About 4.5 billion years ago, the solar system was just a giant, spinning cloud of gas and dust. Today, it's flat. Here's how that happened.
Some animals, such as poison dart frogs, carry enough toxic chemicals to kill multiple adult humans, but they've evolved tricks to avoid poisoning themselves.
These planets are mostly made of gas, but a spaceship would have a rough time trying to get through a giant planet like Jupiter or Saturn.
Particle accelerators can help scientists measure the smallest and largest particles in the universe.
Our planet is constantly moving, racing around the sun and spinning on its axis. But how fast does it move?