Re: Planets

Adrea Lommen from UC reported at the American Astronomical Society
meeting 
in Washington recently that she had detected a Mars sized planet by its 
interference with radio waves as it orbited a pulsar  - the first proof
I 
believe of any small rocky planet outside the solar system. The 74 or so

planets found so far outside the solar system are I think gas giants
(need 
to be big to be detected - the pulsar is a lucky break). Many have 
eccentric orbits that would prevent the formation of small rocky planets
in 
the biozone. 47 Ursea Majoris has two large gas giants in circular
orbits 
outside the biozone but Gregory Laughlin (UC same conference) has 
calculated that they are still too close in so the asteroid belt would
be 
in the biozone. Gas giants form the asteroid belt by preventing 
agglutination into a planet.

I suppose if a gas giant had a circular orbit in the biozone then a
large 
moon might be able to support life.

John

>John Lambshead wrote:
> >
> > Its beginning to look as if planetary systems are commonplace but
some are
> > very weird systems with gas giants in odd orbits. At least one
system with
> > gas giants in Sol-type orbits has been found and a Mars sized planet

> has been
> > discovered so small rocky planets so exist out there. Mostly the
technology
> > cannot detect anything much smaller than Saturn. Apparently, its
getting
> > better though.
>
>John,
>
>Can you cite your sources on these finding, esp the Mars-sized planet?
>And exactly what you mean by "Sol-type orbits"? Thanks.
>
>Mk

Dr PJD Lambshead
Head, Nematode Research Group
Department of Zoology
The Natural History Museum
London SW7 5BD, UK.
Tel +44 (0)20 7942 5032
Fax +44 (0)20 7942 5433
http://www.nhm.ac.uk/zoology/home/lambshead.htm
http://www.nhm.ac.uk/zoology/nematode/index.html

What a wonderful thing is the cat! on making it God said "That's that!
Supurrnatural selection has brought us purrfection -
which is a great relief to Me after My earlier mistake with the nematode
worm
(Rowena Sommerville)