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It’s so bonkers you could assume it’s just the plot of an upcoming Hollywood blockbuster.
But scientists are really toying with the idea of capturing an asteroid, in the name of saving the planet from climate change.
The bizarre mission, if ever given permission, would then see a huge umbrella sticking atop the trapped rock to shield Earth from the sun’s rays.
István Szapudi, an astronomer from the University of Hawai’i, argued that his far-fetched concept was just a huge “sun shield.”
The shield – which would be made of the ultra-tough “wonder material” graphene – would block energy from the sun and cool our planet.
István Szapudi, an astronomer at the University of Hawai’i, proposes tethering a massive “sun shield” to an asteroid in space
Artist’s impression of the system: the asteroid, lower left, tethers the triangular sun shield, which blocks sunlight
The academic has laid out his silly idea in a new paper, published in Proceedings of the National Academy of Sciences.
Like sitting under an umbrella in warm weather, the space shield would cool the Earth, but without plunging us into the next ice age.
“In Hawai’i, many use an umbrella to block the sunlight when walking around during the day,” Szapudi said.
“I was thinking, can we do the same for the Earth and mitigate the looming catastrophe of climate change?”
The “sunscreen” concept has been proposed before, most notably in a recent study that suggested using moon dust as a sunlight blocker.
Other studies have suggested using a physical man-made shield that acts as an umbrella – much like Szapudi’s idea.
But according to the academic, no one has yet discussed how such an object could feasibly be launched into space and remain in place once there.
Even if a rocket could launch the multi-billion-ton sun shield, it could potentially be blown out of position by powerful solar radiation.
And the lighter the shield is to get it into space, the more likely it is to blow up once there.
He proposes stationing the device at the ‘L1’ Lagrange point – a position in space between Earth and the sun where objects sent there tend to stay there.
But even then, solar radiation can blow away a light sunscreen.
Studies have already suggested using a physical man-made shield that acts as an umbrella
Szapudi therefore proposes using an asteroid as a counterweight, which would be attached to the sun shield via a chain.
Importantly, the counterweight of the asteroid would give the device enough weight to keep it from blowing away.
But it would also reduce the total mass launched from Earth, meaning a launch of the device would be much more feasible.
According to Szapudi, the weight of the shield and counterweight together would be about 3.5 million tons, about 100 times lighter than previous estimates for an untethered shield.
While this number is still well above current launch capabilities, only 1 percent of its weight — about 35,000 tons — would be the shield itself, and that’s the only part that needs to be launched from Earth.
The remaining 99 percent would be the asteroid it’s attached to.
Szapudi admits that the shield is “heavy enough to wreak havoc” if it accidentally crashes to Earth, and emphasizes the importance of the chains.
“If several ropes hold the shield, breaking one or two wouldn’t cause accidents,” he said.
“When there are only two ropes left, the shield automatically turns away from the sun’s rays (like a sail when the rigging breaks), and the counterweight pulls the structure safely towards the sun.
“In the worst case, the structure would be lost, but the security threat to the Earth is negligible.”
According to Szapudi, there are “various scenarios” about how the asteroid would be captured and attached.
“My favorite would be to attach the shield to a suitable asteroid that needs minimal orbital manipulation, and use the shield itself as a solar sail, propelling the whole system into position,” he told MailOnline.
Making an asteroid perform a ‘slingshot’ maneuver with Earth could get us farther from the sun, scientist suggests (file photo)
To build the shield, the expert suggests using graphene – a sheet form of carbon that is only one atom thick but incredibly strong.
The price of graphene is falling and could drop to $1 per square foot within a decade, meaning the structure could be built “soon.”
While the idea seems unlikely, engineering studies using this approach could begin now to create a workable design that could mitigate climate change within decades.
In his paper, he warns that climate change poses “an imminent threat to the way of life of a significant portion of humanity.”
“Sustainable research and development must start now to produce a technical solution as an insurance policy in time,” the newspaper reads.
“A tethered shield can always be deployed if other efforts to combat climate change fail.”