. Here is the tweened version:

Click to view attachment
Astro0
QUOTE (elakdawalla @ Jul 3 2012, 03:36 PM) *
There have been a *ton* of cool images recently. I'd love to animate some of those rings images. ...


Your wish is my command smile.gif
http://youtu.be/T4zjYankAx0
volcanopele
Our official image advisory on the south polar vortex is now up:

http://www.ciclops.org/view.php?id=7239

We've released an RGB color image of the stratospheric cloud taken on June 26 as well a blue filter movie.

Color image
http://www.ciclops.org/view/7235/Titans_Co...th_Polar_Vortex

BL1 filter movie
http://www.ciclops.org/view/7236/Titans_So...ortex_in_Motion

There are also a pair of images taken by VIMS during the two recent flybys of this feature. While not included in this image advisory, ISS has observed this stratospheric cloud since at least March 27 (I should point out that we have seen the area for a longer period of time, albeit at the limb, but it isn't like feature just turned on over night. March 27 is just the earliest I can say that yep, the stratospheric cloud was there]
http://www.ciclops.org/view/7237/Winters_Coming
(yes someone on the VIMS is a Game of Thrones fan...clearly)

The movie covers a period of nine hours, with each frame separated by one hour (so that gives you a rotation period of about 8 hours, so some pretty fast winds at high altitude)
volcanopele
For those curious about how big this Titan south polar vortex thing is, it's about 575x784 km (360x490 mi) in size.
nprev
Beautiful images and a fascinating find!!! Great work, Jason!
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