What to Expect When You’re Expecting Asteroids

By Christina Phillis

You have a greater chance of winning the Powerball lottery than you have of being killed by an asteroid, according to Tulane University researchers. Nevertheless, scientists at the University of Southampton wanted to find out what would happen if a giant asteroid did hit Earth. Using a computer model to simulate 1.2 million asteroid impacts, they found that, regardless of asteroid size, wind and shock waves would be the most common cause of death, accounting for six out of every 10 fatalities.

A Recipe for Disaster

To create a computer model that could predict mortality rates for asteroid strikes, researchers started with maps of human populations. They then added data on the probable amount of energy a falling asteroid would release at a given location. Using existing casualty data from studies of extreme weather and nuclear blasts, they estimated death rates at varying distances from the point of impact for asteroids between 50 and 1,300 feet in diameter. When they combined all of this data and added it to their computer model, the 1.2 million simulations fit into approximately 50,000 different scenarios for location, speed and strike angle.

Death á la Asteroid

Although the deadliest scenario would cause 117 million deaths, there is a silver lining to the findings — the majority of asteroid strikes would not cause any fatalities. No deaths were caused by sixty percent of asteroids smaller than 200 feet across. Asteroids smaller than 180 feet across would explode in Earth’s atmosphere before making it to the surface, generating intense heat and creating high-speed winds in their wake.

Before this study was conducted, scientists were already evaluating different solutions for dealing with a potential asteroid strike, like hitting the asteroid with a high-speed spacecraft or destroying part of its surface with a nearby nuclear blast. Researchers hope that knowing what to expect when an asteroid strikes may one day help world leaders to decide how to react to such an unpredictable event.