Enceladus = Europa?!

General physics and astronomy discussions not directly related to Celestia
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Evil Dr Ganymede
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Enceladus = Europa?!

Post #1by Evil Dr Ganymede » 17.02.2005, 16:49

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

Image


Oh. My. God. 8O

This terrain on Enceladus bears a very stunning resemblance to the ridges of Europa. It's jaw-dropping...! 8O

lostfisherman
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Post #2by lostfisherman » 17.02.2005, 17:20

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.
Regards, Losty

The Singing Badger
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Post #3by The Singing Badger » 17.02.2005, 18:31

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

Look at this one in particular!! Holy... 8O It looks like frozen icing on a cake...

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

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Post #4by Dollan » 18.02.2005, 05:09

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...
"To make an apple pie from scratch, you must first create the universe..."
--Carl Sagan

Michael Kilderry
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Post #5by Michael Kilderry » 18.02.2005, 06:19

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

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Evil Dr Ganymede
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Post #6by Evil Dr Ganymede » 18.02.2005, 07:06

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...

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Post #7by chris » 18.02.2005, 08:01

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

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Post #8by Evil Dr Ganymede » 18.02.2005, 18:11

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...

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Overexposed Enceladus

Post #9by andersa » 18.02.2005, 19:06

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).
Anders Andersson

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Arcuate feature

Post #10by andersa » 18.02.2005, 19:55

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.
Anders Andersson

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Re: Overexposed Enceladus

Post #11by Matt McIrvin » 19.02.2005, 05:20

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?

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Post #12by Matt McIrvin » 19.02.2005, 05:23


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Re: Overexposed Enceladus

Post #13by Evil Dr Ganymede » 19.02.2005, 10:29

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?

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Post #14by Matt McIrvin » 20.02.2005, 17:46

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.


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