An excerpt from Emily Lakdawalla's blog entry today ("Pretty Cassini pictures from near the ring plane"):



I'll only add that Cassini has several "Kodak Moments" planned for the tour. In fact, as Cassini Mission Planning defines them: "These images are *candidate* opportunities for aesthetically pleasing images to be taken. Navigation may consider replacing one OPNAV with one of these images, but only if navigation margin and workforce allow. It is expected that on average, about one image per sequence may be implemented, totaling a few dozen over the tour."

The one planned for the S17 sequence is OK, I guess. It's a nearly edge-on shot of the rings with Mimas, Calypso, and Pan in the frame. S18 has two, one of which has Titan nearly occultating Enceladus. At any rate, expect some dazzling shots of the rings later in the tour, when Cassini is in a high inclination orbit.

How about that. I thought the 'pretty' multiple moons all in one picture were absolutely crucial for precisely measuring the moons positions and Cassini's location amongst them.

Thanx for the deeper insight into the mission planners goals and motivations.

I like those shots regardless of the motivation for taking them.

Most of the multiple-moon shots are indeed for optical navigation, as you say; but op nav images are usually just taken through the clear filter, and usually are one-off shots. To do a "kodak moment" they typically do RED-GRN-BL1 which allows them to create an approximate true color version. Judging from what I've seen on the raw site those RED and BL1 filters are pretty much only used either when they're specifically composing a pretty picture for public consumption or when they're shooting a full set using all filters for spectrophotometry. GRN gets used all the time though.

--Emily

The same as MER

You can tell, if they do something with just L456, it's a Kodak Moment. But L257 is normal

Doug

It seems to be a bandwidth concern, with just CLR or Green as the default, L257 to get some spectral information (also, varying polarization is a rarer alternative), with the rare full-filter set.

As far as Photojournal-level releases, Cassini has led to a surprising proliferation of BW pictures that seem like a throwback to Mariner after, eg, Viking + Voyager were so heavily color-based in public releases. Well, this is a mission-by-mission issue. But as far as PR goes, they ought to stick with the color releases. It would be nice if one of the occultation event "movies" were done in RGB.

The Moons aren't that colourful though - except Titan. A shot of Titan passing in front of Saturn would be nice though.

Yeah, it's true, color would be wasted on those movies. And anyway the movies already take a lot of bandwidth because of the multiple frames -- it's hard to justify tripling the bandwidth in order to get color.

I think that the proliferation of BW on Cassini releases may ironically have to do with just how many filters Cassini's cameras have. A great many of them are devoted to methane bands and continuum bands in the infrared and they use those a lot. Combining several of those into color images makes really cool psychadelic pictures of Saturn showing all kinds of incredible detail in the cloud structure but they look "fake" because of all the colors. Black and white views look more "real."

Perhaps we need more people here to use some artistic license to make more colorful Cassini pictures

--Emily

[quote=elakdawalla,Dec 10 2005, 05:08 PM]
Yeah, it's true, color would be wasted on those movies. And anyway the movies already take a lot of bandwidth because of the multiple frames -- it's hard to justify tripling the bandwidth in order to get color.


Its a combination of allocated datavolume and the typical speed of the mutual events. The transits themselves usually don't last longer than a couple of minutes, some only 20-30 seconds or so. With a frame time of 33 seconds it takes 99 seconds to actually take a RED-GRN-BL1 triplet. With the scientific justification for the observations being orbit determination of the satellites its hard to justify three filter sets just to produce colour images especially if you only have enough allocated datavolume to take 10 images. Then there is the fact that the events are so rapid that the satellites are in different relative positions in every single image so you can't just combine a RED-GRN-BL1 set to make a single colour image. You have to 'fake' things and 'cut out' the satellites from the different filters to combine them.

Bandwidth per se usually isn't the issue its nearly always the absolute allocated datavolume for an observation thats the limiting factor.

And one final tid bit about the KODAK MOMENT images. These observations are planned by Mission Planning at JPL and executed by the NAV team at JPL and specifically CANNOT be used for science. All science images are planned and executed by the ISS team, the Mission Planners at JPL have no input to this process and no data rights, until the archived images are released to the general public by the PDS 9-12 months after they are taken. Only members of the ISS team can do science with all images taken by the ISS cameras before this happens (that includes all OPNAV and KODAK MOMENT images).

