# Kuiper belt/Scattered disc

1. Oct 25, 2006

### FeynmanMH42

Why has this not coalesced yet to form a planet?

2. Oct 25, 2006

### tony873004

It never will. Eccentricities are too high, so any collisions would not be low-velocity. Collisions will grind things down instead of build them up. They also move very slowly, and the volume of space out there is huge, so collisions are not even that likely.