Could Radioactivity Make Otherwise Frozen Planets Habitable? (sciencemag.org) 26
sciencehabit writes: Not too close, but not too far. That's long been the rule describing how distant a planet should be from its star in order to sustain life. But a new study challenges that adage: A planet can maintain water and other liquids on its surface if it's heated, not by starlight, but by radioactive decay, researchers calculate. That opens up the possibility for many planets — even free-floating worlds untethered to stars — to host life, they speculate.
Yes, Friend Giskard. (Score:4, Informative)
It very well could. Old Earth is hot on the inside mostly because of radioactive decay.
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Only 0.03% of earth's surface heat comes from the core. The other 99.97% comes from the sun.
If the sun disappeared, the heat from the core would be enough to warm the earth to 40K. Nitrogen would be frozen solid. The atmosphere would be hydrogen, helium, and neon.
There could be life deep underground or in deep ocean vents, but nothing on the surface.
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From what I've understood there's a fairly strong relationship between half-life and energy dissipated.
1 kg U-238 = 2.5*10^24 atoms
1 atom will dissipate 4.2 MeV directly and 51.77 MeV totally before it's stable radium.
0.5 * 2.5*10^24 atoms * 51.77 MeV = 1.05*10^13 J
half life = 4.5*10^9*365*24*60*60 = 1.42*10^17 s
1.05*10^13 J / 1.42*10^17 s = 7.4*10^-5 W
So if you had a thousand tons (10^6 kg) of U-238, you could produce 74W by radioactive decay. Fantastic.
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And we're constantly told that a 0.01% change in the atmosphere is going to cook the Earth
Who has been telling you that a 0.01% change of uranium is going to "cook the Earth"?
so why not a factor of 3000
Because that's not how the universe works. Really heavy elements are rare.
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I never said that change for uranium - because that's not part of the atmosphere. What we ARE told is that moving from 280 ppm to 350 ppm of CO2 (a change of 70 ppm - a little less than 0.01%) is an irreparable, irreversible change in our environment leading to the ending of humanity. So if the thermal flux from that tiny level change in the atm is a disaster, why not 3000 times that from an actual heat-producing element (rather than a partial heat-trapping compound)?
Oh, and U-238 isn't that "rare". Ther
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280 changing to 350. That's a 25% increase.
You don't want a 25% payrise because it's only
You'd hardly notice it would you.
Re: Yes, Friend Giskard. (Score:2)
You probably wouldn't have surface dwellers in that case unless they learned how to tap into their planet's core. Even on earth, if we got flung to the outskirts of our own galaxy by some event, microbial life could continue to live in the soil and near places like Hawaii and other vents in the ocean. Sure the top layers of the ocean would freeze over like Europa but seismic activity provides sufficient energy for organisms.
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We still don't know where live arose on Earth, underground is one of the possibilities.
Re:Yes, Friend Giskard. (Score:5, Informative)
It very well could. Old Earth is hot on the inside mostly because of radioactive decay.
Not mostly only about half if of the earth internal heat is generated by radioactive decay.
http://physicsworld.com/cws/ar... [physicsworld.com]
The other half comes is left over from energy resulting from planet formation.
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To quote your own link...
What is not clear, however, is how much of this heat is primordial – left over from the formation of the Earth – and how much is generated by radioactive decay.
And the research they quote doesn't make it any more clear.
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And the research they quote doesn't make it any more clear.
This is easily Googled. A new study reveals that only about half of our planet's internal heat stems from natural radioactivity. The rest is primordial heat left over from when Earth first coalesced from a hot ball of gas, dust, and other material. [sciencemag.org]
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When I see "used geoneutrinos" in an article, I tend to immediately classify the "study" as a speculation, sorry. I understand that Japan has invested heavily in the Kamiokande detectors and are trying to milk them for what they are worth, but it is a stretch to call making conclusions from a few events per day a stretch.
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All of the heat appearing at sub-sea ridges, which have rich biological communities, and volcanic vents, are from internal heat alone - none comes from the Sun. Plate tectonics is driven entirely by internal heat. Many recent theories on the origin of life think that geothermal vents are the most likely origins, and chemosynthetic life -- which uses no solar energy at all - is among the most ancient classes of organisms.
There is considerable reason to think that life commonly arises in planets (not "on") wi
Wait a second... (Score:2)
Let's do radiation at 1580 KHz... that's a good AM, wait that's heat!
Heat! The perfect radiation frequency for plants....
Click baity scientists say... (Score:2)
Could also be the other way 'round (Score:2)
I got this directly from a Powerplant. (Kraftwerk)
Tschernobyl, Harrisburgh
Sellafield, Hiroshima
Tschernobyl, Harrisburgh
Sellafield, Hiroshima
Stop radioactivity
Is in the air for you and me
Stop radioactivity
Discovered by Madame Curie
Chain reaction and mutation
Contaminated population
Stop radioactivity
Is in the air for you and me
Radioactivity
Radioactivity
Tschernobyl, Harrisburgh
Sellafield, Hiroshima
Tschernobyl, Harrisburgh
Sellafield, Hiroshima
Stop radioactivity
Is in the air for you and me
Stop radioactivity
Discov
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Probably how life started here, too (Score:2)
It could easily be that the first life here on earth developed from interesting organic slimes "feeding" off of warm, chemically rich flows from underwater volcanic vents and similar.
If the question could be definitively answered, I would bet a large amount of money that gentler versions of these vents were the creche for life as we know it on earth, and they are radioactive decay driven ecosystems, not sunlight driven.
I know it is speculative, but, to my mind, the question is going to be whether anything m
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I know it is speculative, but, to my mind, the question is going to be whether anything more interesting than a slime or flat worm is to be found on other planets. I am thinking simple life is common.
If we find a flatworm, we've found complex life (and probably a whole ecosystem of it). Simple (as in unicellular and slimes) life seems likely - it appeared on Earth almost as soon as we had oceans. Multicellular life took an extra 2.5 billion years to pop up.
Nuke it from orbit (Score:1)
I wonder about the likelihood (Score:2)
Let me restate that clearer... (Score:2)
Not radiation... we are looking for a place to ship our plastic. Our plastic.
Sorry about the error.