Asteroid Coming Closer to Earth Than Any Before – Without Hitting It

An asteroid large enough to destroy a major U.S. city is expected to whiz past the Earth the day after Valentine's Day, coming closer to hitting the planet than any object of its size before, experts say. Of course, they're not counting those that have actually slammed into Earth.

Known as 2012 DA14, the asteroid has a 148-foot diameter and the mass equivalent of a cruise ship, the Christian Science Monitor reports.

Though it is not the largest asteroid that scientists have ever seen, the 2012 DA14's size is similar to another asteroid that exploded over Siberia in 1908 and flattened 80 million trees.

When it is closest to the Earth on Feb. 15, the asteroid will be about 17,000 miles from the Earth's surface, which is 5,000 miles below the altitude that most major weather and communications satellites operate.

While the asteroid will approach the Earth, astronomers have adamantly declared that there is no chance it will strike the planet.

"Its orbit is very well-known. We know exactly where it's going to go, and it cannot hit the Earth," Don Yeomans, a NASA specialist for near-Earth objects, told CNN.

Paul Chodas and Don Yeomans, astronomers at NASA's Jet Propulsion Laboratory, said that on average asteroids of this size come this close to Earth once every 40 or so years and collide with the planet once every 1,200 years.

A team of amateur astronomers in Spain discovered the 2012 DA14 last February.

"These small objects can appear at any moment," Jaime Nomen, a Barcelona dental surgeon who led the team, told CNN.

Nomen said his team routinely hunts for small objects in the orbit that might not appear until weeks before they approach.

Comprised of stone rather than metal or ice, the asteroid will pass by the earth at an even closer distance in 2110, at which point there will still be a small chance the object will hit the planet, astronomers say.

This isn't the first asteroid to make headlines in recent months.

In early December, a 3-mile-wide asteroid passed the earth at a distance of approximately 4.3 million miles. If it collided with the Earth, scientists say the impact could have killed off the human race, just as scientists hypothesize a 6-mile-wide asteroid decimated dinosaurs 65 million years ago.