Now this is remarkably easy to do. Well I think so... But I invented the technique (well I didn't follow a tutorial anyway).
Now to acheive a planet like this... V V (Yes there is no atmosphere...)
Now to make a planet like that is surprisingly easy.
Step one.
Make a geosphere, radius 160, segments 20, type icosa.
Step two.
Copy them twice. Like so.
Step three.
Hide one sphere for now, select a second sphere and apply a noise modifier to it. Play with the settings until you have something you like.
Step four.
Unhide that hidden sphere. Increase it's size by .1
Step 5.
Shell the sphere using these settings. (Roughly)
Step 6.
Now select our noise-mapped sphere and select boolean, like so.
Step 7.
Select our shelled sphere as operand B. (Colour changed for viewing purposes.) It should end up looking like this.
And whoila, it's done! Basically anyway. You can further apply noise modifiers to "rough up" the terrain, but make the strengths very small. Say between 1.5 and 0.1 with fractal and roughness set.
you can also use extruding, bevelling, etc to make mountains, massive canyons or valleys etc. But make the changes very small, this is a planet after all and not much detail should actually be modelled.
As for the texturing you are on you own, i'm still trying to figure that out.