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Melting Europa
amigoro writes "After having contaminated Earth's Oceans, it seems that there are plans to send a probe drilling through Europa's ice sheet and explore the purported ocean below the crust. The plan seems to be to find Life there. But I wonder how long the time lag will be between the probe finding life, and a leak in the radioactive heater wiping all of it out."
In all seriousness, why does it matter? This sounds like a lot of money to spend on a "maybe." I've wondered this for a while now, and I'd like to hear someone explain why this search for life is so crucial. I feel there might be better ways to spend the money, and better ways or opportunities to discover life on other planets/celestial bodies.
Cry me a river. As has been stated a million times before, you can't help but change any system you are observing by just observing it. Now, I understand this is a pretty severe violation of a system that has never been touched by anything human made, but you need to break some eggs to make pancakes.
If you are so worried about the possible life under the crust on Europa, why not think about Earth for a minute! With all those microscopic organisms you are killing by just breathing, you should be ashamed of yourself! (Thank you Mr. Breathed...)
I once dated someone who was fully against the exploration, or colonization, of Mars because she feared that we were given this planet and we've made a mess of it. She argued that we had no right to go to another planet that didn't belong to us and alter it in any substantial way. After a few somewhat lenghty discussions trying to pin down exactly what her issue was about, I discovered that the she felt that GOD had given us this planet and not Mars, hence we shouldn't mess up God's plans with Mars by stomping all over it with our oversized space boots.
I didn't agree. I've got a feeling this argument, while maybe not coming from a religious perspective, has a lot of the same concepts built in. Guess what, we humans, as a race, own everything in the solar system. It is ours to do with as we see fit... other planets are being wasted until we make full use of them for humanity as a whole. Until and unless I'm shown proof of life on another planet, and it would probably have to be a somewhat substantially high order of life, I'm going to argue that it's our position to decide the destiny of every bit of metal, gas and rock that's floating in orbit around our sun.
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RumorsDaily
If there is anything down there on Europa, it will probably eat the nuclear leakage for dinner and come back for seconds.
Not that seriously. The first Apollo mission found the moon to be sterile, but later Apollo missions found strep bacteria from previous missions.
Bacterial contamination is a real danger to life and to accurate science on Europa and lake Vostok. It is extremely difficult to keep a robotic probe from carrying contamination since modern electronics can't take the extreme heat needed to kill resilient strains (which since they're so resilient would make them even more harmful). Scientists have been putting more effort into trying to figure out how to explore Europa without contamination, but are having a tough time coming up with a solution.
I dunno, wouldn't sheets of ice have the happy side effect of absorbing/sheilding large amounts of radiation?
As a graduate student in astrophysics (not planetary geology, which this would fall under), I think this is an overall good idea. (Agreed, the poster sounds a tad biased.)
There are a few points which I would like clarified by someone who is perhaps knowledgeable. For one, landing a spacecraft on Europa, where we have little knowledge of its atmospheric conditions, will be a formidable challenge. (We've lost many Mars-intended missions due to that.) How can we plan for that?
Secondly, I don't think it's known how deep the ice goes? Is there a plan for if the ice is a foot thick? How about 10 feet? How about 1000?
Next, can we still transmit a signal back if we have to take a probe that far underwater?
Notwithstanding a Europan shark eating the probe, I think there are some serious scientific reasons to be concerned about the search for life on one of the solar system's most likely candidates -- and we should ask ourselves if we're taking the best approach for a multi-hundred-million dollar mission?
Except any life on Europa will have evolved away from that radiation since its protected by almost 20km of ice.
The real threat of any contamination from a probe is not so much from radiation as from heavy metals leaching into the environment, but then if the floor of the Europan ocean is anything like the black smokers of Earth's oceans any life should be used to heavy metals.
Best wishes,
Mike.
Sooner or later, the radiation will work its way in.
The neutrons are absorbed by the top molecular layer. Eventually they'll re-radiate (nuclear shielding material becomes radioactive itself eventually), and the next layer will become active, and so on, and so on.
While it's true that some bacteria would be transported to Europa, how much? If Europa is cold enough to freeze water, then it's cold enough to keep bacteria GROWTH to a standstill, right? The bacteria would just lay dormant, wouldn't it?
