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

[Sterling K. Webb]

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