On Friday, an asteroid about half the size of a football field will zip past Earth.

And it will be close, according to experts. Then again, in outer space, close is a relative term.

In this case, it’s about 17,200 miles.

The asteroid, assigned the name 2012 DA14, will pass closer to Earth than many of the orbiting satellites we launch.

“It’s the closest approach for an object this size or larger,” said Don Yeomans, the manager of NASA’s Near Earth Object Program in Pasadena, Calif.