Which worlds could humanity actually call home beyond Earth? From ancient Mars and a future Moon city to moving billions of people off our planet and reaching an Earth-like world, these scenarios explore the places humanity might one day be able to live. 00:00 What If You Lived on Mars 1 Billion Years Ago? 18:23 What If We Moved All 8 Billion People To Mars? 44:28 What If NASA Built a Moon City by 2032? 1:06:16 What If You Traveled to Earth 2.0? Enjoying this video? Dive even deeper into the world of science and discovery with Popular Science, the free streaming channel bringing you more of what you love from What If, plus epic explorations in engineering, rocket launches, movies, space, and Earth sciences underknown.com/popularscience Support us on Patreon: patreon.com/whatifshow/membership Check out our other channels: How to Survive: bit.ly/how-to-survive-show Animalogic: youtube.com/@UCwg6_F2hDHYrqbNSGjmar4w Aperture: bit.ly/ape...