Space and Physics

Earth-Sized Magnetic Shield Could Save Us From Superflares


Jonathan O'Callaghan

Senior Staff Writer

clockOct 3 2017, 14:56 UTC

A large coronal mass ejection could devastate life on Earth. Pixus/Shutterstock

At some point in the future, Earth may be hit by a giant solar flare from the Sun that fries many of our electronics at huge financial cost. Now, two astronomers have proposed building a giant structure in space to save us from such an eventuality.


A paper from Manasvi Lingam and Avi Loeb describing the idea is available on arXiv. It details sending a magnetic shield to Lagrange point 1 (L1), a gravitationally stable region between Earth and the Sun, to deflect incoming solar flares or supposed superflares.

In particular, the duo references the famous Carrington event of 1859, when a solar flare hit Earth with so much power it caused telegraph lines to catch fire. Were such an event to happen again, our increased reliance on technology would make the losses enormous.

“The cumulative worldwide economic losses [from a powerful flare] could reach up to $10 trillion dollars, and a full recovery is expected to take several years,” the duo wrote.

So their proposal is to build this giant structure, which would cost about $100 billion. While the cost is high, comparable to building the International Space Station, they note it is much less than the financial cost of a flare hitting Earth. They propose building it within 150 years.

The shield would deflect solar particles around Earth. Lingam/Loeb

The shield would basically be a huge loop of 1 centimeter-thick copper wire, roughly the size of Earth, and weighing 90 million kilograms (198 million pounds). The scientists don’t provide too many details on actually building it, other than noting that we could use asteroids to get the necessary materials for it in space.

They also note that we might not be the only intelligent race to consider protection from solar flares. In the search for extraterrestrial intelligence (SETI), Lingam and Loeb suggest that other civilizations may have built similar structures to protect themselves from flares, and it might be possible to spot them.

“It seems reasonable to conclude that technologically advanced civilizations on planets orbiting these stars would be well aware of the economic and biological risks posed by flares and superflares,” they wrote.


Not everyone is on board with the idea, however. Anders Sandberg, a research fellow who works out of Oxford University’s Future of Humanity Institute, told Gizmodo he was not convinced by the economic model.

“There seemed to be far too many arbitrary assumptions,” he said. “In particular, the vulnerability of the world economy can both increase and decrease, for example, if we build a more modularized and resilient power grid.” 

Space and Physics
  • earth,

  • sun,

  • solar flare,

  • carrington event,

  • magnetic shield