Small changes in Apophis' path that could make the difference between a hit or a miss are possible, according to Jon Giorgini, a planetary analyst in NASA's Jet Propulsion Laboratory in Pasadena, Calif.

"We have not eliminated the threat in 2036,'' Lindley Johnson, the manager of NASA's asteroid detection program, told the committee.

(The committees) task is to review various methods that have been proposed to deflect or destroy an incoming asteroid and recommend the best options. They include a nuclear bomb, conventional explosives or a spacecraft that would push or pull the asteroid off its course.

Offbeat ideas are painting the surface of the asteroid so that the sun's rays would heat it differently and alter its direction, and a ``gravity tractor, ''a satellite that would fly close to the asteroid, gently nudging it aside.

So far, NASA has spent $41 million on asteroid detection and deflection, but the Near Earth Object Program is running out of money.

"It's just barely hanging on,'' Shapiro said.

That seems like money well spent.