Who really knows one way or the other - when all's said and done, as an individual, this is really a question of faith.
Look at the question of water on Mars - up until last week, you could have asked anyone and they'd have said there's no water on Mars. That's because that's what "scientists" have been peddling for decades and we're talking here about the closest planet to us! They just don't really have a clue, all guesswork - like a dodgy mechanic examining your car. Not. A. Clue.
Beyond that the beliefs we have re the wider universe are, for the most part, the result of house of cards theoretical physics equations piled on top of each other and someone or other pulling real world interpretations out of the arses...