Earth had another close shave with an asteroid this January. For the second time this month, a previously undetected space rock hurled by close to our planet at a distance 30 percent closer to our planet than the moon.

Asteroid 2017 BX

The extraterrestrial rock, which scientists did not know would pass by our planet a week ago, was only seen on Jan. 20. Dubbed Asteroid 2017 BX, the rocky body came close to our planet within a distance of 162,252 miles, which is just a little over two thirds of the Earth's distance from the moon, when the body passed by Tuesday evening.

Nicknamed "Rerun," the asteroid is about the size of a bus. The Slooh Observatory was able to capture a faint image of the passing space rock, which NASA estimates to be about 28 feet wide.

"Asteroid 2017 BX, nicknamed Rerun in honor of the beloved, late actor Fred Berry, will make its close approach just before midnight Eastern on Tuesday night," Slooh said in a statement announcing the fly-by.

Second Near Miss This Month

Rerun flew by our planet just a few weeks after another previously undetected asteroid passed by Earth. Dubbed 2017 AG13, the asteroid flew by within about 26,000 miles from Earth.

The near-Earth object was discovered two days before it flew by by the Catalina Sky Survey of the University of Arizona.

Rerun is smaller than 2017 AG13, which NASA estimated to be between 36 and 111 feet. 2017 AG13 was about the same size as the asteroid that struck Chelyabinsk, Russia. Rerun also moved slower. 2017 AG13 flew by at a speed of 9.9 miles per second while Rerun passed by at a speed of 4.62 miles per second.

Flyby Of Undetected Space Rocks

The flyby of two previously undetected space objects raises concern particularly because they passed by at a relatively short distance from our planet.

Fear for space objects colliding with Earth is not unfounded. The prehistoric extinction of the dinosaurs are widely attributed to a giant asteroid that struck Earth thousands of years ago.

Scientists, however, said that most of the large asteroids that can cause global catastrophe if they were to hit Earth have already been discovered and none so far appears to pose any threat in the near future. NASA said that the risk of potentially catastrophic asteroids colliding with Earth over the next century is less than 0.01 percent.

NASA Identifies Importance Of Identifying Space Objects That Fly By Earth

The U.S. space agency nonetheless recognizes the importance of identifying asteroids that pass by our planet and is already making necessary preparations in case a hazardous asteroid is on its way to slamming into Earth.

NASA, for instance, established the Planetary Defense Coordination Office (PDCO) program to supervise all projects that detect, track and identify potentially dangerous space objects that pass near our planet's orbit

"NASA's long-term planetary defense goals include developing technology and techniques for deflecting or redirecting objects that are determined to be on an impact course with Earth," NASA said in a statement.