Only in space would 2 million miles be considered a close call . An asteroid with an estimated diameter of three football fields zoomed by Earth late Monday , missing our home by about that distance . It traveled at some 27,000 miles per hour . The asteroid came just about a year after a relatively small asteroid blew up over Russia . The roughly 60-foot space rock plunged into Earth 's atmosphere and exploded over the city of Chelyabinsk with the force of about 30 early nuclear bombs . The blast left more than 1,500 injured , mostly by glass from shattered windows , and raised concerns about humanity 's vulnerability to stray asteroids . `` On a practical level , a previously unknown , undiscovered asteroid seems to hit our planet and cause damage or injury once a century or so , as we witnessed on June 20 , 1908 , and February 15 , 2013 , '' said Bob Berman , Slooh host and astronomer . Slooh.com tracks potentially hazardous objects , like asteroids and comets . Berman added : `` Every few centuries , an even more massive asteroid strikes us -- fortunately usually impacting in an ocean or wasteland such as Antarctica . `` But the ongoing threat , and the fact that biosphere-altering events remain a real if small annual possibility , suggests that discovering and tracking all NEOs ( near-Earth objects ) , as well as setting up contingency plans for deflecting them on short notice should the need arise , would be a wise use of resources . '' Study : Solar system full of 'rogue ' asteroids .
The asteroid misses Earth by some 2 million miles . It comes just about a year after an asteroid blew up over Russia . Comment: