An asteroid as big as a 10-story building has passed by Earth at a distance half that of the Moon, researchers have revealed. The asteroid, dubbed 2017 AG13, was only spotted on Saturday by the University of Arizona’s Catalina Sky Survey. It is between 50 and 111 feet long, and when it passed by Earth, 2017 AG3 was moving at 9.9 miles per second. According to an asteroid-impact simulator called Impact Earth! by Purdue University, if a porous rock asteroid of 111 feet long hit Earth at a 45-degree angle, the simulator found, it would have exploded as an air burst. The site says the blast would have released about 700 kilotons’ worth of energy — dozens of times more powerful than the atomic bomb detonated over Hiroshima. However, since it would have occurred from a distance of about 10 miles high, it probably wouldn’t have had much effect on the ground; if anything, a high-altitude boom may have sounded as loud as heavy traffic on the ground.
Photo Credits – Feature: NASA via Business Insider. Map: University of Arizona via Daily Mail