Sorry if already discussed. - Greg GEOENGINEERING: Scientists suggest deploying asteroid dust to cool the planet
Published: Tuesday, October 2, 2012 A group of Scottish scientists suggests that dust from an asteroid, suspended in space, could block incoming sunlight and help to cool the Earth. Russell Bewick of the University of Strathclyde in Scotland said, "We can buy time to find a lasting solution to combat Earth's climate change. The dust cloud is not a permanent cure, but it could offset the effects of climate change for a given time to allow slow-acting measures like carbon capture to take effect." Bewick proposes to suspend a large asteroid within the Lagrange point L1, where the gravitational pull of the Earth and the sun cancel each other out. A device consisting of electromagnets, called a "mass driver," would hurl dust away from the asteroid's surface. The device would work to propel the asteroid into the L1 point as well as generate the dust. The researchers say the largest near-Earth asteroid, 1036 Ganymed, could generate a dust cloud dense enough to block 6.58 percent of incoming solar radiation. The cloud would be about 11 million-billion pounds in mass and about 1,600 miles wide. A main challenge would be pushing an asteroid the size of Ganymed to the L1 point. "The company Planetary Resources recently announced their intention to mine asteroids," Bewick said. "The study that they base their plans on reckons that it will be possible to capture an asteroid with a mass of 500,000 kilograms [1.1 million pounds] by 2025. Comparing this to the mass of Ganymed makes the task of capturing it seem unfeasible, at least in everything except the very far term. However, smaller asteroids could be moved and clustered at the first Lagrange point." Safety is also a concern, Bewick said. He added, "On the global scale, it is not possible to test because the test would essentially be the real thing, except probably in a diluted form. Climate modeling can be performed, but without some large-scale testing, the results from these models cannot be fully verified." The group will publish its findings in the Nov. 12 issue of the journal Advances in Space Research(Charles Choi, LiveScience<http://www.livescience.com/23553-asteroid-dust-geoenineering-global-warming.html>, Sept. 28). -- RE -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
