Re: Planets, materials, Oil reserves & permaculture

From: Technotranscendence (
Date: Fri Aug 11 2000 - 08:39:30 MDT

On Thursday, August 10, 2000 10:39 PM Robert J. Bradbury wrote:
> No the planets are not in our solar system. They are around
> other stars within a couple of hundred light years. I believe
> we are up to 50 planets and either 2 or 3 planetary systems.
> Lowest mass is slightly under Saturn (except maybe for those
> orbiting around the pulsar). Orbits are mostly fairly eliptical,
> which to some extent is a selection effect (because large
> Jupiters with orbits close to the star will be discovered
> first in these surveys). To get Jupiters close to stars,
> you are likely to have had planetary billiards occuring
> which is likely to create more elliptical orbits. I am
> *hoping* as time goes by, we will get more circular orbits.
> If that doesn't occur, then opportunities for life are
> going to take a significant hit.

The planets currently being found -- if that's what they indeed are -- and
their orbits appear to radically different from what scientists expected
other solar systems to be like. Though not doubt this is due to a sampling
error -- researchers are limited, for now, to finding planets in certain
ways which bias the research toward finding large planets in eccentric
orbits because these are the easiest to find -- I don't think anyone in the
1970s or 1980s would have predicted these particular types of orbits would
have been found at all.

What I'm leading up to here is the question of whether what has been found
is typical. Also, I'd like to know how these findings have affected
theories of planetary formation and of solar system formatiom. (My
knowledge of such is mostly limited to reading some of the popular
scientific publications (e.g., _American Scientist_) and some of the bigger
journals (e.g., _Nature_).) Have workers in these areas had to revise their
theories in light of the data?

Daniel Ust

This archive was generated by hypermail 2b29 : Mon Oct 02 2000 - 17:35:45 MDT