Posts Tagged ‘panspermia’

Every now and then, a paper appears on astroph that has us thinking – is this serious? Or is this an imagination gone a tad wild? (Or is it April 1st?) For example, a friend at the IoA once wrote a proposal (for a graduate course) aiming to find extrasolar planets through bioluminescence. Rarely has an observing proposal been so entertaining.

So it was this week when this paper appeared on astroph. The proposal is as follows: “Genomic complexity” estimates that life on earth began 10 billion years ago (give or take three billion years). This is older than the solar system. A slight problem, perhaps. Suppose, perchance, that life didn’t develop on Earth. Suppose that, long before the solar system was formed, a planet was ejected from another planetary system. En route, this wandering planet (or rogue planet) forms life deep underground, shielded from cosmic rays, lethal radiation and freezing temperatures on the planet surface and warmed by radioactivity of the planet core.

Now suppose that the planet wanders into our solar system. The planet is most likely on an unbound orbit, and thus this will not be a long visit. (The paper estimates this number at around 43 years). But, bathed in the radiation of the sun and the solar wind, the surface of the planet may be stirred up enough to throw rocky shards off the guest planet. Should one of these shards reach a newly-formed Earth, and carry with it life-forms, then we would receive a population of organisms with a few billions of years of evolution behind them – they would be older than the Earth itself. (more…)

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