Holy crap that is an amazing picture. Though I don't think an asteroid would have that sort of effect. I doubt it would go in one side and out the other like a bullet, it would just smash into the side and blow that whole side off, leaving the rest a destroyed fractured mess.
Anyway, if I was him I would sit down and watch the fragments of Earth drift off into space. I mean, what are the chances of that happening? It's a once in a lifetime occurence, and it's beautiful, so I would watch. Obviously I would be in shock and my mind would be numbed to the fact that everything I've ever known is destroyed. So I would sit until my air ran out or aliens would come pick me up.