There will be an object detail layer on top of it filled with rocks and trees and stuff. I was trying to figure out a way to do that layer without resorting to a tilemap, array, or perlin noise
have a grid, with 3 perlin noise layers in it. Say they're 0-100. You'll have a grid size in x,y and a density threshold for the planet.
For each point in the grid:
if the value in the density noise layer is bigger than the planet threshold, the object stays.
the object then gets displaced by the percentage of the grid size indicated by the other two noise layers.
tada! since this also relies on perlin, you may do perlin tricks with it (it's repeatable)