An asteroid set to skim past Earth at a distance of 6,880km on October 12 will be used as a test for NASA's ability to track incoming space rocks. The space agency says the asteroid, called 2012 TC4, "will come no closer than 4,200 miles (6,800 kilometers) from the surface of the Earth" and there's no chance of a direct hit. It measures, at most, up to 30 meters across - similar in size to the asteroid that hit Chelyabinsk in Russia in 2013.
In astronomical terms it's very close indeed and the right kind of distance to test out NASA's tracking and observational abilities. “Scientists have always appreciated knowing when an asteroid will make a close approach to and safely pass the Earth because they can make preparations to collect data to characterize and learn as much as possible about it,” said Michael Kelley, program scientist and NASA Headquarters lead for the TC4 observation campaign.
"This time we are adding in another layer of effort, using this asteroid flyby to test the worldwide asteroid detection and tracking network, assessing our capability to work together in response to finding a potential real asteroid threat.” Current knowledge on this particular asteroid is sparse - it was only studied for seven days following its initial discovery in 2012. NASA says it has been too distant and too faint to track over the last five years. But in October, large telescopes will be focused on it to reestablish its trajectory and orbit.