WATCH ABOVE: B612 animation illustrating frequency of asteroids exploding in Earth’s atmosphere
TORONTO – An asteroid-hunting non-profit group has released an animation showing asteroids striking Earth with more frequency than previously believed.
The B612 Foundation, founded by former NASA astronauts and scientists, released an animation of the strikes detected by Nuclear Test-Ban Treaty Organization instruments.
Twenty-six explosions were recorded between 2000 and 2013 using these infrasound instruments. These explosions are inaudible to the human ear.
These weren’t nuclear explosions, but rather intense explosions caused by asteroids exploding in Earth’s atmosphere.
The data used for this video was first collected by Peter Brown, Professor of Physics and Astronomy at Western University. The research was published in the scientific journal Nature in November 2013.
Many may remember the meteor that exploded over Chelyabinsk, Russia, on February 13, 2013. That meteor, estimated to be 19 metres in diameter, sent a shockwave throughout the town, blowing out windows and injuring thousands.
But, Brown said, “The 26 they’re talking about, none of those, including Chelyabinsk, were city-killers or city-destroyers. They’re just too small.”
“The key point, when I look at that video, what it tells me is that the Earth’s atmosphere is an extremely effective shield for all but the very largest events, and none of the events that we saw really made it to the ground,” Brown said. “And the reason these events were detected, because the shockwaves were so prominent in the atmosphere, was because all of their energy was deposited in the upper atmosphere, and that’s good news.”
B612 has plans to build the Sentinel Space Telescope Mission, an early-warning infrared telescope that would detect potentially hazardous near-Earth asteroids. It would be the first publicly funded telescope of its kind.
“I think Sentinel will do great things for discovering lots of asteroids,” said Brown. But, he said, “Sentinel is not going to solve the issue of finding all the 50-metre-size asteroids because there are probably on order of hundreds of thousands…of these objects.”
Brown said that the odds of something like Chelyabinsk hitting close enough to a place on Earth that has windows is only once every 3,000 years. In fact, he said, the chance of something like Chelyabinsk hitting a major urban area is even less: once every 20,000 years.
Asked if he loses any sleep over the threat of asteroids, Brown said, “Nope. In fact, 20 years ago I would have been more concerned about it. Now, because we really have a pretty good census of all the big asteroids, which are the ones to worry about, I sleep much more soundly at night.
“We have to put the risk into context. Hurricanes and earthquakes are far more damaging on typical lifetime scales that humans deal with than asteroid impacts.”