Enceladus has a global underground ocean!

[Frida Space]

According to a new research based on Cassini data, what we thought was a regional underground sea deep inside Enceladus' south pole (i.e. where tiger stripes and geyser curtains are found) turns out to be a vast, global underground ocean! This discovery is very important not only for Enceladus' biological potential, but also for all other icy moons in the solar system (Europa and the ice giants' satellites in primis), especially when you think that even a body as small as Enceladus somehow can mantain a liquid underground ocean. Where this heat comes from is still unknown; the authors of the study have speculated that the tidal stress Saturn exerts on Enceladus could be greater than thought.

Some important paragraphs from the press release, regarding how they arrived to this extraordinary conclusion:

Cassini scientists analyzed more than seven years' worth of images of Enceladus taken by the spacecraft, which has been orbiting Saturn since mid-2004. They carefully mapped the positions of features on Enceladus -- mostly craters -- across hundreds of images, in order to measure changes in the moon's rotation with extreme precision.

As a result, they found Enceladus has a tiny, but measurable wobble as it orbits Saturn. Because the icy moon is not perfectly spherical -- and because it goes slightly faster and slower during different portions of its orbit around Saturn -- the giant planet subtly rocks Enceladus back and forth as it rotates.

The team plugged their measurement of the wobble, called a libration, into different models for how Enceladus might be arranged on the inside, including ones in which the moon was frozen from surface to core.

By the way, here is a cool gif of Enceladus' rotation (from here, in Italian):

[Cydonian Monk]

Why yes. Yes it does. And previously confirmed organic molecules. So: Lots of Water. Lots of Heat. Known Carbon. Those three lead to a common fourth:

Moonshine!

Get your stills ready!

In all serious though, this announcement is a perfect example of why extended duration probe missions are critical. Had Cassini been dumped when its primary mission was over (ended in 2008?), we might not have had enough data to confirm this finding.

[AngelLestat]

Cool gif, but the title is not a news.. Is know since a lot.

You should retitle as "new evidences that confirm ocean in enceladus"

[Sylandro]

Sweet. I always thought that Enceledus had a pockets of pressurized water below it's surface, but not a global ocean.

It wouldn't surprise me if the next discovered global ocean below a moon's surface might be Callisto (albeit slushy), or Triton.

[LordFerret]

With the ice crust estimated to be 30 to 40 kilometers thick, we won't be visiting that ocean anytime soon. Very interesting though.

[baggers]

With the ice crust estimated to be 30 to 40 kilometers thick, we won't be visiting that ocean anytime soon. Very interesting though.

Sweet. I always thought that Enceledus had a pockets of pressurized water below it's surface, but not a global ocean.

I noticed that the Enceladus Ocean as a "relatively low pressure" ocean too:

http://www.space.com/28978-enceladus-europa-ganymede-alien-life.html

"A major difference between Enceladus and Ganymede is the difference of pressure at the base of the ocean," Tobie said. The pressure at the base of Enceladus' ocean is rather low, at 50 to 100 bar  or about 50 to 100 times the atmospheric pressure of Earth at sea level. This low pressure permits water from circulating in underlying porous rocks, thus helping to drive chemical reactions that could lead life to emerge.

In contrast, the pressure at the base of Ganymede's ocean is much higher  about 15,000 to 20,000 bar, Tobie said. Under such high pressure, not only is rock less porous, but water can form a kind of ice.

100 bar is the pressure of earth ocean @-1000m. Many fish and Shrimp live here. Some giants Squid too!

Edited September 16, 2015 by baggers

[Coyote27]

With the ice crust estimated to be 30 to 40 kilometers thick, we won't be visiting that ocean anytime soon. Very interesting though.

We could eventually melt our way through with an RTG type device, I'm sure. Just land a probe that stays hot and it'll sink into the ice little by little.

[ChrisSpace]

I thought we knew this ages ago. Am I missing something?

[baggers]

I thought we knew this ages ago. Am I missing something?

We knew the geyser, and water pocket.

What's new is the proof of a global ocean all over the core.

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We could eventually melt our way through with an RTG type device, I'm sure. Just land a probe that stays hot and it'll sink into the ice little by little.

And you could easy try it on earth.

But encelade has very low gravity.

[YNM]

Hmm... Well, I somehow can't access the page from mobile, but I'm quite interested in what kind of assumptions they made. Also, that means a whole retinue of new unique world - let's set our interplanetary camps there instead, shall we ?

[baggers]

We could eventually melt our way through with an RTG type device, I'm sure. Just land a probe that stays hot and it'll sink into the ice little by little.

https://en.wikipedia.org/wiki/Enceladus_Explorer

Melting probe. Already tested on swiss glacier:

[AngelLestat]

We knew the geyser, and water pocket.

Everybody knew about a global ocean underneath the ice. There was not enoght proof, but that explanation had a lot more possibilities to be true than just a water pocket, due how small enceladus is and knowing the source of that heat.

Melting probe. Already tested on swiss glacier:

https://upload.wikimedia.org/wikipedia/commons/thumb/9/91/IceMole1.JPG/800px-IceMole1.JPG

http://www.icarusinterstellar.org/wp-content/uploads/2014/04/fig-2.jpg

https://upload.wikimedia.org/wikipedia/commons/thumb/4/43/IceMole_in_action.JPG/450px-IceMole_in_action.JPG

https://upload.wikimedia.org/wikipedia/commons/thumb/7/75/IceMole_melting_channel.JPG/800px-IceMole_melting_channel.JPG

http://www.icarusinterstellar.org/wp-content/uploads/2014/04/fig-4.jpg

Nice, but I imagine that this test probe device is not RTG by the moment.

But if its mission is to take samples from the geiser, why they dont do it from the surface?

