" Like it said; shattered. That means most of it was destroyed and only fragments remained. Also, as I've said, Brolly performed this in a de-powered state. It was all under Paragus' command. He needed to lure Vegeta to New Vegeta, and of course he still needed it around so Brolly wouldn't destroy it. Brolly one-shotting it is the most plausible explanation available. The only others include him targeting nearly everyone of hundreds of millions of planets and trillions of stars within the galaxy and firing off that many blasts to destroy them all simultaneously, giving him targeting abilities and his attack speeds of such FTL levels as to be impossible for any other DBZ'er to measure. The other involves Brolly flying through the galaxy destroying each and every planet and star he comes across one at a time, but the rate of his speed would be billions, if not, trillions of times the speed of light for him to have accomplished this feat in a matter of seconds as indicated in the movie. Such a thing would place him a Pre-Crisis Superman levels of speed. And this is why we settle on the one-shotting move. It's more easily explainable and it's not like we haven't seen such things occur in fiction before either. "Then how would you know the DBU' s galaxy would have billions of stars? It takes place in completely fictional world (unlike in many other fictions in fact) , so that assumption is baseless. For all we know, the galaxy could only have a few thousand stars.