TheHelmetDork said:
Right before Vader's conversation with the Emperor's hologramme/before Vader's flagship went out of the asteroid field for better transmission, there was a Star Destroyer that had one of those big balls destroyed by an asteroid. However the explosion caused looked like a dust explosion or something. What about this?

Don't worry about it my friend, its on the list here:

0:52:16 - When an asteroid hits the command tower on a Star Destroyer, the tower just magically dissolves belong the explosion element

And Adywan has expressed his displeasure with the shot. By the way, the whole top of the Star Destroyer is blown off, which is why in the next shot there's an officer covering his face as his communication (and his life) ends.