[X] My Assistant

[alan]

Three days away!
http://saturn.jpl.nasa.gov/multimedia/imag...fm?imageID=1361

[Decepticon]

WOW! Lots of coverge!



Looks like filling Low res images will be fun for the Mapers.

[Guest_Sunspot_*]

There are a few pictures of Enceladus coming in, these are on the CICLOPS site, they haven't appeared on the JPL RAW page yet

http://ciclops.lpl.arizona.edu/view_event.php?id=11

Only a few hours to go until closest approach

[Decepticon]

And I though Europa was melting.

One side looks totally reworked.

[Guest_Sunspot_*]

In the latest image, parts of the Moon, particularly towards the lft limb, seem to resemble some of the cracks seen on Europa.

[alan]

first group of raw images of enceladus are up

[SFJCody]

[Decepticon]

OMG! I'm Floored!


This moon looks more like Ganymede!

How deep can those grooves be?

[Bjorn Jonsson]

Enceladus looks even more strange than I expected - remarkably similar to Europa in fact. And I can't see a single impact crater in this image (there are a few features that at first glance looked like craters but I think they are mounds).

[SFJCody]

That deep fracture is impressive!
The young areas of Enceladus seem to show a much greater range of topography than Europa. If so, Enceladus' putative ocean/warm ice is likely *less* accessible today than the one belonging to its smooth jovian cousin. This area of the crust must be cold and brittle to great depths to support these topographic features. It looks like we arrived too late.

[Bjorn Jonsson]

Having looked at more images I now realize that what I first thought were craters and then thought were mounds really are craters:



There are both ridges and grooves there. Looks like a strange mix of Europa and Ganymede to me. However, judging from the craters at least this area is hardly active now.

[SFJCody]

There are both ridges and grooves there. Looks like a strange mix of Europa and Ganymede to me. However, judging from the craters at least this area is hardly active now.

Perhaps Enceladus went through successive stages of Europa-like 'cracked-eggshell' terrain and Ganymedean 'ridges & grooves' tectonism as the warm-ice retreated to greater depths. The process seems to have ended with these deep (Dione-esque) fractures.

[Guest_Sunspot_*]

Why is there so much missing data on the right hand side? Can they correct that?

The ridges in this shot look quite like the ones on Europa

http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028194.jpg

[tedstryk]

Looking at the distant images, I don't think these show the very youngest looking terrain that we saw on TC. There may be some younger terrain yet on this moon.

[djellison]

Why is there so much missing data on the right hand side? Can they correct that?

It's not missing - it's interlaced

[tedstryk]

http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028164.jpg

This image shows what I am talking about. If you look at the lower right, there seems to be some kind of terrain is at this resolution craterless and appears to be on top of the terrain we are now looking at, even possibly cutting one crater in half. I wonder if E4 will get us coverage of this!

[Guest_Sunspot_*]

Why is there so much missing data on the right hand side?  Can they correct that?

It's not missing - it's interlaced

.....ummmmmmm what does that mean lol

Whenever I saw pictures like that I always assumed it was a problem with the camera lol

[djellison]

Not sure exactly what it means - but if I de-interlace it in photoshop, it goes away

Doug

[Guest_Sunspot_*]

http://www.planetary.org/news/2005/cassini..._peek_0216.html

The images posted above were captured only hours ago. They were posted on the website of the Cassini imaging team as part of a new effort to get images from the most interesting encounters out to the public as quickly as possible. Not all of Cassini's images will be released in this way, but unlike the images available on the Jet Propulsion Laboratory's Cassini raw images website, these so-called "raw preview" images have been processed to remove noise and artifacts caused by imperfections in the camera hardware and electronics.

Lots more HERE

[Stu]

Just staring in awe at this image...

http://ciclops.lpl.arizona.edu/ir_index.php?id=10

("Preview 6")

[volcanopele]

Why is there so much missing data on the right hand side?  Can they correct that?

It's not missing - it's interlaced

.....ummmmmmm what does that mean lol

Whenever I saw pictures like that I always assumed it was a problem with the camera lol

In lossless compression mode, we tell the camera to expect a certain number of bits per line. In this case the entropy in the images combined with their higher bits per pixel caused us to go over that estimate. When that happens, the camera stops reading out every other line and we get truncated lines. Over-estimating is also bad since the bits per pixel is used to estimate our data volume, which is carefully negotiated between the various instrument teams. If we over estimate, we would have to plan for fewer images.

