On July 23, 2017, astronomers detected a small asteroid now designated Asteroid 2017 001, three days after it passed by at 1/3 the moon’s distance from the Earth.
It was detected from the ATLAS-MLO telescope at Mauna Loa, Hawaii. After a trajectory analysis, it was revealed that it had been closest to the Earth on July 20 sometime between 10:27 p.m. to 11:32 p.m. EDT.
(between 02:27 to 03:32 UTC on July 21)
Even though it was considered that Asteroid 2017 001 passed us at a safe distance, the fact that stands out is that it is about three times as big as the house-sized asteroid that exploded over Chelyabinsk, Russia in February, 2013, breaking windows in six Russian cities and causing 1,000 people to seek treatment for injuries mostly from flying glass.
Also, Asteroid 2017-001 was traveling at 11,369mph, and the scary part is that it was detected three days after passing the Earth at such a close distance.
Check out: Close shave from an undetected asteroid