Think about this, earth is really big but then a lot of the planets in our solar system, some bigger and some are smaller, then of course there is outside of our solar system, the Orion arm of the Milky Way. Inside each system in this arm of the galaxy there are millions of stars each with their own planets in orbit around them.further out from our arm of the galaxy there are more arms each with millions of stars and billions of planets and moons. Further away from the Milky Way there are other galaxies full of planets and stars, moons and rocks, at the centre of each galaxy there is a massive black hole. Now all of these galaxies are only a spec of dust compared to the sheer size of the universe. We do not know if there are other universes but if they were they would be like ours, really really big. And the only thing that exists that is more larger than anything ever? [spoiler]your mum[/spoiler]