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Posted by: Sunspot Oct 28 2004, 02:24 PM

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=26004

Posted by: djellison Oct 28 2004, 03:46 PM

I dont know if it's me, my browser ( Firefox ), my internet connection or what - but I dont get ANY images appearing on the saturn.jpl.nasa.gov site - until I click on the actual JPG link and I see that just fine.

Awesome picture



Doug

(ps - found that it's the browser. Firefox doesnt work, IE does. BOOO NASA - BOOOOOOO )

Posted by: volcanopele Oct 28 2004, 07:23 PM

that's a great view of Odysseus. Can't wait till this evenings downlink and we get almost full frame images of Tethys.

Posted by: Bjorn Jonsson Oct 28 2004, 08:59 PM

Based on viewing geometry information I found at the PDS Rings Node I did the attached rendering which shows which areas were visible to Cassini near closest approach. Tethys' size is shown as it should be in Cassini's images.

Bjorn

Posted by: Sunspot Oct 28 2004, 09:27 PM

Im using Firefox too, in the lst few days since the Titan encounter i've had a few problems crowsing the RAW images, but I think its due to heavy traffick to the site.

The rest of the Cassini site works OK

http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=26030

Posted by: OWW Oct 28 2004, 09:53 PM

This is a very beautiful image of tethys and the rings taken on october 15th. I have a hard time understanding what it is I am seeing in this picture.

Posted by: David Oct 29 2004, 03:23 AM

Isn't it just Tethys through a gap in the rings, with the edge of Saturn at the left side, and the shadows of the rings showing up as dark lines on Saturn's surface?

Posted by: OWW Oct 29 2004, 08:02 AM

And that band to the right of Tethys? Is that also saturn?

Posted by: BruceMoomaw Oct 29 2004, 10:43 AM

By the way, has anyone noticed one eyebrow-raiser among the new AGU Fall Meeting abstracts? http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=fm04&database=%2Fdata%2Fepubs%2Fwais%2Findexes%2Ffm04%2Ffm04&maxhits=200&="P52A-08" ("Keck Near-Infrared Observations of Saturn's E and G Rings during Earth's Ring Plane Crossing in August 1995"): "Our data show unambiguously that the satellite Tethys is a secondary source of material for the E ring."

Now, how do we explain that? Geysers on Tethys seem somewhat unlikely. Couple with that with the sudden very dramatic burst of additional oxygen in the E Ring noted by Cassini's UVIS during its approach, and the E Ring looks like even more of a puzzle than before.

Posted by: David Oct 29 2004, 03:56 PM

No; I think it's another band of rings. The narrowing of the gap from top to bottom would come from viewing the rings at an angle, producing a series of (apparent) nested ellipses; close to the intersection with the minor axis of the ellipse the rings appear closer together, and as you move toward the major axis they seem to move apart; where there are gaps they appear wider.
However, there is something strange about this picture; in trying to determine just what part of the rings I was looking at, I tried to match up the image with a wide angle view of Saturn taken near Oct. 15, and I could not make the match. Also, for some reason, the image number (N00023152) isn't in sequence with other numbers for Oct. 15, which are in the N00021000-22000 range. N00023151 is an image of Titan from Oct. 23. I suspect that N00023152 has been mislabelled or misdated, or both.
N00023152 is listed in the index http://saturn.jpl.nasa.gov/multimedia/images/raw/casJPGFullS04
and its date there is Oct. 25. (The Titan image with the preceding number is in a different folder, casJPGFullS05). I can't find any wide angle views of Saturn from Oct. 25, however.

Posted by: OWW Oct 29 2004, 05:13 PM

Tethys from 253,557 km.

Posted by: OWW Oct 29 2004, 06:30 PM

My crude attempt at constructing a Tethys mosaic:

Posted by: volcanopele Oct 29 2004, 07:20 PM

Not to shabby. One way to make the brightness levels match up is to use photoshop and the curves utility. Select the sliver frame (which should be a seperate layer) and use the curves tool to match up the brightnesses. not perfect, but that's what I did on my released Phoebe mosaic.

Attached is a png file with feature names for Tethys.

Posted by: Bjorn Jonsson Oct 29 2004, 09:34 PM

However, I notice that Cassini seems to have had pointing problems during the Tethys flyby. Even though Tethys is nicely visible in many images there are also many images that only show black space.

I may post a preliminary cylindrical map of Tethys within 24 hours.

Bjorn

Posted by: volcanopele Oct 29 2004, 09:38 PM

apparently the issue is a slight uncertainty in Tethys' position. For reference, the central lat and lon is 22.2N and 272.1W

Posted by: Bjorn Jonsson Oct 30 2004, 09:33 PM

I'm attaching a preliminary map of Tethys where the latest Cassini images have been added to a Voyager-based map. The Voyager map is from http://solarsystem.dlr.de/PG/cassini/planning/ which had maps of Saturn's major satellites but this page has now disappeared or been moved.

