Spray-Painting Asteroids Could Protect Earth from Space Rock Threat

Near-earth asteroid art
An artist's illustration of an asteroid flying near Earth.
(Image credit: Texas A&M University)

One form of action could involve dusting a threatening asteroid with a thin coat of paint. The paint would change the amount of sunlight reflected by the space rock, potentially nudging it away from Earth through the accumulated push provided by many thermal photons as they radiate from the asteroid's surface. (This force is called the Yarkovsky effect, after the Russian engineer who first described it around the turn of the 20th century.) [Photos: Asteroids in Deep Space]

The scheme would use powdered paint, which the sun's rays would then cure into a smooth coating. The paint would probably have to be applied long before any potential impact — years or decades, perhaps — to give the Yarkovsky effect enough time to make a difference.

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Mike Wall
Space.com Senior Writer
Michael was a science writer for the Idaho National Laboratory and has been an intern at Wired.com, The Salinas Californian newspaper, and the SLAC National Accelerator Laboratory. He has also worked as a herpetologist and wildlife biologist. He has a Ph.D. in evolutionary biology from the University of Sydney, Australia, a bachelor's degree from the University of Arizona, and a graduate certificate in science writing from the University of California, Santa Cruz.