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Thread: If the outer molten core of earth cools enough to solidify,

  1. #1 If the outer molten core of earth cools enough to solidify, 
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    If the outer molten core of earth cools enough to solidify, we will lose our atmosphere. It has happened to Mars and Venus I believe. What is the probability that it will happen to earth. This would end most life on earth. Is this to be our ultimate fate? Thanks for comments. Joe L. Ogan


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  3. #2 Re: If the outer molten core of earth cools enough to solidi 
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    Quote Originally Posted by Joe L. Ogan
    If the outer molten core of earth cools enough to solidify, we will lose our atmosphere.
    No, Joe, but your magnetic compass will be useless ...

    It has happened to Mars -
    only partly ... Mars lost most of its atmosphere because of its low relative mass and strategically awkward position (close enough to the sun to lose atmosphere to solar wind etc - the lack of a magnetic field is a contributor here - and close enough to Jupiter and the asteroid belt to cop a real belting) ...

    - and Venus I believe...
    hardly - the atmosphere of Venus is ~90 times denser than that of the Earth ...

    ... What is the probability that it will happen to earth. This would end most life on earth. Is this to be our ultimate fate? ...
    only if the red nova phase of the sun doesn't cook the surface first ...


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    Mars and Venus both have atmospheres.

    The Earth has existed in its present state for billions of years. I'm not sure why it would suddenly take it into its head to cool its outer core.
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    No, how did you come up with this, mars has an atmosphere, just thinner and more smoother, earths is a little thicker, and venus has sulpheric acid making it unbreathable, but planets cannot be tampered with.
    the more science you know, the less crap you get.
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    Not really on topic, but would anybody care to speculate on Europa's core, and state? Observably it's hot enough to boil water at whatever pressure is down there. This seems awfully hot given Europa's puny mass, lack of atmospheric blanket, and distance from the sun.
    A pong by any other name is still a pong. -williampinn
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    Quote Originally Posted by Pong
    Not really on topic, but would anybody care to speculate on Europa's core, and state? Observably it's hot enough to boil water at whatever pressure is down there. This seems awfully hot given Europa's puny mass, lack of atmospheric blanket, and distance from the sun.
    Not much speculation needed here. Europa is subject to tidal forces caused by Jupiter's strong gravitational field. These forces lead to a constant flexing of Europa's surface that produces the necesssary heat.
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    So it's heated most where it flexes most: in the frozen crust? And heat rises in Europa too. Then I reckon those geysers are very cold, and liquid only due to pressure... hm... still weird... Why wouldn't water absorb pressure when it melts?

    If it's gradually freezing, that must build pressure inside.
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    Quote Originally Posted by Pong
    So it's heated most where it flexes most: in the frozen crust?
    yes ... and no ...
    tidal forces relate to the difference between the nearest and furthest point of a body being influenced by variations in gravitational attraction (for want of a better term) - and the greatest difference in a small airless world would be opposite points of the surface ...

    however - ((don't you hate those?)) -
    the response to tidal forces is greater in a fluid than in a solid (ocean tides are larger than land tides on Earth, for instance), so in the case of a subsurface liquid, it would tend to bulge (flex) more than the overlying solid surface ...

    And heat rises in Europa too. Then I reckon those geysers are very cold, and liquid only due to pressure... hm... still weird... Why wouldn't water absorb pressure when it melts?

    If it's gradually freezing, that must build pressure inside.
    ahh, but building pressure in water doesn't always mean freezing - you might have heard about the lakes underneath glaciers in Antactica? - water is such a fun compound with all sorts of phase states depending upon the pressure and temperature ... so that a subsurface Europan ocean could be sandwiched between two different forms of ice ...

    this page might help:

    from - Water Phase Diagram
    The density of liquid water increases with increase in pressure...

    Hexagonal ice is less dense than liquid water whereas the other ices found in equilibrium with water are all denser with phase changes occurring on the approach of the liquid and solid densities.
    Nature abhors perfection; cats abhor a vacuum.