[DEChengst]

Two quick mosaics:

http://paranoid.dechengst.nl/saturn/Enceladus1.jpg

http://paranoid.dechengst.nl/saturn/Enceladus2.jpg

EDIT:

Because I couldn't get the brightness difference between images corrected in a good way, I replaced #2 with a non corrected one. Correcting made one part of the image look good and the other not very good so I decided to go for the best detail in the images and just accept the brightness differences.

These two images show what happens if I do correct for the brightness differences:

http://paranoid.dechengst.nl/saturn/Enceladus2a.jpg
http://paranoid.dechengst.nl/saturn/Enceladus2b.jpg

[erwan]

Thank you DEChengst for Enceladus mosaics. I prefer the uncorrected for brightness version of the mosaic. Have you tried to apply a kind of black to white gradient Y mask to each frames before stitching? Maybe this could help to correct brighness differences? I have try such an analogous method to eliminate "vignetting" in MER pancam images before stitching, with some results...

[djellison]

http://mer.rlproject.com/enc_ir3_g_uv.jpg

http://mer.rlproject.com/enc_narrow_1.jpg

Doug

[Guest_Sunspot_*]

Did they take any images around closest approach? The closest image I could find so far was about 7000 miles.

[volcanopele]

Did they take any images around closest approach? The closest image I could find so far was about 7000 miles.

yes, but they haven't been played back yet. They were supposed to last night but I'm guessing it will carryover to tonight's downlink

[fredk]

Anyone know the geometry of this encounter? We must be seeing Enceladus against the dark side of Saturn in this image: Casini image

Extremely cool!

[alan]

I saw that earlier, the caption said Saturn was in the background.

[Guest_Sunspot_*]

New RAW images posted as Cassini looked back at Enceladus - but no high res images at closest approach Maybe during the next flyby.

[tedstryk]

I think it is more likely that they just haven't been released. During the Iapetus flyby there were missing images on the "raw" page for the longest time.

[Guest_Sunspot_*]

Some scientists have suggested that material coming from Enceladus maybe be forming Saturn's E ring. One of the objectives of the flyby was to look for evidence of "ice volcanoes".

http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=32339

In the RAW image above, you can see a faint "stream" coming off Enceladus. Is it a simple case of the camera over exposing a specific feature on the moon, producing a flare like feature coming off the surface - or evidence of something else? What do you think?

[tedstryk]

http://saturn.jpl.nasa.gov/multimedia/imag...8/W00004837.jpg

One of the close images of Enceladus is down. And this is WIDE ANGLE!!!!!

[OWW]

Strange. The Ciclops site says it is a narrow angle image taken from 240000 km.
http://ciclops.lpl.arizona.edu/view.php?id=861

[tedstryk]

It has now disappeared from all raw searches, although the link still works. This convinces me that there are more images from the flyby they are not showing. Not that I blame them. But I am convinced there are more.

[volcanopele]

I will try to address some of the questions here:

ObsessedWithWorlds: Obviously that distance is not correct. That is a Wide-angle image and the caption writer probably didn't realize that when he wrote it. Except that still doesn't explain it since that image has a pixel scale of 90 m/pixel. For orientation purposes, the squarish feature near the top of that frame, half way between the right edge of the frame and the limb, is the same feature as the squarish "crater" below and to the right of center in http://ciclops.lpl.arizona.edu/view.php?id=846

Sunspot: we initially got excited about that image as well. I have 60 emails from last night to prove it Unfortunately, it looks like that's just a camera effect, similar to one seen last month in the same area in crescent views of Enceladus (at differing lat/lons), Rhea, and Mimas.

tedstryk: we were supposed to have 9 m/pixel imaging near the limb coinciding with that 90 m/pixel wide-angle image. Unfortunately, it looks like we missed Enceladus just bearly. This was not unexpected, the pointing was expected to be not perfect for this encounter since we couldn't do a live update following the Titan flyby. In fact, that 85-175 m/pixel global mosaic was supposed to be full disk but the mosaic was off by half a frame to a third of Enceladus. The 60 m/pixel frame seem at http://ciclops.lpl.arizona.edu/view.php?id=848 was planned to be centered near the N-S spotted terrain seen at http://ciclops.lpl.arizona.edu/view.php?id=855 .

fredk: that is saturn in the background. If you merge UV3-GRN-IR3, you get a green saturn

[DEChengst]

Have you tried to apply a kind of black to white gradient Y mask to each frames before stitching? Maybe this could help to correct brighness differences?

I'm no Photoshop expert so I wouldn't know how to do that

[alan]

If that is a cryoflow in this image perhaps the dark spots are skylights

http://saturn1.jpl.nasa.gov/multimedia/ima...8/N00028183.jpg

[tedstryk]

Does anyone know the ground track yet for e4?

[Decepticon]

JPL will wait till the last few days before the flyby to release that.

