What ever happened to the conjecture that the asteroid belt was caused from the disintegration of a planet between Mars and Jupiter? Also, how big would such a planet have been? Might it have been damaged when the 5th giant planet was ejected, or could it have been that 5th planet?
Pardon if this is a duplicative answer, I opened this in a tab some hours ago, and am now back home. :’)
The amount of mass *currently* in the main asteroid belt is insufficient to produce a planet if it were piled up in one pile. Without checking, I think Ceres (the largest of the main belt asteroids, and first one discovered) has more than half the entire mass, analogous to the way Jupiter has more mass than all the rest of the (known) planets combined.
The rubble of a planet that went kablooey could be expected to head off in eccentric paths, and to be gradually absorbed by other surviving bodies, such as Jupiter. The main issue for the late Thomas Van Flandern was, what mechanism caused his hypothetical planet (and eventually, planets) to explode?
Anyway, here’s an overview from TVF’s website, mentions Olbers who, in 1802, suggested that very origin for the main asteroid belt:
http://www.metaresearch.org/solar%20system/eph/eph2000.asp
The Nine Planets — Asteroid facts, pictures and information
http://nineplanets.org/asteroids.html
“The total mass of all the asteroids is less than that of the Moon.”