The K-T Extinction Event

The K-T Extinction Event happened 66 million years ago. A giant asteroid crashed into Earth and caused a disaster that killed the dinosaurs. About 75 percent of all species on Earth died. It is one of the most studied events in Earth's history.

The Asteroid Impact

The asteroid was about 6 miles wide, roughly the size of Mount Everest. It hit what is now the Yucatan Peninsula in Mexico. The impact created a crater over 110 miles wide called Chicxulub. The explosion was billions of times more powerful than a nuclear bomb. Fires broke out worldwide.

What Happened Next

The impact threw so much dust and ash into the sky that it blocked out the sun. Temperatures dropped and plants could not grow. Without plants, plant-eating dinosaurs starved. Then meat-eating dinosaurs starved too. Small animals that needed less food had a better chance of surviving.

Fun Facts

• The asteroid that killed the dinosaurs created a crater 110 miles wide in Mexico.
• The impact released energy equal to 10 billion nuclear bombs.
• Birds survived the extinction and are the living descendants of dinosaurs.

Did You Know?

Scientists did not discover the Chicxulub crater until 1978 because it is buried underground and partly under the ocean. A thin layer of the rare metal iridium found worldwide helped prove the asteroid theory!