Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Planetary Terrain Free.
Planetary Terrain
Planetary Terrain is a quadtree based procedural planetary terrain system for your space game! Smoothly travel from orbit to the ground.
Demos:
Earth-sized Planet
Small Planet
Features:
– Quadtree based dynamic, adjustable LOD
– Even earth-sized and bigger planets supported thanks to floating origin!
– Planets can rotate and have colliders
– Node Editor for noise to easily create good looking planets
– CPU or GPU based noise generation for top performance
– Foliage system to procedurally spawn grass and meshes on planet
– Scaled Space to easily add far away moons and other planets
– Different generation modes for planets including noise, heightmap and hybrid – Built in noise-based heightmap generator
– Heightmap Importer utility included
– Planet texturing based on elevation and slope or splatmaps
– Planet Shader with up to six textures and normal mapping
– 8-bit and 16-bit heightmaps supported
– Atmospheric scattering shader
– All source code included