Although quantitative estimates vary widely, the consensus is that
the history of the Earth is probably not unique. The figure of
about one million "habitable" planets per galaxy is considered not
unreasonable. Even if this value were overestimated by several
orders of magnitude, it would still add up to
trillions of potential cradles for life.
If my reading of the evidence is
correct, this means that trillions of planets exist that have
borne, bear, or will bear life. The universe is
awash with life.
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