That asteroid that has that brief flash in it at the start of the chase is from a tiny asteroid colliding with it. While there are other shots where asteroids collide and cause explosions, this tiny one just drifts into the big one and makes a big flash. It seems a bit like overkill, but it does establish quickly just how treacherous the asteroid field is -- it's not even safe for other asteroids!

While we're on the topic of asteroids, I'm wondering: what of the asteroid that's actually a sneaker that flies by? Keep it, or composite another asteroid on top of it?