Asteroid Size of Empire State Building Is About to Fly By Earth

An asteroid as big as a skyscraper will pass within 1.7 million miles of Earth on Friday. But it's not on a collision course with us, as it will pass seven times the distance from Earth to the moon, per the AP. NASA's Center for Near-Earth Object Studies estimates the space rock is between 690 feet and 1,575 feet across. That means the asteroid could be similar in size to New York City's Empire State Building or Chicago's Willis Tower.

Discovered in 2008, the asteroid is designated as 2008 OS7. It won't be back our way again until 2032, but it will be a much more distant encounter, staying 45 million miles away. The harmless flyby is one of several encounters this week. Three much smaller asteroids also will harmlessly buzz Earth on Friday, each no more than tens of yards across, with another two on Saturday. On Sunday, an asteroid roughly half the size of 2008 0S7 will swing by, staying 4.5 million miles away.

Live Science notes this is the closest that 2008 OS7 has come to Earth in more than a century, and it's not set to get this close again for several more. Per Business Insider, the "city killer" asteroid will be too tiny to see with the human eye as it whizzes past, but the Virtual Telescope Project will host a 45-minute livestream showing the celestial event starting at around 1pm ET. (More asteroid stories.)