Searching For Ocean Life On Another World 49
An anonymous reader writes: National Geographic has a detailed article about efforts underway to search for life in the oceans of Europa, which are buried beneath miles of ice. A first mission would have a spacecraft orbit just 16 miles over the moon's surface, analyzing the material ejected from the moon, measuring salinity, and sniffing out its chemical makeup. A later mission would then deploy a rover. But unlike the rovers we've built so far, this one would be designed to go underwater and navigate using the bottom surface of the ice over the oceans. An early design was just tested successfully underneath the ice in Alaska. "[It] crawls along under a foot of ice, its built-in buoyancy keeping it firmly pressed against the frozen subsurface, sensors measuring the temperature, salinity, pH, and other characteristics of the water."
Astronomers and astrobiologists are hopeful that these missions will provide definitive evidence of life on other worlds. "Europa certainly seems to have the basic ingredients for life. Liquid water is abundant, and the ocean floor may also have hydrothermal vents, similar to Earth's, that could provide nutrients for any life that might exist there. Up at the surface, comets periodically crash into Europa, depositing organic chemicals that might also serve as the building blocks of life. Particles from Jupiter's radiation belts split apart the hydrogen and oxygen that makes up the ice, forming a whole suite of molecules that living organisms could use to metabolize chemical nutrients from the vents."
Astronomers and astrobiologists are hopeful that these missions will provide definitive evidence of life on other worlds. "Europa certainly seems to have the basic ingredients for life. Liquid water is abundant, and the ocean floor may also have hydrothermal vents, similar to Earth's, that could provide nutrients for any life that might exist there. Up at the surface, comets periodically crash into Europa, depositing organic chemicals that might also serve as the building blocks of life. Particles from Jupiter's radiation belts split apart the hydrogen and oxygen that makes up the ice, forming a whole suite of molecules that living organisms could use to metabolize chemical nutrients from the vents."
Obligatory (Score:4, Interesting)
But seriously, cool stuff.
How do they plan to send communications back to earth from under the ice? I assume they will have a rover on the surface that will communicate with the diver and possibly a satellite, that will communicate with us.
Re: (Score:3, Interesting)
I was wondering the same thing (about communications). Depending on how many miles of ice we're talking about would determine if any form of tethered array could be used (i.e. - "diver" drills / melts into ice for 1 or 2 miles, leaving along a cord which is connected to an uplink sat system which communicates to whatever it floating in orbit, etc.) Not sure what kind of materials we have that could ensure that the cord wouldn't break but I would think that even 2 miles worth of cord would be an awful lot to
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If it's a few miles, you could communicate by sonar. One part of the device goes under the ice and vibrates while the other sits on top and listens.
The bandwidth would probably be awful but at least you could get a few bits through.
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The predominant theory at present is that it's somewhere in the ballpark of 20km. Some argue for only a few kilometers, but that's a minority view. And it's even worse when you're at the bottom, the sea is expected to be about 100km deep.
How do you communicate through 20km of ice plus up to 100km of water?The total absorption in question here is just massive. Earthquake-strength sonar? ELF waves with a dozens-of-kilometers-long antenna? Cycling your nuclear reactor on and off and having a super-sensitive n
Re: (Score:2)
100km of water is nothing for SONAR, especially since Europa probably lacks a lot of noise pollution sources that exist in earths oceans. Getting equipment and a power source capable of putting out enough dB would be difficult though. Also, that 20km of Ice would likely act as a mirror and just reflect any transmissions back downward. ELF SONAR as you mentioned might actually get through the ice, but probably with a large loss in signal strength.
Though putting a receiver below the ice and a transmitte
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Stone Aerospace has some elaborate plans [csmonitor.com]:
Contamination (Score:1)
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earth bugs would die from the intense radiation around Jupiter.
Re:Contamination (Score:5, Informative)
Oh, really? [wikipedia.org]
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That's not what NASA Planetary Protection thinks and, at least for US space probes, that's what counts.
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Yet extraordinarily tenacious and perverse.
Re:Contamination (Score:5, Interesting)
I wonder what they are doing to guard against contamination from Earth bugs. IIRC, the Mars rovers showed up as dirty.
Lots. Europa is in the elite Category III / IV of planetary protection [nasa.gov], along with Mars and Enceladus,
The Europa probe is likely to get a little less scrubbing, significantly less than an Europan orbiter, but more than the Juno spacecraft [nasa.gov], as, although it will be in a Jovian orbit going near Europa, it can be placed in a "safe" orbit away from Europa at the end of the mission. But, Europa orbiters and landers will get the full treatment.
By the way, even if Mars landers had some bugs, they were sterilized, which undoubtedly greatly reduced the total bio-loading, Just because you didn't wash your hands once before dinner doesn't mean you should stop washing them altogether subsequently.
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"The Europa probe is likely ..."
That should be
"The Europa clipper probe is likely ..."
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I was not aware that the bible had anything whatsoever to say about life elsewhere in the universe - in fact I seem to recall that it has nothing much to say about anything else in the universe even existing. Almost as though it was written for (or by) humans who had no knowledge of, or use for, anything not directly related to their home planet.
Europa Clipper (Score:3)
Actually, the first mission dedicated to Europa will be the Europa clipper [nasa.gov], focused on Europa, but not in Europa orbit. The radiation near Europa is so intense (even for machines) that dipping in and out of the field in an inclined Jovian orbit will save about a billion dollars over going into a Europan orbit.
subject (Score:2)
ok, so if we're pretty sure there's no "intelligent" life capable of nuking us...
How about we just send a reactor there... land it on the ice, and let it do its thing until it melts its way through? Is it possible to have a controlled reaction long enough to get through the ice... the spread the fissile material out in some way and have it seal itself tight for the next 10k years?
Once through, the reactor should provide plenty of power to get a signal through the ice I would think. Also, the radiation from
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Water ice floats (Score:1)
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terrible joke, and you're a terrible person for saying it. Die in a fire.
Wrong! The Clipper will not orbit Europa (Score:2)
Sample the plumes; don't drill (Score:2)
Punching through ice isn't drilling. (Score:2)
Watch Europa Report first... (Score:1)
will provide tips on what not to do...
http://www.imdb.com/title/tt20... [imdb.com]
Re: (Score:1)
Europa, the next big challenge (Score:3)
Slush (Score:2)
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Well, think of how water freezes on a cold lake. There's a sharp divide because water isn't still. Heat being generated at the core of the moon would ensure warmer fluid would move towards the ice barrier, and colder fluid would move towards the core. This cycle tends to keep 'slush' from forming.
Interesting...didn't think about that. I suppose what got me thinking of the slush idea was the sheer scale of the environment compared to ours here; the entire moon is frozen. Here's some info on theories about Europa's oceans: http://en.wikipedia.org/wiki/E... [wikipedia.org]
And possibly evidence of slush, depending on how you interpret the word "ductile":
...it is predicted that the outer crust of solid ice is approximately 10–30 km (6–19 mi) thick, including a ductile "warm ice" layer...
Guess there's only one way to find out. I personally can't wait!
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Indeed, and I'm unclear as to why you'd want to crawl along the underside of the ice in any case when you can just... swim.