Should a huge space-rock ever threaten the very existence of Earth, don’t panic! NASA has a plan to save us…
It was 66 million years ago that the dinosaurs’ reign on Earth came to an end. The instigator was an asteroid, a large lump of space rock of around ten kilometres (six miles) in diameter, which struck the Earth with a force that’s one billion times greater than the Hiroshima bomb. Today, the destruction is evident in the form of the Chicxulub impact crater in Mexico, approximately 20 kilometres (12 miles) deep, by 180 kilometres (112 miles) wide.
With asteroids tumbling through the Solar System and some coming close to our planet, it’s only a matter of time until we end up with the same fate as the dinosaurs. That’s why we have to act fast in getting rid of a potentially hazardous asteroid before it gets to us. The solution? NASA’s Hypervelocity Asteroid Intercept Vehicle, or HAIV for short, which works by blasting an Earth-bound chunk of rock to smithereens with the help of a nuclear bomb.
HAIV will be coupled with an asteroid warning system – even if there’s less than a week until we’re hit by an asteroid, HAIV can still be used, meaning that it’s never too late to protect our planet. The spacecraft will be launched to rendezvous with the target asteroid. It will then use an impactor to carve out a crater and, only a millisecond behind, a bomb follows to fit inside the pre-drilled hole. The bomb then detonates, shattering the asteroid into millions of tiny pieces.
Depending on how close the devastated asteroid is to Earth, it’s thought that the fragments could still hit our planet in the form of an intense meteor shower. However, provided that the fragments were small enough, we would be largely unaffected as they would burn up in our atmosphere.
The wake-up call
It was the fireball that exploded over Chelyabinsk in Russia on the morning of 15 February 2013, that further highlighted the need for an asteroid protection program, which includes the likes of the Hypervelocity Asteroid Intercept Vehicle. With some eyewitnesses claiming that they felt intense heat from the meteor, which was brighter than the Sun and had 20 to 30 times more energy than that released by the Hiroshima bomb when it exploded, the lump of space debris injured around 1,500 people and damaged over 7,000 buildings. Small fragmentary meteorites that survived the blast were found later, along with a six-metre (20-foot) wide hole on Lake Chebarkul’s frozen surface.
Article originally appeared in How It Works Issue 77. How It Works is available from all good retailers, or you can order it online from the ImagineShop or download the digital version onto your iOS or Android device. To make sure you never miss an issue of How It Works magazine, make sure you subscribe today!