More than 65 million years ago, Earth was struck by a giant asteroid (a space rock that moves around the sun and is smaller than a planet). Most scientists believe that this crash wiped out many animals, including the dinosaurs. How could an asteroid cause so much damage worldwide? Scientists recently found out.
According to the scientists, as the asteroid smashed into Earth it turned into a fireball. The burning rock melted and then vaporized (turned into a vapor, or gas). This hot vapor drifted high up into the air and spread quickly around Earth. It soon blocked out the sun. With no sunlight to provide heat, temperatures dropped drastically.
After a long period of time, the vapor cooled and turned into liquid particles that rained down on Earth. But by that time the cold temperatures had already killed off the dinosaurs.
Did You Know?
When this deadly asteroid struck Earth, it formed a crater that measured 180 kilometers (112 miles) wide. That's greater than the width of Maryland!