I'm not sure if I just deactivated this by accident or what, but after fiddling with the graphics and interface settings within the game menus, I now seem to have the game stuck in a state where all planets and ships are permanently displayed with only simple 2d icons, rather than their 3d models, while looking at the galaxy map.
It doesn't matter what zoom level I'm at, and not even restarting the game helps. Strangely enough, all the stars are still shown in 3d. But the planets are just shown as simple white circles. I've tried reloading my previous savegame, and also starting a new game from scratch.
Anyone have any suggestions? I'm guessing I need to just reinstall from scratch, but I'm afraid this may happen again later even if I do.