A graduate student at the Massachusetts Institute of Technology Department of Aeronautics and Astronautics has devised a new method of deflecting Earth-approaching asteroids. Previous work has shown that an asteroid might be deflected by a swarm of smart pebbles. MIT’s Sung Wook Paek has expanded on that idea by replacing the pebbles with paintballs.


Asteroids are normally dark in color. Painting an asteroid white would alter the albedo, or reflectivity, of the asteroid. That, in turn, would alter the tiny, but measurable, thrust which sunlight imparts on the asteroid. Over a long period of time, that change in thrust could produce a significant change in the asteroid’s trajectory. A warning time of approximately 20 years would be required for this method to work.

Paek’s paper won the 2012 Move an Asteroid Technical Paper Competition sponsored by the United Nations’ Space Generation Advisory Council.

Paek used the asteroid Apophis as a theoretical test case. Paek determined that five tons of paint would be required to cover the 1,480-foot asteroid. He used the asteroid’s period of rotation to determine the timing of pellets, launching a first round to cover one side of the asteroid and a second round to cover the back side. As the pellets hit the asteroid’s surface, they would burst, splattering the space rock with a 5-micrometer-layer of paint.


Written by Astro1 on October 27th, 2012 , Planetary Defense

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