CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Enceladus '61EN' Flyby Raw Preview #4

Enceladus '61EN' Flyby Raw Preview #4
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  This raw, unprocessed image was taken during Cassini's very close approach to Enceladus on March 12, 2008.

The image was taken with the Cassini spacecraft narrow-angle camera on March 12, 2008 a distance of approximately 32,000 kilometers (20,000 miles) from Enceladus. Image scale is 190 meters (623 feet) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission, visit and the Cassini imaging team home page,

Credit: NASA/JPL/Space Science Institute
Released: March 13, 2008
Image/Caption Information

Alliance Member Comments
NeKto (Jul 30, 2008 at 1:53 PM):
I was looking at the details of the Messenger images from Mercury published in "Science." To my eye there are similarities. The rims of many of the Mercury craters don't appear as "relaxed" to my eye as those on Enceladus, but the floors appear similar. just looking at them, the notion comes to me that the material in the bottom of the impact was warm enough in both cases to be more elastic than craters formed elsewhere.
i will be very interested in what the measurements and science have to say about the crater formation processes on these two bodies.
Mercury_3488 (Mar 29, 2008 at 12:59 PM):
Hi Tsesarevich.

Your idea backs up my impact theory. There is nothing seen in either the images or during the data release a few days ago, that suggests otherwise.

I reckon all current activity on Enceladus is fossil heat from a very large impact, in the very recent geological past.

The Tiger Stripes to me looks like skin on paint in a paint pot with no lid hardening, or in this case, ice slowly freezing over a huge impact basin. Beneath the fresh ice layer, there may be liquid water, in fact I think it is certain that there is liquid water, but is only a temporary phase, before the whole lot freezes solid, all the way down.

Some tidal heating is possible between Saturn on one side & Dione on the other, but in all fairness, Enceladus is really far too small to be affected greatly by such a situation.

I think we are looking at a major impact scar healing over. The softening of northern craters, probably reflect heat through shockwaves from the impact.

Andrew Brown.
NeKto (Mar 29, 2008 at 11:46 AM):
i too was struck by the unique character of the craters in this image. i've not seen the like of them anywhere else. the closest thing i've seen is ant lion traps in sand. My first thought was perhaps the energy of impact was enough to turn something in the sub surface to slush. perhaps carbon dioxide and or amonia were liquified enough to lubricate the underlying ice crystals.
I'll wait and see what the experts come up with.
By the way Carolyn, i still think you are having too much fun at work. we all should be so lucky!
carolyn (CICLOPS) (Mar 13, 2008 at 4:00 PM):
Harry: The characteristics of the craters in this region -- very relaxed, with bowed floors -- tells us that the ice in which they were created was, or became, warm which degraded and softened the appearance of the craters. And maybe this is due to warmth in the interior sometime during the past. This was suspected even in Voyager days. But we have no evidence that the north pole is warm...certainly not as warm as the south ... so it is not likely at all that there is liquid water within the near sub-surface of the two craters you refer to. And not likely that there would be geysers streaming out of them.

But good thinking! It's fun to see what all of you are thinking. Keep it up.
Harry (Mar 13, 2008 at 12:01 PM):
This image is amazing! I know it is way too early for interpretations of the geologic features shown but, I can't help myself. Besides, what do I know about what water ice(?) is going to do at 0 atmospheres and extremely low temperatures/gravity.

Presuming that there is a subsurface liquid region, the two craters near the image center look as if they might be meteor craters that punched a hole deep enough to stimulate geysers.

There seems to be a fault extending over the limb at right center of the image. That could be an extension zone in the brittle surface ice. If so, what differentiates it from the curved "cracks" at the top of the image? Is is location, proximity to the thermal hot zones or could it be tectonic movement smoothing the fault fault lines on top?

So many questions from just one camera image! The other insturments will need to provide data for proper interpretation. I will have to wait as patiently as I can for the expert interpretations that will be forthcoming in the months (& years)to come.

Thanks so much and congratualtions! Harry in Houston