I was thinking Janus, but obviously it cannot be the case since the eclipsing moon is smaller even though it is closer. I must be either Pandora or Prometheus. Pandora is more likely.

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

Just wanted to add this Enceladus image to the thread.

It says that what we see here are "fountains of ice", I'm not sure why they say this, because it looks anything but "fountainous" to me. The streams are wispy and leave the surface under an angle. It would be better to describe them as streamers, just like solar streamers or cometary jets.
Also they originate from the "tiger stripes", which don't even look like volcanoes at all. This way of naming the phenomenon "ice volcanoes" is an example of using Earth-based descriptions to basically unknown structures, I think this can be misleading.

Cheers.

On the other hand, even on Earth volcanic phenomena include not only shield and stratovolcanos, but cinder cones, spatter cones, geysers, and vast flows of lava emanating from fissures that didn't build up any elevation above the surroundings, so these plumes don't seem that much of a stretch in the "stuff pushed above the surface by internal heat" department. It would be just as much of a mistake, I submit, to limit "volcano" to terestrial manifestations.

There's only the Cassini images and spectra from Enceladus to go by, and we don't need a stretch of the imagination to try and explain what we see, only facts; we don't know that an internal heating mechanism is at work, or what confines whatever mechanism to one pole. What can be seen of the "plume(s)" shows some structures that look like streamers leaving the surface under an angle, not "fountains" which should either be straight, or cloudlike, don't you think?

Cheers.

cheers.

Cassini's Photo Album From a Season of Icy Moons, incuding movies of Iapetus and the plumes of Enceladus, as well as closeups of Rhea and color variations on Rhea, Dione, and Hyperion.

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

I'm just a sucker for the Planetary Photojournal thumbnails:

Cosmic Blasting Zone


Enceladus Plume Movie


Rhea: Full Moon


Catch that Crater


Iapetus Spins and Tilts


Season of Moons


Color Variation on Hyperion


Color Variation on Hyperion (Currently mistitled; actually Rhea and Dione)

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0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 ...

The plumes of Enceladus are nothing like fountains as the Cassini team mentioned earlier, the similarity to comets has been acknowledged:

Funny that we need two different explanations for one phenomenon, while actually both explanations seem unlikely.

Cheers.

Overview from Ms. Emily at the Planetary Society:

Cassini Completes Initial Reconnaissance of Saturn's Icy Moons

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Everything I need to know I learned through Googling.

Well, I guess we won't be getting as may pretty pictures back from Cassini for a while, but looking at the schedule, it still looks as though there are a number of non-targeted flyby's coming in the next year or so, and I'm guessing the team is not likely to pass up the opportunity to snap a few photos on the way back.

Emily's recap is excellent. Awesome, just like the mission.

Things are only going to get better: The gravity runs scheduled during the dark approaches will provide us with the most puzzling data sets ever, although it will take a while to reduce the data.

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jwj

It's ok not to know. We should try harder to find out.

The Cosmic Blasting Zone looks like a giant sea sponge!

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I am Mugs, of the Alien clan of Usa, Nordamerica, a Terran, of Sol. A human.

Whoever says "perception is reality" is daft. It's merely an abstraction, and often not a very good one.

Christmas present from the CICLOPS team, high resolution maps of the icy satellites and some breathtaking color images:

* Saturnian Cartography - very high resolution maps of all classical Saturnian satellites
* Titan's Halo
* Cassini's Galactic Aspirations - image of the Eta Carinae Nebula
* The Face of Beauty
* Dazzling Color
* Rhea Eclipses Dione (Animation)

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

For fellow occultation fans - here's hoping the Kodak-moment scheduling managed to work in some wide-field images when Saturn slips behind Titan after Cassini's flyby tomorrow around 2100 UT. There was a little bit of Saturn seen through the atmosphere during one of the early passes, but the spectacle potential is great.

Aaaaaaahhhhhh. One of a series of about 30 frames. GIF animation, here we come!

Merry Christmas from Cassini:

Mimas and Helene

Dione and Tethys

Iapetus

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Everything I need to know I learned through Googling.

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Everything I need to know I learned through Googling.

Wow! Somehow I missed that one. Thanks for posting it.

Wonderful view of three moons, part of a Janus movie. The other small moon is probably Epimetheus, hard to say which moon the large one is.

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Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool.
-- Richard Feynman

I've seen most of the images posted here as Saturn, together with Mars, isone of the planets I reguarly "visit". They are certainly wonderful & I love to collect them!!! I shall have to update my space website with these images! (It seems a shame to "hoard" them to onesself like a squirrel!)

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"A wild scheme, it would be useless undertaking”

Charles Darwin's father on hearing of his son's plans to join HMS Beagle

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