err, I don't really like it so much. The skill is there, although hard to tell since blur destroys all detail. Your radial blur looks too filtered, because of the isolated top middleish asteroid and the bottom right one.
It's kind of grainy too. Collisions have been done before, but so has everything with Space. Your planets look like they could've been really nice, but again its really hard to see detail with the blurring. Colors are kind of on the ehh side.
The collision looks pretty legit, I like how you didn't over due it with explosions and blasts and particles. It came out pretty nice. If you were to eliminate the blur on the planet and object it would look much nicer I think
i do agree with some of the stuff here. the radial blur was to add a stronger focal point, as it didn't really look like it had any before. also, the asteroids were really slopppy made and therefor i had to blur em out its a bit of a speedpainting too, i think it was made in about 1 hr to 1 hr and 30 min.