Death By Killer Asteroid: If The Impact Itself Doesn’t Get You, These Effects Just Might

We are constantly hearing various doomsday scenarios regarding the possible impact of a killer asteroid (or two), news generated to get attention simply by appealing to the common knowledge that the actual possibility exists that the Earth could at any moment be struck by an asteroid that could do catastrophic damage to the planet and the living organisms thereon. And if you are the type of individual who worries about such happenings, a new study has detailed the various ways in which you are most likely to be killed by an asteroid should one make planetfall in your relative vicinity.

As reported this week, researchers at the University of Southampton in the United Kingdom conducted a study where they used computer models to simulate 50,000 asteroid impacts all across the globe. The impactors ranged in size from 50 feet to 1,300 feet (15 to 400 meters) wide, this being the size range of the most common space rocks hitting the Earth. The simulations were used to calculate the number of deaths due to seven effects created by the asteroids’ impacts: shock waves, wind blasts, heat, flying debris, cratering, seismic shaking, and tsunamis.

Since shock waves and wind blasts occur in tandem, they accounted for 60 percent of deaths during an asteroid impact event, the study found. However, when broken down, the shock waves were the most lethal of the pair. Another nearly 30 percent of deaths were caused by the intense heat generated upon impact. Tsunamis produced by impacts accounted for most of the remaining deaths.

The impact effects least likely to kill you — but still deadly — were flying debris, cratering, and seismic shaking, all of which registered less than 1 percent of the deaths. Altogether the three only accounted for 1.28 percent of those killed, with 0.91 percent of that number dying by flying debris.

“This is the first study that looks at all seven impact effects generated by hazardous asteroids and estimates which are, in terms of human loss, most severe,” lead author Clemens Rumpf, a senior research assistant at the University of Southampton, said in a statement.

Rumpf and his fellow researchers also determined that asteroid impactors that slammed into the ground are about 10 times deadlier than those that struck in the ocean.

This, of course, would be the source of tsunamis, the third deadliest effect. However, a December 2016 study conducted by scientists at the Los Alamos National Laboratory in New Mexico found that as the impact’s distance from shore — and the depth of the water at the point of impact — grew, the less likely that gigantic waves created by the impact would ever reach the shore to pose as any kind of danger. In short, for the tsunamis to be deadly, an asteroid’s impact would have to be relatively near the shore, which makes the odds of just such an occurrence extremely small.

Asteroid prior to impact
Asteroids that impact far out to sea are unlikely to cause deadly tsunami waves that reach the shore. [Image by Igor Zh./Shutterstock]

The University of Southampton researchers also found that space rocks have to be at least 59 feet (18 meters) wide to be lethal. The Chelyabinsk meteor that detonated over Russia in February of 2013 was estimated to be at least 65 feet (20 meters) wide. The explosion’s shock waves shattered windows and damaged buildings in at least 10 cities and sent more than a thousand people to the hospital (although not one individual was killed).

But deadly asteroids exist. NASA and other space agencies spot and track the space rocks and have thus far identified over 16,000 near-Earth objects. About 95 percent of asteroids capable of threatening human civilization, those that measure at least 0.6 miles (one kilometer) wide, have been detected, astronomers believe.

Still, there are plenty of dangerous asteroids yet undiscovered. Rumpf said that the Earth is hit by an asteroid measuring at least 190 feet (60 meters) wide every 1,500 years. An asteroid measuring 1,300 feet (400 meters) wide makes an impact every 100,000 years.

An asteroid prior to impacting a city
Large asteroid impacts on land are rare, given that Earth is 70 percent covered with water. [Image by Johan Swanepoel/Shutterstock]

To get an idea of how devastating a killer asteroid impact might be, a March study concerning impact effects revealed that an asteroid measuring 1,800 feet (550 meters) in diameter crashing to Earth in Chicago would kill 9.5 million people. Such an asteroid would, the study found, unleash a fireball outward from the epicenter for over 10 miles and collapse buildings within an 82-mile radius.

“The likelihood of [a serious] asteroid impact is really low,” said Rumpf, “but the consequences can be unimaginable.”

[Featured Image by Vadim Sadovsky/Shutterstock]