Asteroid impact poses a real risk to life on Earth, with the lack of recent collisions being simply blind luck.
Since 2001, there have been 26 atomic-bomb scale impacts from asteroids on the planet Earth, ranging in energy from 1 to 600 kilotons.
For perspective, the bomb that destroyed Hiroshima in 1945 was 15 kilotons – the meteor that injured over a thousand in Chelyabinsk, Russia in 2013 was over 20 kilotons — some calculations say equivalent to 30 Hiroshima sized bombs.
This amount is three to 10 times more frequent than was previously believed, meaning that these undetected and undeterred collisions have only missed populous areas by chance.
A video by the B612 Foundation’s asteroid surveying Sentinel Mission visualizes the last decade’s impact data, which shows that though most asteroids were too small to cause large-scale damage, our current inability to predict major impacts is a dangerous blind spot.
Mapping asteroid impact
This interactive map by mapping service CartoDB using data compiled by The Guardian’s Simon Rogers shows the extensive breadth of asteroid impact on land in recorded history.
As you can see, the United States is a bit of a hot spot — though the time spans thousands of years, and water impacts are not included.
This is just to say that meteors and asteroids are not at all uncommon. And though since 71% of Earth’s surface is water, most have landed in the sea, being caught off guard is the last thing anyone wants when it’s headed toward a city and too late to stop.
Of course, not all asteroids are dangerous, as many dissolve in the atmosphere before hitting Earth.
According to a NASA report, 556 asteroids the size of a washing machine or larger collided with the Earth in the last 20 years, but only one per 5,000 years is likely to cause significant damage.
Others are even smaller — for example, a woman named Ann Hodges was hit by a softball-sized meteorite in her living room in 1945, and it only bruised her thigh (she had to fight with her landlady for the right to keep it.)
Most small asteroids are shielded by the Earth’s atmosphere.[contextly_sidebar id=”vqQwpbQO67mXAl3lP0iGWwrLxHmSrcwU”]
Ann Hodges’ is a rare case – – you’re statistically more likely to be hit by both a tornado and lightening than a meteor. But it does goes to show that anything is possible. Just recently, an enormous meteor called UR116 was spotted by Moscow University’s robotic telescope MASTER, and which would be catastrophic if it hit.
Detecting incoming meteors and preventing an asteroid impact
How do you detect asteroids? And if necessary, how do you stop them?
NASA is planning a future robotic space system that can eventually redirect asteroids, while Russia is making plans to use cold-war era missiles to blow asteroids out of the sky. But before an asteroid can be being destroyed or deflected it must first be spotted and tracked. That’s where two former astronauts come in.
The B612 Foundation, started by former NASA astronauts Ed Lu and Rusty Schweickart, is dedicated to detecting and tracking asteroids in order to protect humankind – and the planet – from the fate the dinosaurs suffered.
In partnership with Ball Aerospace, B612 is building a Sentinel Space Telescope, which will locate and catalog hundreds of thousands of NEAs (near earth asteroids), collecting and transmitting data from infrared observations while orbiting the Earth.
Though the telescope will take about four years to build and test, it is expected that after 6.5 years of use up to 98% of NEAs will be detected.
The technology is readily available to deflect problematic meteors – a series of spacecraft slams would do the trick, Ed Lu says – but the real challenge is getting to them decades before they hit.
The B612 Foundation is a private organization, but NASA has a NEO (Near-Earth Object) Program and Asteroid Redirect Mission (ARM) as well. ARM even seeks to capture an asteroid and redirect it to Earth rotation for further studies.
But despite a deadline set by Congress in 2005, NASA says budget cuts will set back a close-to-complete discovery of asteroids until 2030 – and that since the NEO mission is not their main priority, money should be “poured” elsewhere.
Russia To The Rescue?
Russia has proposed a program by which nuclear missiles mounted on Inter-Continental Ballistic Missiles (ICBMs) would be used against incoming asteroids to change their earth-bound trajectory or just blast them from the sky. However, plans to deploy nuclear weapons space may make some military strategists very uncomfortable, as such weapons might also be used to target objects on earth.
NASA’s Asteroid Redirect Mission (ARM) uses a more refined approach to asteroids, envisioning a robotic system that can intersect with an approaching asteroid and simply nudge it off its path towards earth to prevent an asteroid impact.