What are odds an asteroid will level a major city? Higher than you might think, say researchers.
New data released by a nonprofit asteroid-watcher reveals that large meteor impacts are not particularly rare.
This image provided by NASA/JPL-Caltech shows a simulation of asteroid 2012 DA14 approaching from the south as it passes through the Earth-moon system on Friday, Feb. 15, 2013. The 150-foot object will pass within 17,000 miles of the Earth. NASA scientists insist there is absolutely no chance of a collision as it passes.
NASA/JPL-Caltech/AP Photo
The chances of an asteroid hitting the Earth and causing significant damage are much higher than what was previously estimated.
According to new data released by the B612 Foundation, a non-profit group that aims to launch its Sentinel Space Telescope in 2018 in order to map locations and paths of dangerous asteroids, between 2000 and 2013 some 26 explosions on Earth ranging in energy from 1 to 600 kilotons were caused by asteroids.
"We can expect a multi-megaton asteroid impact (large enough to destroy a major city should it hit one) about every hundred years," according to the Foundation's website. "These impacts were heard using large listening stations that pick up the low frequency infrasound pulse from the explosions." Peter Brown, a planetary scientist at the University of Western Ontario in London, Canada, provided data for the video.
Packed with tremendous energy, these “city-killer-size” asteroids are much more powerful than the 15-kiloton atom bomb that devastated Hiroshima.
"While most large asteroids with the potential to destroy an entire country or continent have been detected, less than 10,000 of the more than a million dangerous asteroids with the potential to destroy an entire major metropolitan area have been found by all existing space or terrestrially-operated observatories," said Ed Lu, former US Shuttle and Soyuz astronaut and co-founder and CEO of the B612 Foundation, in a press release.
He added, “Because we don’t know where or when the next major impact will occur, the only thing preventing a catastrophe from a "city-killer" sized asteroid has been blind luck."
Most of the meteors detected exploded at high altitude, causing no damage on Earth.
But not all of them. In February 2013, a meteor strike over the city of Chelyabinsk in Russia injured more than 1,200.
According to NASA, anything bigger than one to two kilometers across could have "worldwide effects." Ceres, the largest resident of the asteroid belt between Mars and Jupiter, is about 950 kilometers across.
NASA is currently developing an Asteroid Redirect Mission (ARM) "to identify, capture and redirect an asteroid to a safe orbit of Earth's moon for future exploration by astronauts in the 2020s."