>Howdy, Hilmar.
>
>>Too little is known about this far-off asteroids - err, "dwarf planets". But
>>the answer is probably "no", there is probably no ring around Pluto,
>>Sedna, or Xena.
>
>Personally, I don't think Pluto should be a planet. IMHO, I believe
>that Pluto was probably created when "the planet that was the asteroid belt"
>was destroyed. This "planet" more than likely was loaded
>with water, and when some celestial object nuked it, all that water was
>thrown out and about, creating Pluto and Sedna. Either that, or when Mars
>got hit by asteroids (created from the destruction of the "planet/asteroid belt"),
>its water was ripped away and thrown all over the solar system.
>
>
>Admittedly, a lot of the water that was in the solar system has been
>consumed by Jupiter and the Sun, but I'd be willing to bet that
>some bright astrophysicist can calculate most of this out and
>at least prove that Mars' water didn't "just vanish" but is still
>with us today, only it's in the form of comets and so-called planets,
>such as Sedna and Pluto.
>
>Hmmm. I'm wondering if some physicist has tried to calculate the relative
>mass of the asteroid belt and calculate the size of the planet that was
>probably once there. Also, I wonder if someone has also calculated planetary
>orbits based on this therohtical planet. Something tells me -- no way!
>
>I'd also be willing to bet that when the "planet that was the asteroid belt"
>got nuked, asteroids bombarded the Earth, and that's the pounding that
>created the moon and the Earth's tilt on it's axis.
>
>Anyone care to wager that I'll be proven correct? I bet a free upgrade
>to VFP 10, 11, 12... :^)
>
>
>Randall

I read in some older book about the asteroid belt between Mars and Jupiter. While there were some theories about a destroyed planet, it seems that most astronomers (at that time) thought it likely that a planet didn't form in the first place, because gravitational interference of massive Jupiter.

Judging by some articles I am just reading on the Wikipedia, it seems the "Phaeton (or Phaethon) hypothesis" (the hypothesis of a destroyed planet) is not generally accepted nowadays. From "Asteroid belt": "...A key problem with such an hypothesis is the staggering amount of energy required to achieve this kind of effect." Pressumably, such a planet destruction could be explained by a civilization with technology much more advanced than ours, but not by usual astronomical events.

Articles consulted:
http://en.wikipedia.org/wiki/Asteroid_belt
http://en.wikipedia.org/wiki/Phaeton_(planet)