SETI Researchers Affirm Planetary Privilege Criteria 06/24/2005 In the weekly SETI
Thursday column on Space.com,
Douglas Vakoch corroborated two claims made about the habitability of
planets in the film The Privileged Planet : namely, (1) smaller stars have smaller habitable zones or
“Goldilocks” zones where life can exist, and (2) planets within the
habitable zone of a small star are closer in, tending to tidally lock one
face toward the star – reducing the chance for habitability. They
admitted even more, that such conditions (if an atmosphere existed) would
“whip up enormous wind velocities.” They balanced that bad news with
hopes that such worlds might have enough greenhouse effect to moderate the
winds. Since the discovery of Gliese 876, the smallest extrasolar
planet so far, astrobiologists and SETI researchers are taking a second
look at smaller M-class stars as homes for habitable planets. None
of the ones surveyed so far has a Jupiter-class planet, so the thinking is
that most planets might be small rocky worlds around small, warm stars.
How much hoc can an ad hoc hawk for an
ad hoc post
hoc post? An M-class star needs a Jupiter for its comet
shield, remember? And is intelligent life going to thrive on the
dark side of a tidally locked world in time to build a flashlight, let
alone a radio telescope? Or is it going to bake in its sun forever
on the lit side and never see the stars, dreaming of who else is out
there? Maybe there is a thin great circle on its twilight zone
suitable for life. Don’t count on a booming economy,
though. Don’t expect sitcoms or even kid fare on the M
channel. If Goldilocks had to broadcast from such a world she
would move to a nicer zone. Like the film suggests, that leaves
out 90% of the market.
[2005/06/24] SETI Researchers Affirm Planetary Privilege Criteria
