since you asked for a critique I will gladly talk a bit more about the picture.
the debries of the ring and the planet seem to move upwards also like the comets so I assume there is a heavy body out of picture that pulls them up, and maybe also be the reason of the planet tearing apart. Nothing much to say about the technique, wonderful, both lightning and composition, I also like the three brightests stars you put to draw a little bit of attention to the background and appreciate it better. By the way, another reason for removing the small moon is that there can't be "a moon of a moon" it would eventually form a normal moon of the big planet or tear apart or something, unless you already knew this and decided to put it anyway (I also do it sometines). There you have my last two cents.
the composition and grey tones are wonderful, the only thing I don't like is the: moon of the moon, I think it's not necessary, if you think removing that moon will leave that part of the picture empty, why don't you try doing something on the big moon instead? I think it would look better.
I have to say I really like the composition mate, the stars the comets... without words.
That's awesome. I like the feel of it. The way the planet is (basically) the only object in the picture. Makes me feel like it's breaking down, all alone. But the ring around it says to me that it's been around for a while. Like "I've had a good life, now it's my time to go" Overall very very nice