Re: what if Earth were tilted 90 degrees instead of 23 ?

James Goldman <[EMAIL PROTECTED]> wrote in message news:<[EMAIL PROTECTED]>...
> Interestingly, I just noticed that this month's Astronomy has a note at the
> top of page 31 on this very subject. 
> 
> I says that computer simulations suggest that Earth - with its current
> geography, but with a 85 degree tilt - would have fierce seasons but could
> sustain life. However, they don't provide anywhere more information can be
> found, though. I wonder why 85 degrees and not 90?

It's likely because the arctic circle would be much closer to the
equator than now, so flora and fauna that required tropical conditions
would be much more densely packed into the equatorial regions.
However, with such a small equatorial region, it's not at all likely
that the Earth would have any "tropical" plants and animals, they'd be
all extreme-weather specialists. Plus we'd have no polar icecaps
whatsoever, because there would be too much heat falling on the lit
poles, which would melt them for part of the year, and the unlit poles
would soon enough become lit poles too at the other end of the year.