The asteroid is set to whiz past Earth Feb. 15, and will come within 17,200 miles of the planet when it makes its cosmic fly by.
"Since regular sky surveys began in the 1990s, we've never seen an object this big get so close to Earth."
Discovered last year by an amateur team of astronomers at the La Sagra Sky Survey observatory in Spain, the asteroid measures roughly 164 feet across. Yeomans emphasized that while the approach of 2012 DA14 will bring it closer than the geosynchronous satellites orbiting 22,245 miles above Earth, there's no real threat of the asteroid colliding with the planet.
Earth comes into "close" contact with such asteroids about every 50 years, and is only hit by them every 1,200 years, Yeomans estimated.
NASA officials explained asteroid 2012 DA14 is roughly the same size as the object that exploded in the atmosphere above Siberia in 1908, which leveled hundreds of square miles in what scientists refer to as the "Tunguska Event."
An asteroid about the same size as 2012 DA14 slammed into the Earth 50,000 years ago, creating the famous Meteor Crater in Arizona, Yeomans said.
The agency will use its Goldstone radar in California's Mojave Desert to follow the asteroid from Feb. 16 to Feb. 20.
Scientists say asteroid 2012 DA14 will arrive like a bullet train. The object will be traveling so fast that only the most experienced astronomers are likely to see it as it whizzes by the planet.
"The asteroid will be racing across the sky, moving almost a full degree (or twice the width of a full moon) every minute," Yeomans said. "That's going to be hard to track."