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Zippy Planets

June 28, 2012

Shooting through space on planet Earth is the astronomical equivalent of a carnival ride. Our planet zips around the Sun at about 67,000 miles an hour. And the entire solar system zips around the center of the galaxy at close to a half-million miles an hour.

But if Earth is the equivalent of a carnival ride, then some other planets in the galaxy may be the equivalent of NASCAR, racing through space at breakneck speed.

Astronomers from Dartmouth and Harvard recently calculated what might happen to planets in binary systems that passed close to the supermassive black hole at the center of the galaxy. And none of the results were good news for inhabitants of such planets.

At the right distance, the binary system would be split apart. One of the star systems could be ingested by the black hole or settle into orbit around it, with the other kicked away from the black hole.

Even for the survivor, though, the outlook is bleak. The planet could be hurled into its star or ripped apart by the black hole’s gravity. The planet also could be stripped from the star and sent hurtling into space on its own. And even in the best-case scenario, the star and planet would stay together, but they’d be slung away at tens of millions of miles per hour — a few percent of the speed of light. That snap acceleration would be highly unpleasant for anything that had managed to survive in the deadly environment around a black hole.


Script by Damond Benningfield, Copyright 2012


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