posted on Apr, 28 2012 @ 09:38 AM
reply to post by Scripter
I don't think discovering ET life in our solar system would settle the question of Extra-Solar life at all. There would still be plenty of room, as
there is now, for supposing that life was spread within our solar system by impacts, meteors, comets. We could still easily suppose that it
originated in one place and spread.
Finding life at great distances from us would be another matter. Distant systems are too far to have interacted with us. We could then say that
their life wasn't simply part of Earth's diaspora (or Mars'!).
Personally I favour panspermia. The spectral signatures of various biological precursors (amino acids etc) are pretty much everywhere we look in
interstellar dust. I think mixing and incident radiation, over long time scales, produces more complex molecules from the relatively simple space
dust. Then, like barnacles collecting on a whale's body, planets hoover up this dust. Once on planet, the dust is in a much denser environment and
can interact with its surroundings more frequently and in more complex ways.
This would be a much more efficient way of spreading life than having it appear independently, each and every time it occurs. In panspermia, the
entire universe is a simmering pot of ingredients, which are brought to the boil on dense objects, like planets.