"We know today that it will also not hit the Earth in the year 2050, but the close flyby in 2050 might deflect the asteroid such that it could hit the Earth in the year 2079", said Rüdiger Jehn of the European Space Agency's Near-Earth Object programme in the Netherlands.
There was no actual risk of the asteroid hitting home, but it did provide scientists with the opportunity to test NASA's planetary defense systems.
Koschny said one big radar system in Puerto Rico did not work due to damage from Hurricane Maria but that another U.S. based radar system was used instead.
"This campaign is a team effort that involves more than a dozen observatories, universities and labs around the globe so we can collectively learn the strengths and limitations of our near-Earth object observation capabilities", said Dr. Vishnu Reddy, an assistant professor at the University of Arizona's Lunar and Planetary Laboratory, leader of the 2012 TC4 observation campaign.
Dubbed 2012 TC4, the space rock will shave past at an altitude of less than 44,000 kilometres (27,300 miles) - just above the 36,000-km plane at which hundreds of geosynchronous satellites orbit the Earth.
This was about an eighth of the distance between the Earth and the Moon.
"This means it must be very bright", to make it appear bigger, said Koschny. It spins once every 12.2 minutes, Sputnik International reported.More news: Local health group to host drive-thru flu shots
In 2013, a meteor which was about the same size as TC4 exploded in the atmosphere over the city of Chelyabinsk in central Russian Federation with the kinetic energy of about 30 Hiroshima atom bombs.
It the blast damaged many buildings.
The closest approach to Earth occurred over Antarctica at about 1:40 a.m.
Ahead of its approach, scientists had stressed there was no risk of collision from the asteroid.
Still, according to brightness measurements, 2012 TC4 is similar in size (30-100 feet) to the meteor that "caused a shock wave and explosion" in the atmosphere as it passed over Chelyabinsk, Russia, in 2013, EarthSky reported.
As its full name suggests, the asteroid was first spotted five years ago when it called on Earth at about double the distance, before disappearing from view. What made this one special was that it was chosen to test the global warning system. TC4 is the 13th object in space that poses a threat to hit the Earth, the Guardian wrote.