Here's a rough composition of 8 pictures.

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That is quite simply jaw-dropping.

Makes me long for an X-wing Fighter or suchlike, to go flying among those bizarre orbiting rockpiles.

New Cassini ring images released by CICLOPS

ADMIN - Don't copy and paste an entire press release - just link to it.

Sorry about that, I'll keep that in mind for the future.

Anticipation Builds as Equinox Draws Near

They got that right!

Fascinating stuff!
As a chemist I have to say if I saw an image like from a reaction set up, I'd conclude we were growing crystals at an interface

Saturn on August 5th and a large enhancement:
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Looks like Saturn's night side is finally actually dark. I believe the speck above is Enceladus.

Well spotted Alan! this has now been officially confirmed as a ~400m moonlet orbiting just above the ring plane see here

Having seen the recent WAC images showing Saturn and the rings where the brightness of the rings varies in the radial direction and where the brightness is at maximum 'in front of' Saturn's dayside I decided to determine the approximate Saturnshine distribution and intensity on the rings since it currently dominates due to the low solar elevation angle.

This is an unprocessed rendering showing the results. The Saturn/rings brightness ratio is highly approximate (the rings are probably too bright). In contrast, the light distribution and relative intensity within the ringsystem should be fairly accurate:
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And a rendering processed to show the rings more clearly:
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Absolutely brilliant, Bjorn.

I get a kick out of the kick you guys are getting from the new ring revelations. Can't wait to see what you think of this:

Like the fist of an angry god
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The ring illumination effect shown in Bjorn's post is visible in this raw image:

http://saturn.jpl.nasa.gov/photos/raw/rawi...?imageID=197996

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The F-ring looks a bit brighter though, perhaps due to forward scattering of sunlight by smaller particles?

Agreed!!
And, apologies, but I really couldn't resist tinkering with it given it evokes the vinyl format of one of my first childhood encounters with the planets many, many moons ago
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The ring plane crossing has of course occurred. I am looking forward to seeing what Cassini saw, but in the mean time, here is an amateur view (very impressive given the poor location of Saturn) http://alpo-j.asahikawa-med.ac.jp/kk09/s090810z.htm

There's one August 10th raw NAC image, from the day before ring plane crossing, posted so far. I don't have any inside scoop on what it shows, but it appears to be a highly foreshortened upside-down image of the south side of the rings, which were then still in daylight, centered on the point where the D ring exits Saturn's shadow but including the main rings out to the Cassini division. The remarkable thing about it is how bright the D-ring is compared to the rest of the rings- being optically thin it is not hiding in its own shadow, unlike the rest of the ring system.

John

Some of the ringlets of the D ring also have a bit of orbital inclination. Perhaps this is currently helping to keep them out of the shadow of the main rings?

Lots of ring-plane crossing ring images from August 10 and 11 are now posted. Many are difficult to figure out, though here is what appears to be the outer B-ring and Cassini division- part of a scan of the entire ring ansa. The images are very dark, as you might expect.

John

Based on what I've seen so far, the rings seem very flat. I'd expected to see maybe a bit of warping, but it appears not. I'd also expected more "mooms," but there don't appear to be many of those, either.

Since the rings are very flat, I'm really curious how long the actual equinox would take.

I think on the basis of the apparent solar diameter and the rate of change of solar declination we're talking about a day or two.

I did a back-of-the-envelope calculation the other day and came up with a change of inclination of about 0.015 degrees per day. The diameter of the Sun is around 0.05 degrees as seen from Saturn, so it's a few days in total.

The images for the Saturn mosaic taken earlier today have hit the ground. They are not up on the JPL raw images page, but some have been posted on the Cassini Imaging team website:

http://ciclops.org/view_event/113/Equinox_Arrives

This is the Cassini equinox image referenced in volcanopele's post above (raw image 1)
I lightly rinsed it to bring out the contrast and the dark rings were hiding in the dark region in the upper left!
...and that razor of a shadow!

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here is a thumbnail of the original

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exciting times!

One exciting thing is that currently and for the next few years, we are passing through the same Saturnian seasons that were studied by the Voyagers and Pioneer 11. Should make for some interesting comparisons.

You got it right. From a Cassini friend: The entire transit spanned from AUG 09 04:00:00 UTC to AUG 12 21:00:00 UTC, with the Sun's center crossing at AUG 11 00:41:06 UTC.

Here is an interesting shot, N00140443.jpg, which shows a diagonal bright ridge which is angled slightly relative to the normal ring pattern. Positioned to left of middle of shot. Could it be a elongated type of propeller? The previous shot also shows this ridge, N00140442.jpg, so I don't think it is an artifact. Images are from August 13th.

