Warehouse-sized asteroid sneaks up on Earth by hiding near the sun - CNET
A space rock possibly as wide as a football field flew between the moon and Earth last week, but the big asteroid -- catalogued as 2021 SG -- wasn't spotted until the day after it had already made its closest pass by our planet.While asteroid 2021 SG is safely heading back to deeper space, it provides a brief moment of deja vu for sky watchers who may remember the large bolide that went unseen until it exploded in 2013 above Chelyabinsk, Russia. .That meteor was estimated to be only about one quarter the diameter of 2021 SG, and yet that was large enough to create a shock wave that blew out thousands of windows in the city below, injuring hundreds.