Asteroids are a dime a dozen, astronomically speaking. These small rocky shards from the formation of our solar system whiz harmlessly past Earth several times a week. About once a year, a car-size asteroid hits the atmosphere and flames out.

The risk of a large asteroid hitting earth is exceedingly rare, scientists insist. Yet the idea of a catastrophic, life-threatening asteroid collision seizes human imagination.

If a hulking asteroid does in fact hit us, a new study has dutifully examined which of its effects would likely claim the most lives.

The researchers explored seven deadly outcomes associated with asteroid impacts: heat, shock waves, flying debris, tsunamis, wind blasts, seismic shaking and cratering. They estimated the lethality for impacts of different sizes. And they ranked the effects from most to least deadly – how many lives would be lost to each effect.

The deadly winner: wind blasts and shock waves. Combined, they’d claim more than 60 percent of life lost in an asteroid impact, according to the study. The atmospheric pressure generated in the hit would create shock waves that would rupture internal organs. Wind blasts would be powerful enough to flatten forests and hurl human bodies.

“The likelihood of an asteroid impact is really low. But the consequences can be unimaginable,” said Clemens Rumpf, a senior research assistant at the University of Southampton in the United Kingdom and lead author of the study. It was published in Geophysical Research Letters, a journal of the American Geophysical Union.

Runners-up in destruction of life, according to the study:

• Heat would account for nearly 30 percent of lives lost. Nearby populations could hide in basements or underground, Rumpf said.

• Tsunamis would account for 20 percent of lives lost, according to the study.

• Cratering and airborne degree would be responsible for fewer than 1 percent of deaths.

• Seismic shaking, accounting for just 0.17 percent of casualties, would be of least concern.

Rumpf and his team modeled 50,000 artificial asteroids ranging in size from 49 feet to 1,312 feet in diameter, the size that most frequently hits Earth.

They found that land-based asteroid impacts were an order of magnitude more dangerous, on average, than asteroids that landed in oceans. Only asteroids that spanned at least 60 feet in diameter were lethal.

Rumpf hopes the study will help mitigate loss of life in the event of an asteroid attack. Small towns may best protect themselves by evacuating should an asteroid 98 feet in diameter head their way. If an asteroid more than 650-feet in size threatens a big city of 1 million or more “It may be worthwhile to mount a deflection mission and push the asteroid out of the way,” Rumpf said.

He plans to present the study at the 2017 International Academy of Astronautics Planetary Defense Conference in Tokyo, Japan in May, where experts will discuss the threat of asteroids and comets and how to deflect them.

Until then, watch the latest not-so-bad actor, 2014 JO25, careen past Earth on April 18, 2007 in these radar images from NASA’s Jet Propulsion Laboratory in Pasadena, Calif.

The bright, spinning, peanut-shaped asteroid did not hit us. The ancient 2,000-foot object safely passed by at a distance of 1.1 million miles. And it won’t be back for about 500 years.

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