Did you know that every hundred million years or so, a violent collision of a sizable comet or asteroid with the Earth is likely to occur?
Meteor Crater in Arizona is about three quarters of a mile across and about 570 feet deep.
The impacting meteor was believed to have been roughly 150 feet in diameter. (click to enlarge)

The Solar System is teeming with billions of asteroids and comets, some of them with orbits that cross Earth's. Most of these objects are tiny and pose no threat to us. In fact, every year the Earth plows through clouds of particles that give us brilliant light shows called meteor showers. But amongst all of these billions of objects there are a few that are dangerous. Comets and asteroids large enough to create Meteor Crater hit Earth every thousand years or so. In 1908, a small asteroid exploded in the atmosphere over Siberia, laying waste to roughly 830 square miles of uninhabited forest. Truly massive objects, like the one that killed the dinosaurs 65 million years ago, leave craters roughly 100km in diameter and occur roughly every hundred million years. You can send your own deadly objects hurtling toward the planets at the Solar System Collisions page.

Return to the Astronomy Workshop