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    Thanks, good info.

    What I meant by if gradually freezing, was if Europa's heat loss to space exceeds tidal heating. Has Europa already reached equilibrium?

    Besides some weird scenarios, Europa's surface would have begun to freeze some time in the past, at low pressure. Then you have a freezing front descending coreward, encountering greater pressure (or maybe no...? :? ) as it progresses. Anyway it seems possible that at some point that front would reach a depth and/or tidal wave pressure where it's forming hex ice. This alone could drive volcanoes, especially with crust weakened by tides. So volcanoes relieve pressure as it occurs, with new ice always being hexagonal, due to positive feedback. Does this perpetuate a rather Earthlike environment just under the crust?
    A pong by any other name is still a pong. -williampinn
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    Quote Originally Posted by Pong
    Thanks, good info.

    What I meant by if gradually freezing, was if Europa's heat loss to space exceeds tidal heating. Has Europa already reached equilibrium?
    I'd be surprised if it hasn't bled off all of its initial heat, and that tidal energy dominates its current internal heat budget ...

    Besides some weird scenarios, Europa's surface would have begun to freeze some time in the past, at low pressure. Then you have a freezing front descending coreward, encountering greater pressure (or maybe no...? :? ) as it progresses. Anyway it seems possible that at some point that front would reach a depth and/or tidal wave pressure where it's forming hex ice. This alone could drive volcanoes, especially with crust weakened by tides. So volcanoes relieve pressure as it occurs, with new ice always being hexagonal, due to positive feedback. Does this perpetuate a rather Earthlike environment just under the crust?
    I think it's safe to say that, even in Europa, pressure increases with depth ...

    As I understand it, Europa's surface is more like sea ice - rather than volcanoes (like Io), water wells up through cracks and rapidly freezes - I've not heard of any geysers (like Triton), but I'm not up with the latest news on Europa ...

    Not sure what you mean by "Earthlike environment" - Earth hasn't got anything like oceans approaching 100km depth (if the guesstimates are anything to go by) ... the closest potential analogue would be the subglacial lakes of Antarctica, blended somehow with the abyssal methane seeps ...

    there is some thought that immediately below the ice surface (estimated up to 10km thick) lies a "slush zone" - dense cold water and mobile ice crystals - and that somewhere below 100km there is some kind of mineral core ... but information about the internal chemistry was sadly lacking when I last looked, so I think it's difficult to say if there is sufficient available energy to sustain any form of complex life (as we know it) ...
    Nature abhors perfection; cats abhor a vacuum.

    "I don't know; I'm making it up as I go ..." Dr H Jones (Jr).
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  12. #11  
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    Quote Originally Posted by Cran
    Not sure what you mean by "Earthlike environment"
    Thinking with my stomach. Earthlike as in, where the hypothetical feedback forms hexagonal ice, pressure and temperature are suitable for codfish. Or something much like codfish.

    I just learned Europa's surface is thought to break down into significant quantities of oxygen, which tectonics cycle back under the crust. So even aerobic organisms are sustainable.
    A pong by any other name is still a pong. -williampinn
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  13. #12  
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    Quote Originally Posted by Pong
    Quote Originally Posted by Cran
    Not sure what you mean by "Earthlike environment"
    Thinking with my stomach. Earthlike as in, where the hypothetical feedback forms hexagonal ice, pressure and temperature are suitable for codfish. Or something much like codfish.

    I just learned Europa's surface is thought to break down into significant quantities of oxygen, which tectonics cycle back under the crust. So even aerobic organisms are sustainable.
    if the speculation is proven, then it's very interesting ... if the dissociation occurs at the surface, though, I'd question whether Europa has sufficient mass (gravity) to retain the oxygen long enough for tectonic recycling ...

    as for organisms, it still depends a lot on the chemical soup beneath the ice ...
    Nature abhors perfection; cats abhor a vacuum.

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