Giant umbrella tethered to asteroid could help fight climate change, says scientist

As the world continues to grapple with the devastating effects of climate change, scientists are exploring every possible mitigation option. This last idea may seem wild, but it’s not out of the ordinary. Astronomer István Szapudi of the University of Hawaii’s Institute of Astronomy has proposed catching an asteroid, parking it in front of Earth and tying an umbrella to it to block out some of the sunlight.

The concept of a solar shield is not new, but Sapudi’s modifications could significantly reduce the cost and complexity of its implementation, bringing us another step closer to achieving this ambitious goal. The solar shield would block out a small percentage of the sunlight that constantly irradiates the Earth, allowing us to counter rising temperatures and giving us time to find other solutions.

The difficulty with this idea is that the sail would have to have a significant mass as ballast to keep it from being blown away by solar wind and radiation pressure, as well as to provide gravitational stability. It would be difficult and expensive to get such mass into space. However, if the mass is already there, capturing an asteroid and strapping an umbrella to it could be a solution.

Sapudi calculated that placing the counterweight toward the Sun in the L1 Lagrangian would reduce the total mass of the shield and counterweight to only 3.5 million tons. The L1 Lagrangian is the point of relative gravitational stability resulting from the interaction between the Earth and the Sun. The gravitational attraction of the two bodies is balanced at these Lagrangian points, minimizing the amount of corrections needed to stay at that point.

While 3.5 million tons may seem like a large mass, it is about 100 times less than previous estimates for an untethered shield. Only 1% of this mass would be the shield itself, about 35,000 tons, with the rest of the mass coming from the asteroid. It is possible to further reduce the mass of the shield by using lighter materials such as graphene. However, the maximum payload capacity of modern rockets is nowhere near 35,000 tons.

NASA has shown that we can redirect an asteroid, but a lot more work needs to be done to make this idea a reality. Sapudi believes that if research and development starts now, it may be possible to realize the idea before it’s too late for the climate. There are other potential benefits, such as resource extraction on the asteroid.

While this idea may seem far-fetched, it is important to explore all options in the fight against climate change. As the planet warms at an alarming rate, we need to take bold and innovative steps to protect our planet.

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