This map is preliminary; I haven't removed seams etc. and I corrected only crudely for the varying lighting geometry across Tethys' disk. Interestingly, there seems to be a large and very shallow crater ESE of Penelope (the biggest crater visible in the highest resolution Cassini images). The shape of this crater is probably a bit distorted in the map since it's very near the limb. Hints of this crater may be visible in the original Voyager map.

Posted by: Bjorn Jonsson Oct 30 2004, 09:37 PM

Interestingly Penelope is not circular as the attached rendering shows. This is definitely not an error in the map since it is also non-circular in the Voyager-based map.

Posted by: OWW Nov 23 2004, 09:46 PM

And an even better processed color image:

Posted by: Bjorn Jonsson Nov 26 2004, 09:26 PM

I noticed an error in the caption to the Cassini Tethys color image, Cassini still hasn't passed closer to Tethys than Voyager 2 did:

http://photojournal.jpl.nasa.gov/catalog/PIA01386

In fact Voyager passed Tethys at a distance of less than 100,000 km.
However, Cassini's resolution is better, thanks to a superior camera.

Posted by: tedstryk Nov 26 2004, 11:03 PM

Not to mention that a stuck scan platform cost all of the high resolution Voyager images except the one you linked to which barely caught the moon. That also cost us a high resolution mosaic of Enceladus.

Posted by: Decepticon Nov 27 2004, 02:16 AM

Bjorn I love the work you do!

Always look forward to your images.

Posted by: volcanopele Nov 29 2004, 07:45 PM

I just did some measurements on Penelope, and you're right. The long axis of the crater (~N-S) appears to be 185 km long and the short axis (~E-W) 157 km long. Compare this to Telemanchus near the terminator which appears to be much more circular at 90 km across. Interestingly, the large crater seen along the terminator in previous released images (at http://ciclops.lpl.arizona.edu/view.php?id=297 and http://ciclops.lpl.arizona.edu/view.php?id=273 ) appears to be seen along the limb and appears to be between 100 and 150 km across.

Posted by: Sunspot Nov 30 2004, 12:16 AM

Will JPL release detailed flyby information/timeline prior to each satellite flyby just as they did with the last Titan encounter?

Posted by: Decepticon Nov 30 2004, 03:21 AM

I've lost all hope for this.

Every time Cassini comes in for a flyby, it's a surprise as to what we can expect.

I think its time for some emails sent to the cassini team asking why this info has not been released.

Posted by: YesRushGen Nov 30 2004, 02:17 PM

I remember with the Galileo mission (at least in the primary mission) that a detailed timeline of each flyby was made available showing the encounter geometry and planned observations.

Cassini mission did this for Titan-a flyby, but as already stated, nothing so far for Titan-b.

Posted by: tedstryk Dec 15 2004, 09:19 PM

Check out this shot! That is one mighty big canyon!!!!

Posted by: volcanopele Dec 15 2004, 10:59 PM

Discussion here with that image has centered on that degraded multi-ring basin to the southeast of Ithaca Chasma.

Posted by: remcook Dec 20 2004, 02:44 PM

new picture

http://ciclops.lpl.arizona.edu/view.php?id=668

Posted by: tedstryk Dec 20 2004, 03:11 PM

I colorized the image based on the rough color of Tethys in images earlier in the mission.

Ted

Posted by: Bjorn Jonsson Feb 5 2005, 08:14 PM

I recently finished a new map of Tethys identical to the earlier in this thread except that I addded data from an image showing the southern half of Ithaca Chasma. It is available here:

http://www.mmedia.is/bjj/misc/css_stuff/index.html

The map isn't very pretty, spending a lot of time removing seams seemed like a waste of time until more images are available and until PDS formatted images become available. However, it is considerably more detailed than earlier Voyager-based maps.

Posted by: Decepticon Feb 6 2005, 08:16 PM

Love these Maps.

Has anyone worked on Titan? Or should I be asking this after the next flyby?

Posted by: volcanopele Feb 6 2005, 09:26 PM

I have..my latest version hasn't been officially released yet but you can find a copy here: http://www.lpi.usra.edu/lpsc2005/pdf/1968.pdf

Posted by: alan Feb 6 2005, 11:01 PM

Volcanopele is this the link you were referring to?
http://www.lpi.usra.edu/meetings/lpsc2005/pdf/1968.pdf

Posted by: Decepticon Feb 7 2005, 01:49 AM

<burns>E-x-c-e-l-l-e-n-t!</burns> Love the detail from OI. Looks better on this map.

It says we can find a Hires image on http://ciclops.lpl.arizona.edu

But I seem unable to find it. A lack of a search engine makes it a task and half.