Earth Impact | Universe Today

Written by Jerry Coffey

It is a beautiful day, the sun is warm and relaxing on your skin. Everything is just right for a swim and relaxation. A family picnic later, sounds great. Suddenly you hear a deafening boom as a fiery object screams across the sky. It sounds like a bomb going off when it hits. A few seconds later a wall of flame, heat, and debris hits you, but you don't know. You are already dead. One of the first victims of an Earth impact by an asteroid more than 50 km in diameter. Soon after the blast wave passes you, your ashes will be swallowed by the impact crater that will be more that 500 km in diameter once all of the ejecta settles around the rim.

Humans are not the only immediate victims. Every plant, animal, down to the smallest single cell organism within thousands of km will die from the climate changes caused by the Earth impact. It was a smaller asteroid that hit the Earth 65 million years ago and killed all of the dinosaurs and up to 75% of all life on the planet. Why would things be any different this time.

Does this sound like a sci-fi paperback? The truth is that an Earth impacts happen on a yearly basis. Most of them are small enough that they burn up in the atmosphere. Occasionally one hits the Earth that is smaller than a baseball. The last one to cause significant damage was near the Tunguska River in Siberia in 1908.

An Earth impact is real enough that the Air Force and NASA have teamed up to observe and catalog every near Earth asteroid (NEA) that they can find. There are scenarios in place to prevent a major impact in the future, but will they be enough? There is so much that we may never know about Earth impacts that it is hard to prepare for the unknown.

Earth impact is a real threat. The countries of the world are as prepared as they can be, but no one can possibly know if it is enough. All that is known for certain is that an asteroid larger than 10 km can penetrate the atmosphere and cause devastating damage and climate changes that we may never recover from.

There is a great article on an Earth impact here on Universe Today and a good related episode on Astronomy Cast

Filed under: Astronomy

Tags: Asteroids, Earth impact, impact craters