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 What
if we are all space aliens ?
Panspermia, the most controversial hypothesis about the origins
of life on Earth is gaining support.
The theory that we are all descendents of an alien life form that
'seeded' our planet billions of years ago becomes stronger with
time, also because we realize that much of what we considered 'scientifically
impossible' can instead happen.
According to this theory, very resistent spores of very simple
and tenacious life forms can travel across space, and - although
very rarely - they can meet planets with life-supporting conditions.
When this happen, such organisms have their chance to start a new
evolution ... comets are the most likely vectors for entities like
those, and in this way life could be 'contaged' from planet to planet,
even from star to star.
This theory not only does not answer to the crucial question of
how life would have evolved in the first place, but also challanges
many beliefs about the feasibility of this space travel. The fact
that we have found recently mars rocks on earth, with possible fossils,
and that we now know that comet dust continuously hits our planet
and enters in our athmosphere makes things less easy. However it
was not widely believed that life forms could survive the rigours
of interplanetary space.
Two new studies (on major journals like Science and Nature) now
could change things:
* One study, reported in the October 27 issue of the journal Science,
shows that a space rock could successfully transport life between
planets.
* Another group of researchers, reporting in the October 19 issue
of Nature, claims to have found and revived bacteria on Earth that
were dormant, in the form of spores, hiding in New Mexican salt
crystals for 250 million years. Scientists called the implications
of this second discovery profound, suggesting that if further study
bears out the findings, it could mean bacterial spores are nearly
immortal.
Now it is a bit harder to criticize the Panspermic hypothesis ...
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