[In all his time here, everyone's universes have seemed so very different, and Earth is an outlier planet anyway. As far as Rocket is concerned, everyone is from the same Earth until proven otherwise, because that's how much Earth matters to him.

But an Earth that is actively being attacked by a species he knows about. That means something entirely different.]

First of all? 'Cause Chitauri don't up and decide to invade planets on their own terms. And second of all, 'cause I know what those are. D'you know how many frickin' times I've had to tell people "I don't know what that is" whenever they tried to explain their races or planets to me. Me! The guy who's been around the galaxy a few times.