When a massive asteroid exploded over Chelyabinsk, Russia last year, it was a jarring wake-up call to us all about the dangers of these impacts, but in many cases, the prevailing opinion is that these events are rare. However, according to new research, that asteroid was just one of over two dozen large impacts that our planet has suffered since the year 2000, and it is only by pure luck that we have escaped disaster.
The above video gives a visualization of the research of Peter Brown, a professor at the University of Western Ontario that studies meteors and comets, using data from the Comprehensive Nuclear Test-Ban Treaty Organization. This data came from a network put into place to monitor the atmosphere for 'infrasound' signals due to nuclear weapon tests. Besides three claimed nuclear weapon tests by North Korea, there hasn't been any such tests since 1998. However, this infrasound network has picked up 26 different explosions in the atmosphere since August 2000 that can't be accounted for by nuclear explosions. They were asteroid impacts; the weakest of these was the equivalent of a 1 kiloton nuclear bomb, while the most powerful was around 600 kilotons.
Of all of them, the Chelyabinsk superbolide is probably the most well-known, but besides four or five others — especially in the Mediterranean Sea in June 2002, over New South Wales in Nov. 2005, over Indonesia in Oct. 2009 and in California and Nevada in April of 2012 — the rest went completely unnoticed except by these infrasound detectors. This has easily supported the idea among the public that these impacts are rare, but in fact, that's just not so.
"This shows that asteroid impacts are NOT rare — but actually 3-10 times more common than we previously thought," Dr. Ed Lu, the co-founder & CEO of the B612 Foundation, said in a statement. "The fact that none of these asteroid impacts shown in the video was detected in advance shows that the only thing preventing a catastrophe from a 'city-killer' sized asteroid is blind luck."
Also, there are a lot of asteroids and meteoroids flying around out there, as the video below shows, but we still haven't found them all.
[ More Geekquinox: Laser shot at the Blood Moon reveals the source of the Full Moon Curse ]
These facts are pretty scary, when you consider it all. However, rather than being meant to simply scare us, the purpose of Dr. Lu and the rest of the B612 Foundation bringing this to our attention is to inspire us to action. They want to put a $250 million infrared telescope — appropriately named Sentinel — out into space, to find these asteroids and meteoroids, and give us the fair warning we need to protect the planet. NASA has its own satellite for this purpose, now called NEOWISE. However, being in Earth orbit, there is a very large 'blind spot' in its view, because NEOWISE can't look towards the sun. That's the direction the Chelyabinsk asteroid came from as it hurtled towards us. Sentinel will be set up in roughly the same orbit as the planet Venus, looking outward towards Earth's orbit, to catch these kinds of asteroids as they fly past.
This is going to take money, of course. B612 Foundation is a non-profit organization that depends on donations, for the most part. Their hope is that the rest of the world will see the importance of the Sentinel mission, and realize just how inexpensive the mission is, especially when you compare its price-tag to the loss of life and material damage that would result from an asteroid destroying a city.
With the chaotic interplanetary shooting gallery that Earth is flying through, it was only a matter of time before we witnessed an event like the asteroid explosion over Chelyabinsk, and it's also only a matter of time before we see something worse. It may be today, or it may be 100 years from now, and we have many ideas for how to deflect these objects, but the key to protecting ourselves is knowing about them ahead of time.
(Videos courtesy: D Josh Rosen/B612 Foundation)
Geek out with the latest in science and weather.
Follow @ygeekquinox on Twitter!