Let’s talk about the three main structures of the known universe. The solar system, the galaxy. and the universe. So, what’s the solar system? Yeah? Visitor: Like, the Earth, Mercury, Venus, our Sun? Presenter: There you go! Yeah, the Sun and all the planets, absolutely. Are we one of those planets? Is our Earth one of those planets? (Sure) of course! So what’s the galaxy? Visitor: A lot of solar systems. Presenter: A lot of solar systems, sure. It’s an island of stars that we live in. And, so, what is the universe? Visitor: Many, many galaxies. Presenter: There you go! Many galaxies, excellent. All right. Our Milky Way galaxy is just one of billions of galaxies in the universe.