Re: Dirty Snowball Worlds

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.

http://en.wikipedia.org/wiki/Snowball_Earth

Take a look at that model temperature graph on the right: most of the
Earth has temperatures below freezing, though there's a band around
the equator that's warmer.

If you have half an hour, this site gives a good back-and-forth of
arguments for and against it:

http://www.snowballearth.org/

But whether or not the Earth was ever in such a state, it seems like a
plausible condition for an otherwise Earthlike planet.  (Albeit one
around a slightly cooler sun; back in the Proterozoic, the Sun was
5%-10% less luminous than it is today.)

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.


Doug M.