Maybe Bjorn might post something on it?

[OWW]

Nice composition. Enceladus and the rings:

[tedstryk]

Check this one out!

Attached thumbnail(s)

 

[Guest_Sunspot_*]

Dione and the rings...... and possibly tiny Janus?

http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=32866

[alan]

It looks like the latest gravity assist put Cassini nearly in the ring plane, the rings are almost edge-on now.

http://saturn.jpl.nasa.gov/multimedia/imag...8/W00005056.jpg

We probably will be seeing more shots with multiple moons like the one of Dione and Titan.

[Guest_Sunspot_*]

http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=32817

[tedstryk]

It is too bad there isn't a shorter exposure twin for that image.

[akuo]

Whoa, these images are phenomenal.

[OWW]

Tethys and the rings... :

http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028465.jpg

[OWW]

Check this one out!

The file is called titantethys, but it is really Titan with Dione... Just FYI.

[OWW]

Let's not forget the small ones:

Mimas:
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028510.jpg

Janus:
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028462.jpg
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028515.jpg

Epimetheus:
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028617.jpg

Pandora:
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028516.jpg

Prometheus:
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028463.jpg
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028512.jpg
http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028618.jpg

[tedstryk]

My mistake. It is fixed

Images like these really show us what we missed with Galileo due to the antenna problems.

[Guest_Sunspot_*]

In this RAW image of Janus, you can see a faint diagonal stream crossing the tiny moon, the JPEG artefacts in the image are arranged horizontally in bands....Could it be a faint stream of material the JPEG compression has highlighted. Perhaps the original uncompressed image would show it more clearly.


http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028515.jpg

Same thing with tiny Epimetheus:

http://saturn.jpl.nasa.gov/multimedia/imag...8/N00028617.jpg

[edstrick]

Regarding the image<s> of Enceladus with a possible plume in the south polar region. There is a series of short exposure images of the crescent on the JPL RAW pictures pages and a longer exposure (posted on the CICLOPS web page as "862-1905-3", cleaned up and without JPG artifacts). An even longer exposure on the JPL RAW pages is N00028218. The images show Enceladus as a thin crescent, illuminated by sunlight from about a 4:30 clock angle and as a fatter crescent, illuminated by Saturn from the 9:00 clock angle.
The unilluminated side of the moon between the crescents is visible in silhouette against a lighter background. This background is *NOT* the ring-lit nightside of saturn, 1.) since the dayside of saturn is to the left and out of the image, and 2.) because all images show stars or nearly horizontal star-trails, all parallel, tilted slightly down to the right, and varying in length in proportion to the exposure. I have to conclude that we are probably seeing the diffuse E-Ring in forward scattering, with Enceladus between the spacecraft and the bulk of the E-Ring.
I'm attaching a composite image with the two images named above, and two spatial-bandpass-filtered enhancements of 862-1905-3. These have been processed to enhance fine detail in the plumelike feature close to the moon's limb, and details further away from the limb. None of the images, including the long exposure N00028218, show any trace of the feature against the darkside of the moon above the sunlit crescent, and structures in the plumelike feature converge on the bright limb just like cometary jets seen at comets Halley and Borelly and Wild. There seem to be maybe 3 "sources" for the main plume-like feature and a fainter single-source plume-like feature to the right.
Except for a faint diagonal line "behind" Enceladus, visible in the last picture, which I suspect is a camera artifact or something, all features in this image seem consistent with the plume-like feature being real, not light scattered by contamination in the camera (which is a problem with the NA camera) or a lens-flare. I would have to see the images of other moons with simlar faux-plume features referred to a couple days ago by a team member (earlier in this thread) and apply contrast stretching and enhancement to them (using clean versions, not RAW's from the JPL website) to convince me this feature is not real and is not active plumes from Enceladus.

Attached thumbnail(s)

 

[Guest_BruceMoomaw_*]

Personally, I'm waiting to find out whether Cassini detected any signs of outgassing with its multiple instruments suitable for that purpose (UV, mass and plasma spectrometers; dust analyzer).

I do note that two of the new LPSC abstracts reveal that (to the surprise of their experimenters) the UV and plasma spectrometers have not detected any sign of a nitrogen torus in Titan's orbit, indicating that at this time it is losing little nitrogen -- but there is a strong nitrogen torus centered on the E Ring, suggesting that something in that area is emitting ammonia. Enceladus would seem to be the obvious suspect. It HAS already been announced that its VIMS surprised evryone during the close flyby by not detecting any signs of frozen NH3 or CO2 on Enceladus' surface, which seems to be almost pure water ice. Is it possible that the water/ammonia mixture expelled from Encealdus' vents is warm enough that all the ammonia and CO2 vaporize and escape from the moon completely, leving just pure water ice behind?

