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What happens to heavy atoms that come into the atmosphere as cosmic

  1. Jun 19, 2013 #1
    What happens to atoms such as gold, lead, and other heavy elements when they come into the Earth's atmosphere as cosmic rays traveling at close to the speed of light? I know that supernovas are generally the only natural place where atoms heavier than iron are formed, and they also shoot out nuclei at extremely high speeds.

    Do they have all of their electrons stripped, or just valence? Do the atoms deposit on Earth?
     
  2. jcsd
  3. Jun 19, 2013 #2

    davenn

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    I havent seen anything in writing to indicate that cosmic rays are made up of such heavy atomic nuclei such as gold, lead or anything heavier

    from wiki .....
    "Of primary cosmic rays, which originate outside of Earth's atmosphere, about 99% are the nuclei (stripped of their electron shells) of well-known atoms, and about 1% are solitary electrons (similar to beta particles). Of the nuclei, about 90% are simple protons, i. e. hydrogen nuclei; 9% are alpha particles, and 1% are the nuclei of heavier elements.[10] A very small fraction are stable particles of antimatter, such as positrons or antiprotons. The precise nature of this remaining fraction is an area of active research. "

    "Primary cosmic rays primarily originate from outside our Solar System and sometimes even the Milky Way. When they interact with Earth's atmosphere, they are converted to secondary particles. The mass ratio of helium to hydrogen nuclei, 28%, is similar to the primordial elemental abundance ratio of these elements, 24%.[39] The remaining fraction is made up of the other heavier nuclei that are nuclear synthesis end products, products of the Big Bang[citation needed], primarily lithium, beryllium, and boron. These light nuclei appear in cosmic rays in much greater abundance (~1%) than in the solar atmosphere, where they are only about 10−11 as abundant as helium"

    But from a NASA site

    it seems that heavier elements are sometimes recorded

    "About 90% of the cosmic ray nuclei are hydrogen (protons), about 9% are helium (alpha particles), and all of the rest of the elements make up only 1%. Even in this one percent there are very rare elements and isotopes. These require large detectors to collect enough particles to say something meaningful about the "fingerprint" of their source. The HEAO Heavy Nuclei Experiment, launched in 1979, collected only about 100 cosmic rays between element 75 and element 87 (the group of elements that includes platinum, mercury, and lead), in almost a year and a half of flight, and it was much bigger than most scientific instruments flown by NASA today. To make better measurements requires an even larger instrument, and the bigger the instrument, the greater the cost. "

    some food for thought :)

    yes, from the various articles I looked through, the majority of the cosmic rays (99%) are atomic nuclie ONLY.

    Dave
     
    Last edited: Jun 19, 2013
  4. Jun 19, 2013 #3

    jim mcnamara

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    I think what you want to research is the accretion rate to Earth's mass due to meteor bombardment.

    We are constantly being showered with meteors - from pinhead sized micrometeorites and larger. The chondtritic (rock like) meteors have trace amounts of heavy metals. These metals eventually become incorporated into soil and rock.

    As a result this adds "general rock" mass to the Earth. Plus really tiny amounts of heavy metals like iridium.

    Here is a discussion that attempts to quantify how often the earth is showered by incoming rock chunks:

    http://rsta.royalsocietypublishing.org/content/363/1837/2793.full

    The Earth both loses and gains mass from different sources every year.

    Example: loss due to atmospheric erosion from solar wind:

    http://scienceweek.com/st16.htm
     
  5. Jun 19, 2013 #4
    I read recently that heavy metals might have also been generated during neutron star collisions. as I recall the speculation was you needed a more neutron rich environment than the super nova might offer.
     
  6. Jun 19, 2013 #5

    jim mcnamara

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    What does that have to do with heavy metal content of:
    ios, molecules, dust particles, rocks
    falling to Earth or entering the atmosphere?

    We are talking about already existing atoms, probably old atoms. Circa the age of the Solar system. And. You are partially correct - heavy metal atoms are believed to be the result of stars' death throes. Please. You should cite your reference for the neutron star origin idea.
     
    Last edited: Jun 19, 2013
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