The graphic that surrounds a planet when you click on it.... is not big enough for some planets. It's barely suitable for Jupiter sized planets, but anything bigger than that and you cant see it...
Also, when zoomed out into strategic mode, there needs to be an alternative method to showing which planets you have selected, you just cant see the current graphic well enough. And, in strategic mode, if you click a planet, then click somewhere else on the map (but not on another planet, ship, starbase, etc) the current graphic stays on the planet you last had selected...