This just happened to me in a match I targeted enemy planet with a moon and it hit my planet. U can see the moons planned orbit going past my planet. Was kind of funny but is this an intended feature ?
Actually the moon escaped the planets orbit which it collided with and stayed in orbit of the star. Some of ejected mass might stay in the orbit and create moon over billions of years. What would been cool tough if the collision wouldn't have destroyed the halley engines and moon would have continued to it's intended target, causing two planets to be annihilated .