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Fraser
2007-Aug-29, 06:53 PM
Many planetary scientists believe that Jupiter’s moon Europa is our solar system’s best contender to share Earth’s distinction of harboring life. ...

Read the full blog entry (http://www.universetoday.com/2007/08/29/a-submarine-for-europa/)

piersdad
2007-Aug-29, 09:21 PM
The submarine idea surfaced some time ago.
i was very interested in the concept.
the immense pressures could easily be contered by encasing all the internals with a solid medium and using only radio frequency energy to sense the surrounding area.
building it i the form of a large saucer would mean it would slowly decend to the bottom of any ocean and once on th esea floor perhaps some form of propulsion invented
a fasinating project

antoniseb
2007-Aug-29, 09:26 PM
We should build something like this eventually, but I think that the 15-20 years estimate is very optimistic. The thickness of the ice could be 20-50 km. I also doubt that a fuel cell could provide enough energy to melt through that much ice.

One other side note is that such a mission would probably need a surface probe that would feed be at the other end of a fiber optic cable, since the ice is likely a good conductor of electricity, and therefore opaque to radio.

tony873004
2007-Aug-29, 09:40 PM
This internal warmth comes from tidal heating caused by the gravitational forces of Jupiter and Jupiters other moons which pull Europas interior in different directions
I believe it's just from Jupiter's gravity, and not the other moons. Their tidal forces are magnitudes smaller than Jupiter's.

But the other moons are necessary. Without them, and the 1:2:3 resonance of Io, Europa, and Ganymede, the orbit of Europa would circularize, and there would be no more tides. Since Europa is tidally locked to Jupiter, it doesn't experience tides as we're used to them, where the Earth rotates under the Moon. It's simply the difference in Jupiter's gravity between perijove and apjove in Europa's nearly-round orbit.

Kelfazin
2007-Aug-29, 09:43 PM
At Spacefest a couple weeks ago I had the pleasure of eating dinner with Dr. Bruce Betts, Director of Projects for the Planetary Society, and we spoke about this very idea. He said there is a planned mission to Europa, but it's only an orbiter. They are thinking, a little bit, about the submarine, but the technical difficulties are astounding at this point. It's not just landing on Europa that's the problem, its living in the radiation environment, finding a way to tunnel through the ice, and, most importantly, finding a way to send a signal back up through many kilometers of ice to be transmitted to Earth. He would love to be involved in the program, but doesn't see it happening anytime soon.

Procyan
2007-Aug-30, 01:00 AM
This is my first post. I hope it doesn't come off as a rant. Nothing lathers me up like politics running rough over science. Here again we see Europa (btw is a naked eye sighting of Galilean moons possible? I swear i've seen at least 2 of them unaided at early evening) as a highly ranked science goal lost to Man in Space. Its a money-suck & for what reason? I won't bore with all the arguments, thats all been done. Besides, logic won't work with Bush or whats-his-name, Gryphon.

But the following here, and Dr Pamela Gay and slakers and skeptics and many others online, is so immense. So dedicated to purpose.. Can we not, are we not compelled to organize and fight this mindless rodeo. Or is this being done and I've just missed it? I would like to join the fray!! :mad:

***Warning- rant alert***

OK, i'm better now. I forgot the details but some years ago there were blurbs about microbial-oid spectral signatures from that ruddy brown ice. Its fun to imagine some red-algea-ish bugs basking in reflected light from Jupiter, just waiting for the next warm bath from below. And where is that oxygen coming from? Darn, we're not getting any younger. What's it going to take to get that sub (sans parachute!) on its way??

Kelfazin
2007-Aug-30, 01:46 AM
You can't blame Mike Griffin for making the cuts he's had to make. He's a good administrator doing his best to adhere to the commands given him by the president. The fact of the matter is, Bush gave him the order to proceed with the VSE mission, and then congress failed to approve the budget increase NASA requested to fulfill that order. So now Griffin is required, as the man in charge of a government office, to fulfill the order regardless. The money has to come from somewhere, so science missions are cut off or pushed out to later dates. The problem isn't with Griffin, it's with the PoTUS and Congress.

Procyan
2007-Aug-30, 02:13 AM
OK, apologies re: Mike Griffin. Its not where I wanted to go. Shouldn't have said any names really. But I sense there is consensus around bang for the buck and, without wishing to rehash some very old arguments, robots work better than people, you know, in a vacuum.

I've sent my views to various gov/NASA agencies. I just thought whats next? How can the push be made to rein in any president giving over to Kennedy-esk proclamation? Its not just the Europa mission. Lots of good science has already been displaced by this bad decision. Not so?

