Re: Dirty Snowball Worlds

sigidu...@[EMAIL PROTECTED]
 wrote:
> On Feb 17, 11:03 am, Logan Kearsley <chronosur...@[EMAIL PROTECTED]
> wrote:
>
>
> > Thoughts?
>
> This sounds very similar to "Snowball Earth", a theory that involves
> super-ice-age conditions in the late Precambrian period.
[...]
> One other problem is that Snowball Earth would have been a temporary
> state, lasting only some tens of millions of years.  But that could
> probably be handwaved too.

Similar, but not identical. It needs to be a permanent condition, so
there's at least a good billion years with large areas illuminated but
in deep freeze. If the planet is geologically active, carbon dioxide
will build up until it causes the Snowball Earth to melt. As I said
for idea #2, there needs to be some reason why that sort of thing
can't happen. I think it can be handwaved for idea #1 by saying that
higher CO2 pressure just causes more CO2 to precipitate out on the
antistellar cap, but that's not an option for #2.

-l.