What if the Moon was replaced by Jupiter? What if you saw the asteroid that killed the dinosaurs? What if gravity kept getting stronger?

What If Sim puts you inside the biggest "what if" questions in science and history. First-person 3D simulations of asteroids, supervolcanoes, black holes, giant waves, rogue planets, and the real disasters that changed the world.

Every number on screen is real science, from NASA, USGS and peer-reviewed research. Some of these scenarios are impossible. Some of them already happened.

You ask what if. We show you what happens next.
Comment your own what-if. It could be the next simulation.

New simulations every week. Subscribe so you don't miss the next one.