Subject: Re: How smart are SETI@homers?
From: Rich
Date: 19/05/2004, 17:10
Newsgroups: sci.astro.seti,alt.sci.seti,sci.space.policy



In infinite wisdom Sander Vesik answered:
In sci.space.policy Rich <someone@somewhere.com> wrote:

We can't detect Earth mass planets yet, but all indications from planets
we *can* detect indicate there are more low mass ones than high mass
ones.

By low mass, you mean source means near jupiter's mass rather
than 5 or 8 times jupiter mass. It most assuredly does not mean
terrestrial mass. Nor do we see planetary systems for many stars,
not yet anyway.

I think you are conflating 'near jupiter mass' (a lower bound near
jupiter mass) with 'terrestrial mass' and that is not supported by
the data we have at all. Further, many of the detected planets are
jupiter mass planets at or near 1 AU. That's around where we need a
terrestrial planet for ET to exist. Most of the observed stars with
planets could not harbor a terrestrial planet where it would need
to be.


This is wrong in several different ways:

    * the habitable zone is not centered around 1 AU for all
      stars

I think it's a reasonable starting place for SETI. For large stars,
the habitable zone may be out farther, but the star will burn out
long before intelligent life can form anyway.

    * large moons of super-jupiters residing in habitable zones
      are as likely to be hosts to life as terrestrial planets
      in such zones

Pure speculation.

    * a super-jupiter with a saturn-style ring in habitable zone
      would be *more* likely to host life than a terrestrial planet

More pure speculation.

    * most present considerations of habitable zone are overly       biased by teh relative sizes and atmospheric contents of       Venus and Mars

Say what?

    * almost no consideration has been given to planets with       Titan-style environments

Which planets are these?

This is not proof, but it's an extremely strong indication.

Not of the existence of terrestrial planets.

Interestingly, many of the things originally pegged as
planets have been found out to be brown dwarves, and are
now listed as 'not a planet'. And yet these occupy the
range from maybe 20 jupiter masses up. So in part we
have a label issue, we simply don't call em planets if
they are too massive, even if they are nowhere near being
stars.

Or maybe you are simply confused with the brown dwarf vs. planet thing?

No, I don't think so.

Rich