This low phase-anghle view of Janus+rings+Titan completeley taken away my breath, I'm still looking for it!
http://saturn.jpl.nasa.gov/multimedia/imag...9/N00055798.jpg

Edit: Do someone wants to make a good movie with the entire sequence?

Here are some movies: http://um3k.justinphillips.googlepages.com...ings-titanevent
Let me know if you need gif versions.

Have they ever taken a large color mosaic of all of Saturn and the rings?

The Greatest Saturn Portrait... Yet

Yes, on October 6, 2004. See coiss_2007\data\1475761489_1475767501

There are a few Kodak Moments for "full portraits" towards the end of the primary tour, especially in 2008 during S39 and S40, when Cassini will be in a highly inclined orbit and looking "down" on the system during portions of its orbit.

Very nice animations, um3K... I would call it a relativistic work!



Very nice animations, um3K... I would call it a relativistic work!
thanks

Looks like another Kodak Moment has just come down in the raws. Here are links to the Red Green and Blue images.

I have lurked around this forum for a while and thought it might be time to contribute (a little) something.




Click to view attachment

Nice work, Dyche... look also to my version

This probably doesn't qualify as a Kodak Moment but I had fun putting this old image together from the raw data.

Click to view attachment

I left the edges of the raw images hanging out as a registration test.

On Apr,28 Cassini taken some beautiful portraits of Epimetheus in front of A/B rings and Titan (already highlighted in another post).
Here below, I report a stitch of two clear-filter images taken in different time in order to have a panoramic view of the rings and a combination of RGB detail of Epimeteus (registration of all objects in the images is impossible due to strong shifts).
Click to view attachment Click to view attachment

Here's a thought:

Galileo captured a few images of Saturn while in orbit around Jupiter; has Cassini captured any images of Jupiter while in orbit around Saturn?

Bob Shaw

Cassini snapped a couple of images through the blue filter before SOI, in May 2004:
http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=13385
http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=13384

Nothing spectacular, I don't know it they were overexposed on purpose or by the raw image histogram stretching function.
This is about the time the earliest posted raw images date back, so that's about the most recent stuff there is.

This is too much ... this is really too much !
( 'famous' sentence from the Voyager era ... )

We're really lucky to be around in this era of solar system exploration, although I would like to view ahead for a century

A rare color image on the CICLOPS site as image of the day. Showing Titan behind the rings : Titan on the Side

This obviously required a bit of Photoshopping because of the motion between exposures.
It's notable how the rings have a uniform coloring to them when there's a moon in the scene. When we have the classic Saturn & rings shots, the rings turn out all colorful (even distinctly blue) and neat and stuff, but the moons also turn out blue as a consequence. Obviously one of the two different portrayals is wrong - my guess is the latter one, going for the PR impact instead of realism.
This shot definitely looks more realistic to me, if less awe-inspiring.

Some examples of the rings with a moon present:
http://ciclops.org/view.php?id=1818
http://ciclops.org/view.php?id=1590
http://ciclops.org/view.php?id=1527 (stretched color)
http://ciclops.org/view.php?id=1466
http://ciclops.org/view.php?id=1007

Compare those for example to this:
http://ciclops.org/view.php?id=722
Admittedly, this one does look more like the real thing, though.

Sheesh, am I bored on my job or what?

*snort* if you're that bored perhaps you could help me figure out if there have been any images of a moon-shadow on the rings. I've followed cassini quite closely and don't recall any. Would there be any rational for taking such an image if the geometary was favourable?

Currently, the lighting geometry at the Saturnian system is such that no moon can cast a shadow upond the rings there. Practically all the moons (w/ exception of Iapetus and far-out Phoebe) are in equatorial orbits, their inclination is negligible. The season is something like late summer for the southern hemispheres and the equinox is just too far into the future for Sun's angle to be right for shadows of that sort. We'll have to wait a couple of years more for that to happen. Even then, the shadows will be very oblique and elongated, because of the equinox and the fact no moon rises significantly above the ring plane.

