[meteorite-list] Another Study: Earth-like Planets May NOT Be Common...

From: Sterling K. Webb <sterling_k_webb_at_meteoritecentral.com>
Date: Sun Sep 10 18:44:19 2006
Message-ID: <000e01c6d52a$a246ced0$5f5ae146_at_ATARIENGINE>

Hi,

    One study says Earth-like planets may be common.
This study says exactly the opposite.
    If those hot gas giant orbits well inside the habitable
zone around a given star, and if that planet has reached its
position by migration through the habitable zone, then
Earth-like worlds may be far less common than would
otherwise be the case. Here's a good precis of research
on the migration question, as presented by a UK team.
    There's a discussion of why habitable planets,
depending upon the effects of migration, might be
found in a mere 7 percent of the systems surveyed.
Of course, 7% of a lot of stars is a lot of planets.
    The paper hasn't been published yet, but here's the
preprint:
http://arxiv.org/ftp/astro-ph/papers/0603/0603200.pdf


Sterling K. Webb
Received on Sun 10 Sep 2006 06:44:11 PM PDT