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Asteroid Belts May Determine Presence of Complex Life

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  • derhexer@aol.com
    Interesting speculation from The Daily Galaxy _http://tinyurl.com/b5325pq_ (http://tinyurl.com/b5325pq) Of course, they are building a model based on a single
    Message 1 of 1 , Nov 1, 2012
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      Interesting speculation from The Daily Galaxy
      _http://tinyurl.com/b5325pq_ (http://tinyurl.com/b5325pq)

      Of course, they are building a model based on a single instance.

      Two NASA astronomers suggest that the size and location of an asteroid
      belt, shaped by the evolution of the sun's planet-forming disk and by the
      gravitational influence of a nearby giant _Jupiter_
      (http://www.dailygalaxy.com/my_weblog/2012/10/jupiter-undergoing-cataclysmic-changes.html) -like planet,
      may determine whether complex life will evolve on an _Earth-like planet_
      (http://en.wikipedia.org/wiki/Terrestrial_planet) . _Rebecca Martin_
      (http://rebeccamartin.com/) , a NASA Sagan Fellow from the _University of Colorado
      in Boulder_
      (University%20of%20Colorado%20at%20Boulder)&t=h) , and astronomer _Mario Livio_
      (http://en.wikipedia.org/wiki/Mario_Livio) of the _Space Telescope Science Institute_
      (Space%20Telescope%20Science%20Institute)&t=h) have concluded that _Solar
      systems_ (http://en.wikipedia.org/wiki/Planetary_system) with life-bearing
      planets may be rare if they are dependent on the presence of asteroid belts of
      just the right mass.
      Asteroids may have delivered water and organic compounds to the early
      Earth. According to the theory of punctuated equilibrium, occasional asteroid
      impacts might accelerate the rate of biological evolution by disrupting a
      planet's environment to the point where species must try new adaptation
      strategies. The astronomers based their conclusion on an analysis of theoretical
      models and archival observations, including infrared data from NASA's
      _Spitzer Space Telescope_
      ntists.html) .
      "Our study shows that only a tiny fraction of planetary systems observed to
      date seem to have giant planets in the right location to produce an
      asteroid belt of the appropriate size, offering the potential for life on a
      nearby rocky planet," said Martin, the study's lead author. "Our study suggests
      that our solar system may be rather special."
      Martin and Livio suggest that the location of an asteroid belt relative to
      a Jupiter-like planet is not an accident. The asteroid belt in our solar
      system, located between Mars and Jupiter, is a region of millions of space
      rocks that sits near the "snow line," which marks the border of a cold region
      where volatile material such as water ice is far enough from the sun to
      remain intact. When Jupiter formed just beyond the snow line, its powerful
      gravity prevented nearby material inside its orbit from coalescing and
      building planets. Instead, Jupiter's influence caused the material to collide and
      break apart. These fragmented rocks settled into an asteroid belt around
      the sun.
      "To have such ideal conditions you need a giant planet like Jupiter that is
      just outside the asteroid belt [and] that migrated a little bit, but not
      through the belt," Livio explained. "If a large planet like Jupiter migrates
      through the belt, it would scatter the material. If, on the other hand, a
      large planet did not migrate at all, that, too, is not good because the
      asteroid belt would be too massive. There would be so much bombardment from
      asteroids that life may never evolve."


      The voices in my head may not be real, but they have some great ideas!

      [Non-text portions of this message have been removed]
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