[X] My Assistant

[Guest_Sunspot_*]

http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=26004

[djellison]

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 )

[volcanopele]

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

[Bjorn Jonsson]

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

Attached thumbnail(s)

 

[Guest_Sunspot_*]

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 )

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/imag...eiImageID=26030

[OWW]

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.

[David]

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.

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?

[OWW]

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

[Guest_BruceMoomaw_*]

By the way, has anyone noticed one eyebrow-raiser among the new AGU Fall Meeting abstracts? http://www.agu.org/cgi-bin/SFgate/SFgate?&...t;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.

[David]

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

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/imag...w/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.

[OWW]

Tethys from 253,557 km.

[OWW]

My crude attempt at constructing a Tethys mosaic:

Attached thumbnail(s)

 

[volcanopele]

My crude attempt at constructing a Tethys mosaic:

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.

Attached thumbnail(s)

 

[Bjorn Jonsson]

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

[volcanopele]

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

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