Asteroid 2012 DA14 came within 27,000 kilometers (17,200) of Earth at 1924 GMT Friday, just hours after nearly 1,000 people were injured when a meteorite exploded over Russia's Ural Mountains.

The asteroid hurtled past at 28,100 kph (17,460 mph), according to NASA, which said the blast in Russia had nothing to do with DA14.

No object the size of DA14, weighing roughly 140,000 tons, has ever come so close to Earth in the more than 50 years NASA has been tracking asteroids.

At its closest approach, 2012 DA14 was well inside the orbits of geosynchronous satellites.

"Asteroids and meteorites contain materials very different from those of the Earth," University of Michigan professor Joel Blum told Efe. "They are the building blocks of the universe."

Blum has studied past impacts of meteorites and asteroids, including that of a rock 10 kilometers (6 miles) wide that slammed into Mexico's Yucatan Peninsula, an event many scientists blame for the extinction of the dinosaurs.

NASA's Near-Earth Object Program Office has been tracking DA14 since it was discovered a year ago by scientists at La Sagra Observatory in Spain. EFE