It looks like I was still using default - everything on, and Fantastic @ 1920*1080. (Later I turned off the false DOF for convenience.)So... what graphical settings were you using?
Ah, this might be more helpful, @Adriano - was just poking @The Ninjaneer's massive crafting base [in 0.7.6.4], and there happened to be a bugged looking planet rise in the background.
In the save, I've sent the base to inventory, so the game should now take less than 15 seconds to load. You don't have a whole lot of game time before it's above the horizon, but you can move that tech away and right, to use the hills, too.
The big circular shadow this one appears to make on the ground made me realise I've seen this glitch quite a lot, but not realised - when the planet is entirely invisible, during the day, even (I think).