Asteroid to pass inside moon's orbit, help scientists calibrate tracking technology

Oct. 11 (UPI) -- An asteroid will pass within 26,000 miles of Earth, well inside the moon's orbit, over the course of late Wednesday night and early Thursday morning.

The closest approach of 2012 TC4 will occur above Antarctica at 1:42 a.m. EDT. The space rock, measuring between 50 and 100 feet in width, will pass within just a few thousand miles of Earth's most distant satellites, which orbit the planet at 22,000 miles.

The Panoramic Survey Telescope and Rapid Response System first identified the asteroid in 2012. At the time, asteroid trackers predicted the that 2012 TC4 would return for a flyby in the fall of 2017. Their calculations were correct.

In July of this year, the asteroid came back into the view of the European Southern Observatory. Since then, researchers have been tracking its path toward Earth.

And while scientists are certain the asteroid will pass at a safe distance, astronomers are always looking to improve their asteroid tracking technologies. Tonight's flyby offers them a chance to do so.

"This encounter with TC4 is being used by asteroid trackers around the world to test their ability to operate as a coordinated international asteroid warning network," NASA wrote in a news release.

As 2012 TC4 makes its approach, dozens of telescopes will be tracking its movements, observing the space rock in a wide spectrum of wavelengths, from visible to near-infrared to radar

"[This] is an exercise to test how well a diverse group of observatories can be brought together in a time frame appropriate for recovering and characterizing an asteroid that might present a danger to Earth," Mike Kelley, NASA scientist and leader of the tracking effort, told UPI in an email earlier this year.

While NASA and its Near Earth Object Observation program are responsible for funding and organizing much of the asteroid tracking effort, space agencies and academic institutions from all over the globe will be watching and observing 2012 TC4.

As of now, no asteroid is expected to cross paths with Earth in the next 100 years, but scientists are constantly discovering new chucks of space debris and recalibrating the orbital paths of known rocks. Each new flyby offers the chance improve tracking models.

While 2012 TC4 wouldn't likely survive the trip through Earth's atmosphere, an asteroid doesn't have to be massive to do serious damage. Anything larger than a half mile in diameter is capable of doing catastrophic damage should it collide with Earth.

And as 2013's Chelyabinsk meteor proved, an asteroid doesn't have to make direct contact with Earth's surface to do considerable damage.

The Chelyabinsk meteor, which became a fireball brighter than the sun, a superbolide, as it entered Earth's atmosphere above Russia, exploded 19 miles above Russia's Chelyabinsk Oblast region with the force of 500,000 tons of TNT. The shockwave broke thousands of windows and sent hundreds of people to the hospital.