Asteroid Impacts, A Risk For Humanity
A giant space rack hurtles toward us, turning into a fireball before slamming into our planet’s surface. Every animal, plant or building within a few hundred kilometres is vaporised by thousands of degrees of intense heat generated on impact. Earthquakes, storms and tsunamis then batter areas further away. The worst, though, is yet to come: the enormous impact – not to mention the fires it creates worldwide – will throw so many particles into the air that the dust will block out the Sun.
Kiss goodbye to growing food for at least a decade. This has happened many times throughout Earth’s history, most famously 65.5 million years ago, when an asteroid over 10km wide hit Chicxulub in Mexico, an event that killed the dinosaurs.
Anywhere within a few thousand kilometres of the impact site would suffer from the resulting shock waves, debris and devastating earthquakes. Outside this ‘kill zone’, you might be protected from the immediate effects. Shelter will help people survive an impact.
So you’ll be glad to hear that NASA has been watching out for huge, potentially world-ending space rocks for some time now. To date, NASA has identified 94% of all nearby objects more than 1km wide, and almost 40% of those over 140m have also been discovered.
CAN WE SURVIVE?
Could we do anything about a giant on a collision course with Earth? One solution is to ram it with high-velocity spacecraft well in advance which could change the asteroid’s spacecraft and trajectory by a small – but large enough amount.
If there was an asteroid on its way your best bet is to watch your Twitter and check websites for the latest info on where the space rock will strike. You’ll then be in with a chance of catching a plane the other side of the planet. Otherwise, find yourself a cave or nuclear bunker to hope for the best. And make sure you take food supplies to last until the dust clouds clear.
Given NASA’s tracking of near-Earth and other astronomical surveys, the chances of dying in a humanity-ending asteroid are very low – around one in 4.3 million. For comparison, your chance of dying in an aeroplane accident are around one in 30,000; falling foul of a fatal road accident is one in 90. Nonetheless, mankind might have to bat away a giant space rocks one day: an asteroid the size of the one that wiped dinosaurs hits Earth fairly regularly, every 100 million years.
But assuming that we’re still around when a giant space rock next slams into the Earth, take heart from the fact that it wouldn’t take many of us to repopulate the planet – a human population could recover even if it were only cut to only a couple of hundred individuals.