Protecting Earth: Gravitational tractor could lure asteroids off course
By Ron Cowen
When a wayward asteroid is about to smash into Earth, scriptwriters for the movie Armageddon called in Bruce Willis to drill into the rock and nuke it. He succeeds but sacrifices his own life.
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Now, two NASA scientists, both also astronauts, suggest a simpler, safer, and much more plausible way of diverting an offending asteroid. Their method relies on the gravitational tug of a massive, unmanned spacecraft to pull the rock away from a damaging rendezvous with Earth.