Will the asteroids eventually (re)form a 10th planet?

[Loren Booda]

Despite Jupiter's gravitational tides, is the asteroid belt gradually coalescing into a planet(esimal) to rival Mercury (and Pluto) in size?

[Phobos]

I suspect the answer is no. First, it seems that the asteroid belt is not a former planet that was ripped apart, but instead is the building blocks that failed to form a planet. As for forming a planet in the future, I doubt it because (1) Jupiter's gravity will remain an issue, (2) the asteroids are too far apart, and (3) asteroids are periodically ejected from the belt.

[tony873004]

Everything Phobos said, plus there's not enough mass in the asteroid belt. If all the mass came together into a single body, it would still be asteroid sized.

[Andre]

Clear

And would this also put question marks here (http://history.nasa.gov/SP-345/ch13.htm) about the accretion of planets from grain orbits?

It is derived that the accretion from circular grain orbits gives a slow retrograde rotation. Consequently, if there is "some reason to assume that Venus has accreted in this way, its retrograde rotation might be explained".

and "If we can show that the planetesimals from which Venus accreted moved in more circular orbits than the bodies from which the other planets accreted we may solve the problem of the anomalous rotation of Venus. A suggestion along these lines has recently been made by Ip (1974a)"

(Ip, W., and A. Mendis, 1974. On the effect of accretion and fragmentation in interplanetary matter streams, Astrophys. Space Sci. 30: 233)

Why would the accretion of Venus be so much different than the other planets?

[Frigga]

Please make sure that you include the suns 'warble' into your theory. It has a greater and more local effect on the inclusion and exclusion of material from the astroid belt.