Hubble imaged Saturn during the latest solar ring plane crossing and imaged Dione casting its shadow on the rings (see the image here).

A very high phase sequence of Titan passing in front of the rings has appeared on the raw site:
http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=77062
The above image also shows one of the small moons, dimly lit by saturnshine, seen here "touching" Titan's haze.

The small moon is known as ...?

Rings behind Titan's Crescent:

Actually these high phase mutual event images show Titan occulting Janus and then Epimetheus.

N00062231.jpg through N00062240.jpg are Janus and N00062241.jpg through N00062243.jpg Epimetheus.

Thanks!

And here's the complete animated sequence:

- Rings, Titan, Janus, Epimetheus (2.25 MB)

Very cool!

By the way: what is that thing at ~2 o'clock on Titan's limb? It looks like an artifact but it seems pretty consistent between the frames.

That would be charge bleeding on the CCD due to overexposure. It's consistent because pretty much all parameters are constant throughout the sequence -- phase angle, exposure time, filter combo etc...

Nice finding. Another moon?

Titan: The never-crescent moon!

http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=77092

It occurs to me that Cassini's current position on a very long orbit, looking at the system from a very high phase angle would be an excellent place to keep an eye on temporal variability of Enceladus' plumes. From what we've seen so far, they're pretty much constantly churning out water.

Somehow that image seems really freaky. The lighting looks like its all wrong. Encaladus is mostly in shadow, but the moon behind is not (I'm guessing it's Rhea).

Is the moon behind on the other side of Saturn and so more in Saturnshine than Encaladus?

Yes, the other moon (I believe it's Tethys) is on the far side, above the sunlit side of Saturn so its Saturn-facing hemisphere receives a lot of saturnshine. Enceladus, on the near side, is above Saturn's nightside and it's thus showing us the hemisphere facing away from Saturn.

Here I removed most of sensor noise pattern:
Click to view attachment
In addition to illumination, another hint about Tethys distance is the "fog" effect caused by G-ring, which lies mostly between the two satellites.

Incredible sequence now in the raw section, with Enceladus passing in front of Titan + rings + Tethys.
Here a spectacular stitch of two pictures (I know, we should have ONE Enceladus, not two... ):
Click to view attachment (original images: N00062413+N00062417)
The inset show the enhanced view of Enceladus with plumes!
Below the geometry of view (from space simulator):
Click to view attachment

And this is EPIMETHEUS transiting in front of the giant:
Click to view attachment (original image: N00062411)

(all images were processed in order to reduce jpeg artifacts and improve sharpness/contrast)

A perfect example of weird optical effects: Rhea transiting Titan.

Light from Titan, scattered in the optics, makes Rhea's dark limb look notably trimmed. Shows how you have to be very careful in interpreting these kinds of images.

Cassini is churning out stunning images like a factory! Here's another one:

http://photojournal.jpl.nasa.gov/catalog/PIA08207

Absolutely! and this one is even more impressive... these incredible views strongly recall wildest scenes from best SF movies

This recent image on the Cassini website is a Kodak moment for Bob Shaw.

Teke-li-li!

Cassini took a picture when it was travelling fairly close to Saturn. To me, it looked similar to some pictures of Earth taken by people on space shuttles in orbit. For that reason, I decided to put Bruce McCandless into the photograph of Saturn.

Tons of new Saturn-and-rings pictures today. Check JPL Photojournal.

Check out

http://photojournal.jpl.nasa.gov/catalog/PIA08361

but don't panic... Saturn is still there.

There's a brief image advisory on the Cassini website.

Note a peculiar thing in this image. Bjorn noticed it back in Ian Regan's mosaic that the rings were too bright around the planet's shadow. The feature is obviously real, the question is: how come? Phase angle effects, similar to opposition effect but on the unlit side? Weird...

(Only tenuously thread-related, sorry...)
Just noticed a satellite shadow on Saturn in the raws (1, 2, 3, 4). We don't see that very often, although I guess it'll become more and more common as we approach the solar ring plane crossing in 2009.
(Note: some frames were reduced in size in the animation.)
Click to view attachment