Coral reefs are built by tiny animals called coral polyps.

The Amazon River discharges about 20% of all fresh water that flows into the world's oceans.

The Tardigrade can survive the vacuum of space.

Sharks have been on Earth longer than trees — sharks evolved around 450 million years ago, trees around 350 million.

Some plants grow toward light sources.

There is enough gold inside Earth to coat the entire planet’s surface.

Tornadoes form from powerful rotating thunderstorms.

Lightning can strike more than once in the same place.

Bananas are naturally radioactive due to potassium.