From: Mike Lorrey (mlorrey@yahoo.com)
Date: Sun Jul 13 2003 - 20:39:25 MDT
--- Damien Broderick <damienb@unimelb.edu.au> wrote:
> At 07:55 AM 7/9/03 -0700, Robert wrote:
>
> >90 light years from Earth, the Sol-like star HD70642
> >has a 2x Jupiter mass planet orbiting in a roughly
> >circular orbit at 3.3 AU from the star with no large
> >planets detected in orbits closer to the sun.
>
> That's the one I mentioned the other day. Wouldn't this mung the Mars
> equivalent orbit into asteroids, and maybe bugger up the life zone if
> there's a potentially habitable planet at circa 1 AU? I can see two
> countervailing side effects: too much hard rain (that crud at 1.5
> AU), and not enough (if it's mopping the rocks up--but then Mars is
> plentifully cratered).
First off, we dont know how large and/or bright the star is. Saying a
star is 'sol like' is actually a rather broad brush to cover a rather
significant range of yellow dwarf sizes and brightnesses. How bright it
is tells us where exactly the life zone is, and therefore whether a
jovian at 3.3 AU is a good or bad thing.
Secondly, our moon is at least as important as Jupiter at saving our
asses from being nothing but a gravel pit. It is the significant
feature that no amount of astronomy can determine unless we actually GO
to one of these systems, or build one honking huge interferometer.
=====
Mike Lorrey
"Live Free or Die, Death is not the Worst of Evils."
- Gen. John Stark
Blog: Sado-Mikeyism: http://mikeysoft.zblogger.com
Flight sims: http://www.x-plane.org/users/greendragon/
Pro-tech freedom discussion:
http://groups.yahoo.com/group/exi-freedom
__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com
This archive was generated by hypermail 2.1.5 : Sun Jul 13 2003 - 20:48:47 MDT