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Earth's core (what if it burned out?)

  1. Dec 26, 2008 #1
    Hi, i have a question about earth's core. How does it keep on going (endless)? i mean will it last forever, and if it doesn't what will happen when it burns out? Do the other planets in the solar system have cores?

    Question 2: if we managed to get carbon dioxide to heat up mars, could it be a habitable place, like on earth?

  2. jcsd
  3. Dec 26, 2008 #2


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    Mars is a good example of a planet whose core has solidified. It is believed that this caused the loss of Mars' magnetic field which allowed the atmosphere to be blown away.

    So, I would say the answer to Question 2 is no.
  4. Dec 26, 2008 #3


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    Last edited by a moderator: May 3, 2017
  5. Dec 28, 2008 #4
    The questions, I believe, are, can the Earth core solidify completely and what would happen then?

    The answer can only be, we don't know. The scientific method is bound to fail here. We can measure things and interpret them some way or other and make (long term) predictions from that. But we can't test these predictions. For instance from http://science.nasa.gov/headlines/y2001/ast31jan_1.htm [Broken], if the solar wind pushed the atmosphere from Mars away due to the lacking magnetic field, why does Venus have such a dense atmosphere, also lacking a magnetic field?

    Some speculations:
    Last edited by a moderator: May 3, 2017
  6. Dec 28, 2008 #5

    Ivan Seeking

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    How long did it take?
  7. Dec 29, 2008 #6


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    Some facts.
    Last edited by a moderator: May 3, 2017
  8. Dec 29, 2008 #7
    The two questions aren't necessarily related are they? Well I don't know, but I will answer each one separately adding what little I think I know:

    1. First of all what do you mean by "going"? I will assume you mean the swirling around of molten iron in the outer core as this is the most kinetic aspect. The answer is convection, which can be broken up into two separate parts: (a) thermal convection due to the thermal boundaries at the interfaces between the core and the mantle and the outer core and the inner core, (b) compositional convection due to the crystallisation of molten iron into a mushy solid iron which is continually happening (note that this process releases the latent heat of crystallisation).

    No it will not last forever. But it won't "burn out" before the sun evolves into a red giant and kills us all anyway.

    Yes other planets have cores too.

    2. It would be habitable if it had the right gases in the atmosphere, oxygen being quite important for us humans, and more importantly liquid water. At the moment Mars is too cold to host liquid water, although there remains the possibility that it exists in very deep canyons or in underground aquifers. If you wanted to make Mars habitable on the surface you'd need to heat it up, greenhouse gases are probably the best way. Actually I don't know anything about how to make a planet habitable but I have friends who study this sort of thing and they assure me that it is theoretaically possible.
  9. Jan 9, 2009 #8
    Actually, 95% of the Martian atmosphere is already carbon dioxide and as is evident by temperature readings on Mars, it hasn’t managed to raise the temperature to cozy earth-like temperatures. The thin Martian atmosphere is slightly less than 1% as dense as the Earth’s, so it’s not likely to ever become life-sustaining for carbon-based life like those on Earth. Mars offers no serious promise for inhabitability by earthlings.

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