how to create terrain on a sphere in script?

Hello everyone, i have been wanting to create a proceduraly generated solar system, but it doesn´t look very good if all planets look prety much the same. so i was wondering if there is a way to create landscape on a sphere. i dont want you guys to write the code for me, but if you could provide me with ideas or sources where i can learn about this i would very much apreciate it. thank you all for your time.