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1 .This is Scientific American's 60-Second Space. I'm John Matson. Got a minute?
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2 .Since that meteor streaked through Russian skies on February 15th a lot of people have been thinking about asteroid defense.
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3 .If an inbound space rock were discovered early enough, a spacecraft could divert it any number of ways:
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4 .by nuking it, smashing into it or tugging it off course.
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5 .Then there's an idea advocated by aerospace engineer David Hyland of Texas A&M University:
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6 .just spray a coat of paint on the asteroid and let the sun do the rest.
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7 .The proposal relies on the so-called Yarkovsky effect.
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8 .The hottest part of an asteroid--where it's afternoon, asteroid local time--radiates the most heat into space,
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9 .and those thermal photons impart a gentle recoil force.
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10 .It's incredibly subtle, but it's constant,
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11 .so the Yarkovsky effect can significantly change an asteroid's orbit over time.
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12 .A new study in the journal Icarus identifies more than 20 asteroids that have been noticeably shifted by the Yarkovsky effect, naturally.
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13 .Paint would enhance or reduce the effect by changing an inbound asteroid's reflectance, thereby steering it away from us.
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14 .Currently no asteroids that we know of present a real threat to Earth.
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15 .But it's good to be prepared.
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16 .Ask the dinosaurs.
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17 .Thanks for the minute, for Scientific American's 60-Second Space. I'm John Matson.
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