About a probe able to reach the ocean melting several km of ice, I think nuclear thermal is a best solution, they just need to find a good way to transmit info through the ice, which may not be difficult with the right wavelenght.

[LordFerret]

...

About a probe able to reach the ocean melting several km of ice, I think nuclear thermal is a best solution, they just need to find a good way to transmit info through the ice, which may not be difficult with the right wavelenght.

I've commented on this previously, in another thread somewhere here having to do with Europa; To use a probe as such with a wire, like a TOW missile, the wire going all the way back to the surface to a base station and data transmitted from there. Pretty much, just as pictured in the diagram.

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Thinking about it, looking at the image of the tube/tunnel created by that test probe... I wonder if they've ever looked into using the ice tunnel created by the probe as a microwave waveguide? Maybe data communication could be accomplished using microwave, beaming data back up through the tunnel. The walls of the tunnel appear smooth enough, and ice has very low bulk resistivity.

[AngelLestat]

This thing carries a cable because the energy source is in the rover.

But if your cable needs to go down until the ocean, that last layer will freeze which it will trap the cable, so the submarine can not go away, also not sure if you can sublime all the ice-water that you melt to produce the hole, after some km, some of that gas will be stick into the sides and maybe block the cable, gravity will keep the water molecules in the hole.

Also several km of cable will be very heavy and hard to handle without obstruction.

Maybe there is some kind of wavelenght to transmit that is not absorbed by the water, and you let the submarine free of cables that can be stuck in the hole.

[Motokid600]

It doesn't matter if the hole gets closed off I imagine. If you can run a wire down to the ocean you can have an antenna on the end of it in the water. Then the probe swims off and communicates with that.

Problem is... What are the chances of the ice moving and severing the wire?

[Kibble]

Probably most icy worlds in the outer Solar System have global underground oceans of molten water - the same way Earth has a global underground ocean of molten rock.

[AngelLestat]

It doesn't matter if the hole gets closed off I imagine. If you can run a wire down to the ocean you can have an antenna on the end of it in the water. Then the probe swims off and communicates with that.

Problem is... What are the chances of the ice moving and severing the wire?

That is a possibility, but you still need a way to get rid of all that ice you sublime (melt) before it block the cable above you.

It may be 2 ways to solve this:

1- you deploy the cable from the same submarine so you dont need to drag it from the rover (increase the side of the hole needed and the long of the probe)

2- you use another hose to vacuum clean all the ice you sublime, carrying the ice to the surface.

Risk: If there is ice movement your cable will be cut.

Another way to do it, is making a new hole with your laser transmiter from surface.

It needs to be a powerfull laser, the same heat will increase the pressure of the hole extracting all the ice from the hole, then the submarine needs to locate the laser hole and place a communication device in place that use the same laser as transmission.

A good way to test all these devices will be in the Vostok lake antarctica

[LordFerret]

Another thing to consider with this hole-boring submarine idea, is that once you drill though the crust you may very well encounter pressures the second your break though which would turn that hole into a geyser, turning that 'submarine' into a bullet shot from a cannon.

Maybe the thing to do would be to sit poised next to an existing geyser, and the moment it subsides drop the probe-sub in.

[Kryten]

Thinking about it, looking at the image of the tube/tunnel created by that test probe... I wonder if they've ever looked into using the ice tunnel created by the probe as a microwave waveguide? Maybe data communication could be accomplished using microwave, beaming data back up through the tunnel. The walls of the tunnel appear smooth enough, and ice has very low bulk resistivity.

If you're actually trying to reach multi-km depths, you will not end up with a tunnel. Even at Enceladus-level gravity, it'll have enough pressure to close up.

[LordFerret]

If you're actually trying to reach multi-km depths, you will not end up with a tunnel. Even at Enceladus-level gravity, it'll have enough pressure to close up.

Do you mean to imply it would close up immediately, or rather very quickly? I would imagine 'very quickly' being the case if the melt from the probe-sub wasn't evacuated somehow, that as it bore down there would be re-freezing taking place behind it. That being the case, maybe leaving a trailing wire during descent would be the more viable option?... the quick re-freezing encasing the wire, safely locking it in? The only issue then would be any shifting of the crust, I'd suppose.

[Kryten]

I don't mean freezing, I mean it'll collapse.

[baggers]

If you're actually trying to reach multi-km depths, you will not end up with a tunnel. Even at Enceladus-level gravity, it'll have enough pressure to close up.

Enceladus is something like 50-100 bars at the base of his ocean. Is that enough pressure to close up an ice tunnel?

[AngelLestat]

Another thing to consider with this hole-boring submarine idea, is that once you drill though the crust you may very well encounter pressures the second your break though which would turn that hole into a geyser, turning that 'submarine' into a bullet shot from a cannon..

That would be an epic failure for a billion type of mission

But fun to watch.

I guess there is no way to get around the cable method.

One way or another the hole will be seal-collapse-or shot the submarine out.

Even from the same melting ice that its sublime, the gravity will keep all the flozen vapor in the hole.

The only way is a wireless submarine.. You dont need to deal with any of those problems. The only problem is communication.

But I guess it may be a way to get around that problem.

Is a shame we dont have a neutrino antenna-emissor

Some ideas how it can be done without a cable?

Edited September 16, 2015 by AngelLestat

[baggers]

If a cable isn't enough, try 2 cables? The "a cable in a cable" thing: the first exterior cable is for reaching the ocean just before the geyser, seal the tunnel on it and open the cork.

The second slide in the first and is for submarine exploration.

[LordFerret]

Well, a smart autonomous sub could melt its way down, enter the ocean, swim around and collect data, and then melt its way back up and deliver that data. Yes? No?