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Possible for giant iron planet?

  1. Feb 21, 2007 #1
    While I know iron isn't the most common element in the universe, is it possible that there is a jupiter + size planet made primarly of iron? Also, when it comes to blackholes - would a massive iron planet form a black hole due to it's immense mass? What would be the minimum mass to form a blackhole, or is blackholes reserved strictly for dying stars and centers of galaxies?
    Last edited: Feb 21, 2007
  2. jcsd
  3. Feb 23, 2007 #2
    A planet of that size would likely attract lots of gas and dust coming its way, so that it would end up no longer being naked. Perhaps it is possible.

    The earth is mostly of iron, so we can consider a black hole of the same density (5515 kg/m^3).

    Since a black hole must have 6.73426629 * 10^26 kilograms for every meter of radius, the iron sphere (incapable of fusion) would have to be 1.14978957 * 10^38 kilograms (i.e. 58 million solar masses) with a radius of 170,737,170 kilometers, much more hefty than the sun is. I really doubt a black hole could be formed this way, or the existence of such an object. I really really doubt that my understanding of this is complete, so let's someone else pitch in....

    Last edited: Feb 23, 2007
  4. Mar 2, 2007 #3
    Why would the iron sphere need to be that massive? All it needs to be is dense enough to form a blackhole.
  5. Mar 3, 2007 #4
    It takes a massive amount of force to generate the density necessary for the creation of a black hole.
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