SPACE.com -- Astronomers Gear Up for Historic Asteroid Pass in 2029
...In May, former Apollo astronaut Rusty Schweickart sent a letter to NASA administrator Mike Griffin urging the agency to investigate whether in 2029 Apophis might enter certain gravitational "keyholes" near Earth that would alter the asteroid's flight path in a manner that could put it on a more certain collision course with our planet in 2036...
