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We humans like to think we're special, but astronomically speaking we've been shot down quite severely and humbly put in our place. We're not at the center of our solar system, nowhere near the center of our galaxy and certainly not at the center of the universe. But now comes great news for [...]
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Like human fingerprints, each planetary system is endowed with a level of uniqueness, but from perspetives that genericly address the basics they all have similarities. Considering the plethora of conditions from which protostellar clouds emerge and the vagaries of the angular momenta and heat capacity (opportunities for exchanging energy between the potential energy of molecular construction and the ensuing state changes and the garden variety kinetic energy arising from the gravitational compression of the cloud) of the various clouds, it seems reasonable to expect all sorts of configurations of planetary systems and for them to be more likely present than not. It is difficult to prescribe tolerance cones about each characteristic of the solar system from which to judge its similarity to others with the same relative number and size of planets. An outstanding element of uniqueness for the Earth is its Carboniferous Epoch (assuming it generated most of the fossil fuels) and the effect of exploiting carbon based fuels on our technological development.
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If I am correctly understanding the article published in Science, the simulations primarily varied only the mass of the protoplanetary nebula and its viscosity. Out of 100 simulations, only 6 produced planetary systems somewhat similar to ours. Unfortunately, they were unable to run enough simulations to be able to try to generate a distribution of planetary system types similar to what has been observed, so one has to be careful not to read too much into it.
The article is available to subscribers at
http://www.sciencemag.org/cgi/reprint/321/5890/814.pdf
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