Perhaps there's some biology nerds out there who can offer us some insight.
Stack overflow: pid 352258, proc httpd, addr 0x11f7ffff0, pc 0x12000195c Segmentation fault (core dumped)
Biogenic assumes that living things die, are deeply buried in the crust, rot, and in so doing create various hydrocarbons. Abiogenic assumes that primordial material from the creation of the planet are cooked and rise into the crust. This theory posits that biological microfossils found in petroleum are leeched from the crust by the flow, rather than being one of the byproducts of biogenic rot.
Kooks like J. F. Kenney grasp at old research by a few Soviet geologist to claim that abiogenic reserves are being constantly replenished more quickly than even our current rate of extraction(1).
The vast majority of geologists would say that while research confirms that abiogenic formation of gaseous alkanes can take place in the Earth's crust, a comparison with the isotopic signatures of economically important gas reservoirs around the world suggests that abiogenic production is not a globally significant source of hydrocarbons (2).
Luke, help me take this mask off
The remark about the radiation reminded me of the recent story about the Lunokhod vehicles (the Russian moon rovers). I found the use of Polonium-210 for heating the rovers very interesting.
Some intersting stuff about Polonium-210 on Wikipedia:
"half a gram quickly reaching a temperature above 750 K" (476.85C)
"This isotope is an alpha emitter that has a half-life of 138.39 days."
"...nearly all alpha radiation can be easily stopped by ordinary containers and upon hitting its surface releases its energy..."
BTW Did anyone else see the picture of Susi the "melting probe"? lmao I wonder where they got the idea for the design of that! Does it vibrate too?
As somebody who dived there in the past 10 years I can attest to the incredible multitude of life that is there now. Every square inch of "land" above sea level is covered by life, and what is under water is literally choked with plants and animals. It is amazing to behold, and it gives you an idea of just how adaptable and tough nature is.
This isn't news.
... you're right. That's not news. People have been fearing the words "nuclear", "reaction", "radioactive", and "atomic" for many years now. Any damage that might be done to the surrounding area because of a failure would be absolutely insignificant on a planetary, or even regional, scale. Just because the media have taught us to fear and hate anything with the word "nuclear" in it is no reason not to trust the technology.
What do you mean, this isn't news? I've been waiting for someone to develop serious technology for a landing on Europa for quite some time now. Given that Europa is one big ocean and is the single most likely place in our solar system to find life (present planet excepted, of course) it's about time we thought about going there.
Now, the hippie spin on the word "radioactive"
NASA has been using Radioisotope Thermoelectric Generators (RTGs) for decades on planetary probes and manned missions. The basic premise is this: a container holds some radioactive heavy metal, such as plutonium. Because the metal is decaying, it generates a bunch of heat. That heat is used with thermoelectric generators to create electricity, and the leftover heat (since the reaction is not not that efficient) is used in other ways, like keeping the astronauts warm. But here's the kicker: an RTG has never, ever failed on a space mission. Not once. It's been flown hundreds of times. (Missions using RTGs have failed, but the RTGs themselves performed flawlessly every time.) Just because it's "nuclear" doesn't mean it's Chernobyl.
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Hippy
Maybe not a hippy, but what in the world was the point of mentioning contaminated Oceans [sic]?
And why is that word capitalized?
Java is the blue pill
Choose the red pill
BZZZT! Wrong! Thanks for playing. If you had read the Guardian article you would have found out that:
"In November 1969, Apollo 12 landed just 170 yards from Surveyor 3, a robotic craft that had achieved the first soft lunar landing by an American probe two-and-a-half years before."
Parts of the craft were recovered in sterile conditions and were studied back on Earth. Scientists found "between 50 and 100 living micro-organisms were extracted from the polyurethane foam insulation that covered its interior circuit boards... The astronauts ferried back the contents of a sneeze by a worker assembling Surveyor 3."
These were organisms that had been brought to the moon by the Surveyor 3 probe, not the astronauts. Not only that but they survived for years on the surface of the moon. So no, it is not easy to keep a robotic probe from having bacteria.
"It is difficult to get a man to understand something when his salary depends upon his not understanding it."