Bizarre. A spiral density wave?

One geometric arrangement that would account for this seeming diagonal would be a ringlet that extends out in a plane perpendicular to the main ring plain, i.e it would be a ringlet that is "taller" than the others. What might cause it? Perhaps a collision or break up of a small body in recent history, such that there hasn't been time for all the debris to settle back down to the common plane that the rest of the ringlets orbit in.

To demonstrate this, cut a long strip of paper and tape it in a loop and set it down on an old phonograph record. Bring your view down to an angle slightly just above the the plane of the record. You will notice that the upper edge of the paper to the right and left of your straight-on view seems to cross the record grooves at an angle like the image above.

Just curious, but we have 2 data points for objects hitting Jupiter and we also know Jupiter's area and mass. Can we extrapolate a rate for objects of a given size to penetrate the Saturnian ring plane ?? And any idea how large an object it would take to make a visible 'ding' ( and I figure it depends on the depth of the ring where it hits), and I assume the math for how fast differential rotation would streak out the blem is easy (but still beyond my ken).

I doubt anything statistically significant can be determined from just two data points.

Look at how dark is edge-illuminated A ring, compared to more diffuse F ring!
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(N00140317 and 319 joined)

Wow, yeah, really! Sure looks like the F-ring shepards scatter a lot more of that ring's material in the vertical plane. I'm sort of surprised that at least the extreme outer rim of the A-ring isn't a bit more luminous in this view.

On the contrary, if we assume the two events were independent and identically distributed, having two of them so close together tells us quite a bit. We can be fairly confident that these events occur at a rate of at least a few per century -- we'd definitely be surprised if they averaged less than one per 1,000 years and yet we somehow saw two so close together.

Of course, that doesn't tell us anything about how often rocks hit Saturn . . .

--Greg

Ring shot from August 15 with horrendous compression artifacts, two moons (I'm guessing Janus and Epimetheus) and a star streak:

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Still pretty awesome. Goooood moooorning, all of you who live on the north side of the rings!

Gordan, "horrendous" to you is a masterpiece to others. Gorgeous!

The moon on the left is Epimetheus, the one on the right is Janus. The star streak is HD 171391, a 5 magnitude star in Scutum.

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Ugordan: Beautiful!

As far as impacts, we have to remember that this recent fragment, while another data point, isn't exactly another SL-9...It is like one fairly large fragment. At any rate, while there might be some disruption, it would take something much larger than SL-9 to seriously alter the rings long term.

More highlighted relief casting long shadows here:

http://saturn.jpl.nasa.gov/multimedia/imag...2/N00141155.jpg

I don't know how long this effect will last, but I find this page incredibly pretty:

http://saturn.jpl.nasa.gov/photos/raw/inde...storedQ=2127676

I thought that this sequence was nice.
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Tried to keep the rings stable in the animation, so the edge of Saturn seems to jump around with the over exposure flaring, but you get the idea. Any idea which moons are seen here?

'tis Tethys at bottom left.

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Colors are fun!

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Animation taken of chunks in Saturn's rings and their shadows rotating along. These were taken August 19, 2009 from a distance of 2.3 million km.

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(GIF-click to animate)

This is from series N00141115-N00141124.jpg

(The astute observer will note a star crossing behind the bright outer F ring in the lower left corner. Might need to look at the full res version to see it.)

A full resolution version is here (2.4 Mb): http://www.flickr.com/photos/31678681@N07/3841882278/ (click on original size to view animation)

-Mike

Zoom of the animated GIF above. I think the chunks are being preturbed by Daphnis in the Keeler gap. You can see the ring shadows thrown across the A ring by the perturbed material.

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(GIF -click to animate)

-Mike

Animation of slides from 141155 to 161, cropped and contrast enhanced:
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Clearly, also in this case there is a gravitational trig at a precise longitude for these perturbations... These shadows in the B ring vaguely recall spokes, which appear near equinox too!

Equinox CHARM:

http://saturn.jpl.nasa.gov/files/20090929_...M_Showalter.pdf

That's a really good slide show. Thanks. I wish I could have heard the talk that went with it.

I've been curious about what details Northern Exposure might reveal, and I'm really looking forward to the WOW factor of a compilation of flybys before and after equinox.

You will be able to when they post the audio and transcript here - usualy within a few weeks:
http://saturn.jpl.nasa.gov/video/products/...aProductsCharm/

EDIT - and if the date there's correct the presentation will not happen live until next Tuesday.

The slides on unwinding the ripples in the C and D rings to some event in spring 1984 were very interesting. I had not seen this discussed before.