# asteroid belt **URL:** \ **Category:** Factual Questions\ **Created:** [August 29, 2001, 2:16pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695 "2001-08-29T14:16:41Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![vanilla](https://avatars.discourse-cdn.com/v4/letter/v/f19dbf/32.png) [@vanilla](https://boards.straightdope.com/u/vanilla)\ **Post date:** [August 29, 2001, 2:16pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695/1 "2001-08-29T14:16:41Z")
Was it a planet, originally? One that broke up? ---
**Author:** ![DVous\_Means](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@DVous\_Means](https://boards.straightdope.com/u/DVous_Means)\ **Post date:** [August 29, 2001, 2:31pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695/2 "2001-08-29T14:31:21Z")
One of the stronger theories about the evolution of our solar system proposes there there may have been as many as 100 “proto-planetoidss” orbiting an evolving Sol (our Sun’s name). Over eons of time they progressively dwindled away due to collisions in a chaotic process of destruction and rebirth, as the fragments clumped together again and again in ever growing masses. The asteriod belt is thought to be a remnant of what was left over. But, as the Shoemaker-Levy comet impact Jupiter reminded us, the process isn’t finished yet… The BBC series “The Planets” has a really good discussion of this theory pitched perfectly at the layman level. I highly recommend it to get a better idea of the big picture. ---
**Author:** ![Fiver](https://avatars.discourse-cdn.com/v4/letter/f/e274bd/32.png) [@Fiver](https://boards.straightdope.com/u/Fiver)\ **Post date:** [August 29, 2001, 2:33pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695/3 "2001-08-29T14:33:36Z")
It’s either one that never formed, or one that broke up. No one knows for sure. But then again, what is a “planet” anyway? If you’re thinking of a Sun-orbiting body of a certain size, you should know that all the mass of all the asteroids in the Belt put together would be less than that of Earth’s Moon. So all that material never would have amounted to much even if it had coalesced (but don’t tell its mother!). ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [August 29, 2001, 2:42pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695/4 "2001-08-29T14:42:20Z")
[http://boards.straightdope.com/sdmb/showthread.php?threadid=67101](http://boards.straightdope.com/sdmb/showthread.php?threadid=67101) 😉 ---
**Author:** ![Cabbage](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@Cabbage](https://boards.straightdope.com/u/Cabbage)\ **Post date:** [August 29, 2001, 2:48pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695/5 "2001-08-29T14:48:15Z")
Well, there’s Bode’s law: > [@](#): > > A mathematical formula which generates, with a fair amount of accuracy, the semimajor axes of the planets in order out from the Sun. Write down the sequence > 0, 3, 6, 12, 24, … > and add 4 to each term: > 4, 7, 10, 16, 28, … > > Then divide each term by 10. This leaves you with the series > 0.4, 0.7, 1.0, 1.6, 2.8, … > > which is intended to give you the semimajor axes of the planets measured in astronomical units. > > Bode’s law had no theoretical justification when it was first introduced; it did, however, agree with the soon-to-be-discovered planet Uranus’ orbit (19.2 au actual; 19.7 au predicted). Similarly, it predicted a missing planet between Mars and Jupiter, and shortly thereafter the asteroids were found in very similar orbits (2.77 au actual for Ceres; 2.8 au predicted). The series, however, seems to skip over Neptune’s orbit. The form of Bode’s law (that is, a roughly geometric series) is not surprising, considering our theories on the formation of solar systems, but its particular formulation is thought of as coincidental. This, of course, doesn’t say anything about Jupiter, but I always thought it was interesting. I really don’t know much about this stuff, but as I understand, Bode’s law is generally thought of as somewhat interesting, but in large part just a coincidence. Anyway, my point is that the asteroid belt does fall into a nice pattern with the other planets. As far as I know, the common theory is that each of the planets begin as debris that clumped together over time, aided by larger and larger gravitational pulls of larger and larger clumps. Jupiter’s gravitational pull, because Jupiter is such a big planet, and because it’s so relatively close to the asteroid belt, provided enough “chaotic distortion”, I suppose, to disallow “big enough” clumps from ever forming in the asteroid belt, preventing a full blown planet from ever forming. I know there are some astronomers out there, so please correct any of this if necessary. ---
**Author:** ![Cabbage](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@Cabbage](https://boards.straightdope.com/u/Cabbage)\ **Post date:** [August 29, 2001, 2:51pm UTC](https://boards.straightdope.com/t/asteroid-belt/78695/6 "2001-08-29T14:51:45Z")
> [@](#): > > This, of course, doesn’t say anything about **Jupiter** I meant that to say _asteroid belt_ (and how it came to be there), not Jupiter.