GOURDHEAD
2007-Aug-30, 02:33 AM
In other threads I have argued in favor of placing power beam generators in polar orbit about the sun inside the orbit of Mercury. These beam generators would be capable of delivering on the order of 10^18 or so watts. With a power receiver in orbit about Europa capable of receiving and regenerating and redirecting the beam, we could melt a rather large access hole through the ice shell and maintain its contents in a liquid water state making it easy for a "diving bell" type submarine to enter and trail a cable capable of transmitting data to an orbiting relay station thence to Earth. The caution is that living organisms could have generated gaseous substances that may have formed/filled space between the liquid water and the ice shell such that when the hole is melted in the ice shell, an explosive type eruption may occur causing a mountain of ice to form on Europa's surface around the access hole.

Such a project would require an infrastructure that takes two or three hundred years and a few terradollars to complete.

antoniseb
2007-Aug-30, 11:49 AM
What's it going to take to get that sub (sans parachute!) on its way?

I'm pretty strongly in the robotic exploration over manned exploration camp, but in my opinion doing what it would take to accelerate the launch date of a Europa submarine project to sometime before 2025 is also a waste. There are many cheaper (but still pricey) projects that will yield more immediately useful results. If Europa has algae, it isn't going anywhere. Yes we'll all be pretty old in 2060, or whenever this thing gets sent, but we need to develop some tools that we don't have yet if this is going to work.

John Mendenhall
2007-Aug-30, 02:57 PM
(btw is a naked eye sighting of Galilean moons possible? I swear i've seen at least 2 of them unaided at early evening)



It's at the limits of unaided vision for those with good eyes, but probably possible. My oldest son had very sharp eyes as a youngster; I one evening thought to ask him "Can you see any little dots near that bright star? And if you can, which side are they on?" A quick trip inside the house for the current issue of S&T revealed that he had the three moons then visible in their correct locations. But it takes good eyes. He could do crescent Venus, also (you check to see which way the horns are pointing), but he said it was really difficult.

Procyan
2007-Aug-30, 10:25 PM
It's at the limits of unaided vision for those with good eyes, but probably possible. My oldest son had very sharp eyes as a youngster; I one evening thought to ask him "Can you see any little dots near that bright star? And if you can, which side are they on?" A quick trip inside the house for the current issue of S&T revealed that he had the three moons then visible in their correct locations. But it takes good eyes. He could do crescent Venus, also (you check to see which way the horns are pointing), but he said it was really difficult.

Thats encouraging! I'm 53 & far sighted, but at least i've still got good looks at a distance!:lol: Also thought I could see a cresent Venus, but its really subtle. Thanks. I havent googled this, but is there a site that udates the current configurations of the jupiter system? whats the best way to check that?

Regarding a Europa mission, the argument I would propose is not "whats the best plan?" (see Space Exploration/ Really cool "cryobot" for Europa) , I'd leave that to the brainiacs. I do argue that it is a mistake to subjugate good science to bad politics. I wonder if this strangely beautiful ocean planet could evoke dissent in the public mind. A probe to a youthful wet and wild Europa Vs. people to dusty old Moon?

Am I wrong to assume geeks & scientists agree on this (any?) point? Who among my generation can watch those ancient apollo clips without misting up. I love the whole idea of moving bits of humanity into the solar system and beyond. To be fair, I guess it all comes down to whats best for the USA. What do the people want to do? "I'm paying for this launch pad Mister!"

Is this a subject for a new discussion? I really don't wish to reargue the issue man vs. robots. Rather, I wonder, if there is a consensus, then what concrete actions might be taken.

I've lurked here for years. Impressive collection of talented folks hang out here. But we are all very busy too. Theres the rub.

JESMKS
2007-Aug-31, 12:01 AM
Before we spend a lot of money designing a submarine for Europa, maybe we should do a little prior investigation. Some radioactive wastes stay thermally hot for many years. Possibly this property could be used in the design of a relatively inexpensive probe to determine the thickness of the ice and the depth of the underlying water. The probe could be designed to melt its way through the ice with a tether to he surface to relay data back to Earth.The thickness of the ice could be determine by a sudden change in outspooling of the tether, and the depth of the underlying water by the end of outspooling. The probe could also make some simple test on water quality. This information would help in the design and suscessful deployment of a submarine.

WaxRubiks
2007-Aug-31, 10:12 AM
I would think that breaking up the ice would be more energy efficient. ie drilling down.

piersdad
2007-Sep-01, 06:28 AM
whatever the research into a possible probe it will easily bring technical innovations available to every day people here.
i remember a friend who did the initial reserch and development on superglue for the echo 1 satelite.
his tool was a early computor with a massive 1 meg hard drive and had to stop the main programme to do gosubs etc.
from this research funded by nasa we have the hard glossy surface on our cars today.
so what ever is developed for any of these exotic projects there is always a trade off that benifits the rest of the world.