[Bjorn Jonsson]

I have now updated my Cassini page by adding a new simple cylindrical map of Enceladus based on three T3 images. It can be seen here:

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

[volcanopele]

I have now updated my Cassini page by adding a new simple cylindrical map of Enceladus based on three T3 images. It can be seen here:

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

Very nicely done, Bjorn!!

[cIclops]

has there been an official statement from the Cassini folks about the cause of the pointing error during the T3 Enceladus close encounter?

[alan]

They expected pointing problems:



"A mission plan has not been made available for the Enceladus encounter, because it is a "nontargeted" flyby. Nontargeted flybys are targets of opportunity that occur because of a fortuitous alignment of the moons with Cassini's orbital path, while targeted flybys are set up with careful application of Cassini's thrusters to ensure that both the moon and the orbiter are in the same place at the same time. Cassini mission planner and Ultraviolet Imaging Spectrograph team member Amanda Hendrix explained that "because we are just two days after Titan-3, and it's not a targeted flyby" involving a thruster maneuver to trim the orbital path, "the orbital uncertainties will be high." This is especially true after a relatively close flyby of Titan, when Cassini will actually feel some drag from the outermost reaches of Titan's atmosphere."



"At the closest approach point, the cameras would be capable of images with resolutions as high as 9 meters per pixel, but it's not certain that these pictures will be captured. "At closest approach, we can't track Enceladus, since we're going by so close and are on [reaction] wheels," Hendrix explains. Cassini's reaction wheels are a more efficient way of pointing the spacecraft, but they cannot slew the spacecraft's pointing as quickly as the thrusters can, and Cassini will be moving very quickly past the closest approach with Enceladus. So while the cameras will be taking pictures at the closest approach point, mission planners can't be certain that Enceladus will be exactly at the spot where the pictures are being taken. "

From Planetay Society article for Feb 10
http://www.planetary.org/news/2005/cassini..._plan_0211.html

No Titan encouter before the next Enceladus flyby so this problem shouldn't reoccur.

[scalbers]

Greetings,

I had noticed that apparent plume also, glad to see it being discussed. I wanted to pass along that I have been working on a cylindrical Enceladus map the past few weeks. It's now in reasonably good shape to get ready for the next encounter this coming week. You can see this at my web site URL:

http://laps.fsl.noaa.gov/albers/sos/sos.html


Later,

Steve Albers

[Decepticon]

^ I love your Site!!!! Keep the excellent the work UP!

[teck]

Have a look at this image: is this a geiser at the bottom left end of the long fissure?

Attached thumbnail(s)

 

[teck]

After some investigation, I did a small movie around the "geiser" image. It look like something is going on in this area. Unfortunately, we cannot see further down the image. For this movie I used those images: N00030070.jpg N00030071.jpg N00030072.jpg

If you look straight up the images, you see a wide valley with semi-cicular features which could be coming from this outpouring of "stuff" from a sort of moving "hot spot" under the crust or a moving crust. Does this make sense?

Thanks

Attached thumbnail(s)

 

[Decepticon]

Neat, But I'm not sure where to look?

Is there any way to stable the image better?

[ilbasso]

There's definitely something there that is blurrier than the rest of the image - that puff or whatever stays blurry even as the rest of the image sharpens. Unless it's a reflection in the lens, it has to be a cloud of some sort.

[Bjorn Jonsson]

Simply looks like a smooth crater to me.

[Gsnorgathon]

Not everything that looks blurry is a cloud. I've seen quite a few MOC images where you'd swear the image was out of focus, but then you notice some feature, maybe a small, fresh impact crater, and realize that the image is in fact quite crisply focused and the landscape itself is blurry.

The 14 March 2005 MOC image of the day provides a reasonably good example. The dunes themselves are fuzzy, but if you look closely at the space between the dunes, you'll notice there's quite a lot of fine detail.

[alan]

Here is a better view of the blurred area, near the center of the image
http://saturn.jpl.nasa.gov/multimedia/imag...eiImageID=34966
The crater is on top of the fissure, therefore younger, the blurred area is its ejecta blanket.

[remcook]

that would make sense, since all the craters seems to be blurry compared to their surroundings

[volcanopele]

or, the fracture propagated through the ejecta blanket of that crater and due to the weak regolith surrounding the crater, mass wasting is enhanced in that area of the fracture.

[Decepticon]

"Something Funny Is Going on at Iapetus and Enceladus"



http://www.planetary.org/news/2005/cassini_moons_0322.html