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Posted by: jasedm Jan 21 2011, 10:24 AM

The latest article is available http://www.ciclops.org/view/6710/Rev144.

Lots to look forward to for icy moon/rocks fans (Mimas, Enceladus, Helene and Rhea)

I notice that there's a planned search for Mimas Lagrangians too, with constraints on the size of any putative co-orbitals being <50 metres if nothing's spotted in the two observations. My intuition (nothing more) is that it's unlikely anything will be found - I'd like to be wrong though...

I hope the Helene observations go as planned (closest-approach is ~28,000km) various reasons have conspired to cause the pointing to be a little off in two of the preceding obs.

Helene gets another very close flyby in June this year at ~7000km. I wonder if they'll have another crack with the 'skeet-shooting' technique during that encounter?

Jase

Posted by: charborob Jan 24 2011, 01:13 PM

Nice images a Rhea-Dione mutual event:
http://saturn.jpl.nasa.gov/photos/raw/?start=10&storedQ=2315808

Posted by: pat Jan 25 2011, 12:44 AM

The flyby is slow enough that Cassini wil be tracking Helene continuously on reaction wheels during approach, flyby and retreat -- no need to skeet shoot, which is just as well because we're not supposed to be doing it any more (too labour intensive)

Posted by: Frank Crary Jan 25 2011, 06:21 AM

Strictly speaking. a skeet shoot isn't automatically labor intensive. This is one of several sorts of observations where the Cassini project has to make a hard choice. Doing a skeet shoot without adding too much work would add wear on the reaction wheels (which is a bad idea, if we want the mission to continue until the end of the Solstice mission in 2017.) Finding a way to do a skeet shoot without adding wear on the reaction wheels is possible, but it would take quite a bit of labor on the part of the spacecraft team, and the extended mission work force can't really support that.

Posted by: jasedm Jan 25 2011, 07:03 PM

Perhaps the technique may be used sparingly for high priority targets (e.g. Enceladus) in the coming years.

Posted by: ngunn Jan 31 2011, 12:47 PM

Difficult to pick a winner from the latest dramatic sequence of Dione: http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS66/N00167591.jpg

Posted by: eoincampbell Feb 1 2011, 02:21 AM

Now THAT'S scientific, artistic splendor...Thanks for bringing it to light...(and shade)

Posted by: ElkGroveDan Feb 1 2011, 05:41 AM

Here's a rough animation gif using a bit of morphing as well as a couple of synthesized images for the three in the sequence of twelve that were missing.

I'll post a link to a better YouTube animation as soon as it is uploaded. (please bear with me as I get better at this software)

Posted by: Ian R Feb 1 2011, 03:27 PM

Helene colour composite (IR-GRN-UV):

Stacked series of shots taken through polarizing and green filters:



The brown 'swirls' are very redolent of similar features seen on Calypso, I seem to recall.

Posted by: Ian R Feb 1 2011, 04:24 PM

This enhanced IR-GRN-UV composite of Mimas clearly shows the bluish equatorial 'stain':

Posted by: john_s Feb 1 2011, 04:30 PM

http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS66/N00167787.jpg showing Herschel in profile on the limb.

John

Posted by: ngunn Feb 1 2011, 05:01 PM

Some nice Enceladus ones too: http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS66/N00167673.jpg

(Great time for a Cassini image feast. )

Posted by: Ian R Feb 1 2011, 05:35 PM

Enceladus in IR-GRN-UV colour, illuminated by both Sol-shine and Saturn-shine:

Posted by: volcanopele Feb 1 2011, 06:11 PM

I'm so happy More pictures of my favorite, small solar system body!

Great work, Ian R.

Posted by: Ian R Feb 1 2011, 06:11 PM

Mimas and the rings in IR-CLR-UV colour:

Posted by: Ian R Feb 1 2011, 06:16 PM

Thanks Jason!

Posted by: Stu Feb 1 2011, 06:16 PM

Absolutely beautiful.

Posted by: Ian R Feb 1 2011, 06:26 PM

'Ello, 'Ello, 'Ello... what do we have here then?

http://saturn.jpl.nasa.gov/photos/raw/rawimagedetails/index.cfm?imageID=232611

Is that Pan's backend hanging out of the rings?

Posted by: Stu Feb 1 2011, 07:05 PM

Ah, the romance of space exploration...

Posted by: stevesliva Feb 1 2011, 08:10 PM

And very interesting! Thanks.

Posted by: ZLD Feb 1 2011, 08:47 PM

Full Saturn night on Enceladus.
IR1-GRN-UV3 / stacked luminance

Posted by: JohnVV Feb 1 2011, 08:50 PM

? here just below the blue mouse pointer ?
[attachment=23765:maybe.png]

Posted by: ZLD Feb 1 2011, 09:17 PM

Seems like it could be Pan.


Cassini would be somewhere in the upper right quadrant at that time if so. Good find!

Posted by: volcanopele Feb 1 2011, 09:54 PM

I'm having way too much fun matching those swirls with the features seen last March:

http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS58/N00152241.jpg
http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS58/N00152245.jpg

Posted by: machi Feb 2 2011, 11:17 AM

Wonderful images Ian and ZLD!
Helene looks like if giant medusa (or alien's larvae?) is laying on it.

Posted by: ugordan Feb 2 2011, 01:01 PM

Ugh. Why did you have to say larvae? I can't get that image out of my mind now...

Posted by: Ian R Feb 4 2011, 08:28 PM

Here's a two-footprint mosaic of Enceladus from the recent flyby:

Posted by: antipode Feb 4 2011, 11:35 PM

WoW!

P

Posted by: Ian R Feb 6 2011, 10:34 PM

Here's the full, four-footprint mosaic (assembled with a fair amount of jiggery pokery):

http://flic.kr/p/9fEQHh

Posted by: ugordan Feb 6 2011, 10:41 PM

Niiice!

Posted by: ZLD Feb 6 2011, 11:09 PM

Very well done Ian! I was hoping someone might take the time to do this mosaic, thanks!

Posted by: Ian R Feb 7 2011, 02:10 AM

You're both welcome!