IN THE sci-fi comedy “Don’t Look Up”, humanity has just six months to avert the destruction of Earth by a 10-kilometre wide asteroid.
The movie satirises the global response to climate change, but it raises the question: Would we survive if we spotted a planet-killer at the last minute?
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In a recent study, scientists at the University of California analysed how mankind might swerve extinction-by-asteroid.
Just like the plot of the Netflix hit, they gave their hypothetical protagonists just half a year’s notice before an impact by a 10km comet.
The team concluded that the best means of survival would involve training thousands of the world’s nukes at it – and crossing our fingers.
“Our reason for writing the paper was to ask: ‘Could one prevent a catastrophe of this nature’,” lead author Philip Lubin, a professor of physics at UC Santa Barbara, told The Sun.
“It’s a serious attempt to look at whether humanity has reached a point where we could prevent what happened to the dinosaurs 65million years ago.”
In the paper, published last week on the Arxiv database, Prof. Lubin and a colleague first analyse the impact that such a collision would have on Earth.
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A 10km asteroid would likely wipe out almost all life on our planet, causing the temperature of our atmosphere to rocket to 300C.
Given a timescale of several years, Nasa’s preferred method to avert such a catastrophe involves using a spacecraft to deflect the incoming object.
However, diverting a rock of planet-killing size with a few months’ notice simply wouldn’t be possible, Prof. Lubin says.
His analysis shows that the only viable option in that scenario would be a nuclear strike.
“What we point out is that we easily possess enough nuclear devices to take apart a large object like the one in ‘Don’t Look Up’,” Prof. Lubin told The Sun.
“Our nuclear arsenals are designed to essentially threaten other nations – but those same devices could be used to protect us.”
The paper suggests that it would be possible to “take apart” the object with a thousand javelin-shaped “penetrators” loaded with nuclear warheads – less than 10 per cent of the world’s current arsenal.
They could be launched on one of two deep-space rockets currently under development: SpaceX’s Starship and Nasa’s Space Launch System (SLS).
Both spacecraft are still in development but are due to liftoff on their first spaceflights in the coming months.
The explosions would peel away layers of the space rock like an onion, breaking it into smaller parts.
There’s just one problem: The blasts would lead to the creation of radioactive debris that would then rain down on Earth.
While it’s a grim scenario, it’s far better than simply accepting our fate at the hands of an enormous space rock, Prof. Lubin says.
“In the case of a 10km asteroid, you’re talking about an existential threat that’s going to kill billions of people,” he explained.
“You can say ‘but, I’m really worried about the radiation [created by a nuclear defence strategy]’, but also just die.”
Earth’s last major extinction event was the asteroid that wiped out the dinosaurs.
It’s believed to have measured about 12 km across and obliterated up to 80 per cent of all life on Earth.
Since then, our planet has been battered by a number of smaller, unwelcome celestial guests – including the Chelyabinsk meteor.
At just 20 metres wide, the space rock injured 1,500 people and smashed the windows of 7,000 buildings when it exploded over central Russia in 2013.
Prof. Lubin says that, given the frequency with which the Earth is hit by space rocks, we need strategies in place to deal with whatever’s thrown at us.
“It’s the nature of our natural world that we get hit by comets and asteroids because there are many around,” he said.
“There are big things out there that, if they did hit us, it would be catastrophic.
“On the other hand, there are a lot of smaller things out there, some of which are of similar size to the Chelyabinsk meteor, which are not existential threats, but they could potentially kill a lot of people.”
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In other news, a four-tonne chunk of a SpaceX rocket is on a collision course with the Moon, according to online space junk trackers.
Boeing has sunk $450million into a flying taxi startup that hopes to whisk passengers across cities by the end of the decade.
Personalised smart guns, which can be fired only by verified users, may finally become available to U.S. consumers this year.
And, scientists are embarking on a mission to unravel the mystery behind dozens of grisly child mummies buried in an underground tomb in Sicily.
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This post first appeared on Thesun.co.uk
