How big is the universe?

Earth has a diameter of 12,742 kilometres. From end to end, it takes light 0.04 seconds to cross it. It is the largest rocky planet in the solar system, and the only one known to harbour life. The deepest point on its surface — the Mariana Trench — is 11 kilometres below sea level. The highest — Everest — rises 8.8 kilometres above it. That 20-kilometre range, the entire vertical extent of human experience, is less than 0.2% of Earth's diameter.