That second image is striking to me in that the plumes are so big. They appear to be a thousand miles high or more. How fast must the ice particles be shooting out of those geysers to go so high, and even escape the moon!? I know some of the fall back down, but I’ve read that one of Saturn’s rings is formed by such particles.

I’m also surprised that the geysers are visible in an image that was exposed for the moon itself. I didn’t think they had enough density to really be seen unaided. Or perhaps the image was made in a wavelength where the plumes are much brighter compared to the surface?

Read the link.

Which is it?

Beats me. I’m a violent star-explodey kind of guy, not an exooceanologist. I imagine the authors of the two papers have their opinions on both studies, and I’d love to hear what they have to say. I’d also like to see the spectra obtained by the no-salt-in-the-plumes team first (because a non-detection of something is always on shakier ground than a positive detection of something) before I would come to any conclusions.

But thus is science. Two observations, two good teams, two very different conclusions. That’s what it’s like on the cutting edge… and we’ll need more observations to cut through all this. Happily, as Cassini orbits the Saturn system it will be passing directly through the plumes at least twice more, giving astronomers that many more chances to see what’s happening on that tiny little moon so far away.

One chance down. They have had plenty of time to analyze the data, but still haven’t reported whether or not the plume is fresh water or salt.

How do you know that this is material from the interior?
Previously Porco has said that the rotational tortion is not enough to maintain a liquid ocean core on a moon the size of enceladus. The information we need to solve this – is this geyser shooting out salt water – is withheld.

Even if the orbit input wouldn’t be enough in a static situation, there could be periods were orbital dynamics heat the moon to liquid reservoirs.

But as a matter of fact, IIRC newer models shows how a liquid layer sustain prolonged heating.

Is this geyser indicating liquid water? Theres two predictions here; 180 K is enough to sustain ammonia/water (partial) liquid formation as well as brines AFAIU. As a matter of fact, measurements of salts have been published. (Not withheld, why would they be, except in the minds of conspirationists – a conspiracy, always the least likely possibility of explanation by many orders of magnitude.)

How do you know that this is material from the interior?
Previously Porco has said that the rotational tortion is not enough to maintain a liquid ocean core on a moon the size of enceladus. The information we need to solve this – is this geyser shooting out salt water – is withheld.

“Enceladus has a reflectivity of nearly 100%, meaning it reflects nearly all the light hitting it, while Saturn only reflects 30-50% of the light that hits it (depending on how you measure it).

How does this compare with our Moon?
”

Our moon’s reflectivity varies from 6% at the darkest regions to 30% at the brightest regions.

Can’t say how much brighter that would make Enceladus in our skies. I’m guessing brighter than Earth would appear from the moon.

Of course, if Enceladus was orbiting Earth, I think it would melt.

Beautiful!

Clearly, these “geysers” you speak of are in fact the orbital maneuvering engines caught in the act of firing. NASA is hiding the truth, most likely in a hermetically sealed mayonnaise jar in Hangar 18.

No, no, its in area 52 – or was it area 53 or 51 or even area 25 instead?

@ 9. Jason Perry: Here’s a very big THANKYOU from me to you and the rest of the Cassini team – you guys are awesome & continually show us us some truly wonderful breathtaking things. Your work is very much appreciated.

Must be great to do that for a living. I just wish I had your job!

Enceladus has a reflectivity of nearly 100%, meaning it reflects nearly all the light hitting it, while Saturn only reflects 30-50% of the light that hits it (depending on how you measure it).

How does this compare with our Moon?

I take it Enceladus is much more reflective and brighter – one of the brightest & most reflective in our solar system?

How bright would Enceladus be if it were orbiting Earth insteadof our Moon?

As in life, sometimes what you see depends on how you look.

So very true.

J/P=?

Welp, I know what my new laptop image background is…..