Celestia Forums

http://saturn.jpl.nasa.gov/multimedia/i ... ageID=1373




Oh. My. God.

This terrain on Enceladus bears a very stunning resemblance to the ridges of Europa. It's jaw-dropping...!

Yeah, I've been looking at some of the raw images this afternoon, I didn't expect Enceladus to look so, er, crazy. Thanks to Anders for pointing them out so early, as he says use the raw search facility.

http://saturn.jpl.nasa.gov/multimedia/i ... geID=32294

The right edge of some of them have suffered a bit, but there are some wonderful views there.

Check out the CICLOPS pages, they have some hastily processed images.

Look at this one in particular!! Holy... It looks like frozen icing on a cake...

http://ciclops.lpl.arizona.edu/view.php?id=847

Absolutely fascinating. It's almost as if the moon's side has been turned to the consistency of melted plastic! Bugger, I'm mad that I missed these releases (I've had THE nastiest flu for the past week).

...John...

Looks more like a wrinkled sheet to me. Europa looks far less strange.

Michael Kilderry

Michael Kilderry wrote:Looks more like a wrinkled sheet to me. Europa looks far less strange.

Does look kinda like a crumpled plastic sheet doesn't it... but there's clearly something really wacky going on. lots of lateral faulting going on too - you'll notice that things don't seem to line up between the separate terrain blocks...

Here's a link to a paper discussing the mechanism for tidal heating of Europa:

http://swiss.csail.mit.edu/users/wisdom ... dus-aj.pdf

It's a trickier case than Europa, as the orbital resonance with Dione isn't enough to cause enough heating to produce the observed surface features.

--Chris

http://saturn.jpl.nasa.gov/multimedia/i ... geID=32339

Another very cool image. I think the overexposed bit on the right is lit by sunlight, and the crescent on the left is Saturnshine? (Saturn's in the background).

Notice the dark arcuate feature near the day/night terminator... big crater rim or just a ridge? I think it's the latter...

Evil Dr Ganymede wrote:http://saturn.jpl.nasa.gov/multimedia/images/raw/raw-images-details.cfm?feiImageID=32339

Another very cool image. I think the overexposed bit on the right is lit by sunlight, and the crescent on the left is Saturnshine? (Saturn's in the background).

It's Saturnshine on the left, but the background is overexposed space rather than Saturn itself. This particular image was taken 02/17/2005 12:15 UTC according to the raw image archive timestamps, when Saturn should be far left of Enceladus as seen here, not behind it. Even though Celestia's knowledge of Cassini's position may be a little imprecise, it shouldn't matter too much at this distance (over 300,000 km).

Note the bright, horizontal streak below Enceladus; I suppose it's a distant star indicating the duration of the exposure. Experimenting with Celestia suggests it to be around 2 minutes (although I can't identify the star).

Evil Dr Ganymede wrote:Notice the dark arcuate feature near the day/night terminator... big crater rim or just a ridge? I think it's the latter...

I guess you are right, but this is close to the part of Enceladus for which Celestia doesn't have much map detail yet. It's right below areas that were imaged in full daylight during Cassini's approach, but I haven't studied all the images in the archive (and I suppose more images are still waiting to be added).

Evil Dr Ganymede wrote:Notice the dark arcuate feature near the day/night terminator... big crater rim or just a ridge? I think it's the latter...

It looks more like a canyon to me, to the right in this image (W00004830, taken 02/17/2005 03:03 UTC) if I'm not entirely mistaken about its location.

andersa wrote:It's Saturnshine on the left, but the background is overexposed space rather than Saturn itself.

If that is so, how could the dark part of Enceladus possibly be that much darker than space?

Here's a really splendid Enceladus mosaic.

Matt McIrvin wrote:

andersa wrote:It's Saturnshine on the left, but the background is overexposed space rather than Saturn itself.

If that is so, how could the dark part of Enceladus possibly be that much darker than space?

Matt has a point there .
It's got to be Saturn in the background unless.... hmm. Maybe Anders might be correct in a way - could we be seeing Enceladus silhouetted against light scattered from E ring dust in the background?

Yeah, after I posted that I was thinking maybe the background is either the E ring, or zodiacal light.

The background has strange specks in it that might be overexposed stars, but with exposures this long you usually see cosmic-ray glitches all over as well.