PLEASE NOTE:
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CCNet DEBATE, 20 November 1998
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ASTROBIOLOGY & PANSPERMIA
From Andrew Y. Glikson <andrew.glikson@anu.edu.au>
Dear Benny Peiser,
I have followed Chandra Wickramashinghe and Fred Hoyle's
Panspermia ideas for some time with fascination and, I must
admit,
a degree of incredulity, for the following reasons:
1. Given the presence of organic molecules in meteoritic
and
interstellar dust, it is well known that the distinction between
organic matter and bacterial life forms is not a quantitative one
but a qualitative quantum jump. As I am not aware of a
discovery
of bacteria in extraterrestrial particles to date, I fail to see
the evidence for the Panspermia assertion.
2. How is Panspermia reconciled with the physical limits on
the
survival of DNA, which I believe breaks down at temperatures
lower
than those to which interstellar particles are exposed during,
for
example, cometary sun-grazing or atmospheric entry?
3. In my readings of early terrestrial evolution and the
role of
meteoritic impacts I have not yet come across a rationale as to
why Earth, given the presence of water and favorable surface
temperatures, is any less suited as a cradle for bacterial life
than any other planet or interstellar space?
4. Finally, would proponents of Panspermia care to comment
on the
ideological parallels between Panspermia and UFO-type cults -
which seem to share peculiar philosophical tenets, namely (1)
importation of life/culture from outer space; (2) an
underestimation of the potential of Earth itself as a cradle of
life, evolution and culture, and (3) a lack of elementary
scientific evidence - ie. either for interstellar bacteria or for
UFOs?
Yours Sincerely
(Dr) Andrew Glikson
andrew.glikson@anu.edu.au
20 November, 1998