Asteroid Strikes Could Be More Common Than Originally Thought

Asteroids like the one that exploded over Chelyabinsk, Russia in February could become more common, according to a recent study. The Russian meteorite shattered windows for miles and injured more than 1,000 people.

Experts at first labeled the Chelyabinsk asteroid a rare event, explaining that the event could happen once every 100 to 200 years on average. However, a team of scientists suggests now that the Earth is vulnerable to many similar space rocks.

The research was published in the journal Nature on Wednesday and estimates that strikes like the one in Russia could happen as often as every decade or two, reports The New York Times.

Peter G. Brown, a professor of physics and astronomy at the University of Western Ontario and an author of the two studies, explained that the prospect of more Chelyabinsk-sized asteroids “really makes a lot of people uncomfortable.”

The findings could result in more talk about planetary defense, including identifying and deflecting dangerous asteroids. Yahoo! News notes that meteors about the size of the one in Chelyabinsk are about four, five, or even seven times more likely to hit the Earth than scientists believed before.

NASA scientist Paul Chodas explained at a news conference that that means about 20 million space rocks the size of the one in Russia could be traveling through the solar system. Until February’s scary incident, NASA only searched for space rocks 100 feet wide and larger, believing there was little danger with smaller asteroids.

However, the Chelyabinsk meteor was only 60 feet across, yet managed to explode with the force of 40 Hiroshima-type atom bombs. The flash temporarily blinded 70 people and caused dozens of skin-peeling sunburns when it struck shortly after dawn. In the recently released studies, Dr. Brown and his colleagues discovered that about 60 asteroid explosions happened in the past 50 years.

While most of the explosions came from smaller asteroids, the data suggested the somewhat larger ones impacted more frequently than expected based on sky survey estimates. That could mean two things, either the Earth has been rather unlucky recently, or the estimates on Chelyabinsk-sized asteroids are too low. Dr. Brown commented:

“Any one of them individually I think you could dismiss, but when you take it all together, I think the preponderance of the evidence is there is a much higher number of these tens-of-meters-size objects.”

With that in mind, University of Hawaii astronomers are setting up telescopes to scan the sky for quick-moving spots of light that could indicate incoming asteroids. Using a $5 million grant from NASA, the telescopes would give officials enough time to warn and evacuate areas where the asteroid could hit.

[Image vy Alex Alishevskikh via Wikimedia Commons]