On Jan 3, 11:01 pm, Phil Hays <[email protected]> wrote:
> On Sun, 2010-01-03 at 09:27 -0800, Alastair wrote:
> > Hansen seems to believe that Venus had oceans, but that is now seeming
> > unlikely. It is now thought that Earth's oceans were formed from
> > impacts from Main Asteroid Belt Comets.
> >http://www.solstation.com/stars/asteroid.htm
> > These are icy outer asteroids which had there orbits distorted by
> > Jupiter. As their orbits became more elliptical, they collided with
> > Earth, which protected Venus and kept it dry. The runaway state of
> > Venus's atmosphere must be due to CO2, not H2O!
>
> A scale model might help to visualize.
>
> If the Earth is a peppercorn, then the Sun is a 20 cm ball about 26
> meters away. Get a peppercorn and a ball, and make a scale model of the
> Earth/Sun system. If you please, you could also add Venus another
> peppercorn 19 meters from the Sun, and the Earth's Moon, a bit of gravel
> 2 cm away from the Earth. Now imagine that there are comets coming from
> the outer solar system, in the neighborhood of Jupiter, another 110
> meters beyond the Earth.
>
> Just how many of these comets will the Earth prevent from hitting Venus?
>
> --
> Phil Hays <[email protected]>
What is described by Jewitt is main-belt comets, but these are not the
main comets, and Jewitt estimates there may be only 150. They are in
the main asteroid belt. What is being proposed is that the water on
the Earth came from icy asteroids which formed further than the main
asteroid belt from the Sun and closer to Jupiter. They arn't there now
because they have all crashed into Mars and Earth.
Cheers, Alastair.
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