WASHINGTON — About midafternoon Friday (Eastern time), a 160-foot asteroid known as 2012 DA14 will whip by the Earth, 17,000 miles (27,000 kilometers) above the Earth's surface. The asteroid poses no danger to anyone — its trajectory is well known, and it will miss the Earth. But it "poses no danger" in the same way that a gun fired a half-inch above your head does. If you were absolutely certain of the trajectory of the bullet and knew that it wouldn't hurt anyone else nearby, and there was nothing you could to stop it anyway, you could be comfortable in the knowledge that it would not affect you at all.
But it doesn't make much sense to ignore the shot entirely.
Impacts of large asteroids on Earth are rare. Asteroids the size of Friday's would cause only localized damage. The orbits of larger objects are better known, and so imminent danger of mass extinction is low. It is unlikely that astronomers will soon discover a "potentially hazardous asteroid" (PHA) high on what astronomers have dubbed the Torino scale. Still, NASA is not doing nearly enough to prepare for that unlikely eventuality.
What should be NASA's most important task — keeping the Earth, and America, safe from asteroid and comet impact — is barely mentioned in its latest strategic plan, released earlier this week. Planning for a mission to deflect a potential cataclysm is left to private organizations like the B612 Foundation, in which a number of engineers and scientists with years of experience with NASA are involved. It's even headed by former astronaut Ed Lu. But this is too important a task to be left to philanthropists and retirees like the B612 crowd. However laudable their efforts, they lack the resources and capability that the government has. Keeping its citizens safe is the foundational responsibility of government. And in this respect, NASA has been heedless of its responsibilities.