You nailed it! That certainly get's the point across that the moons of mars really are not moons as we think of moons. More like captured asteroids as you say.
So the bluish gradient captures our night sky as seen through our atmosphere, but how do you eliminate the flickering without having ridiculously high anti-aliasing values during rendering! Some stars just do not consistently render from frame to frame....even when the camera is not moving. I've tried everything (high AA settings, rendering out to twice the finished image size and then reducing in post) with only somewhat passable results (still not happy) --- even with static backgrounds. Admittedly, I have not done a space animation in quite some time (3 to 4 years), so maybe the denoising algorithms have improved significantly since then - but I would still like to hear how you did it.
Dave