A massive asteroid described as roughly a '4 Empire State Buildings wide' object will make its closest approach to Earth this weekend, passing safely by on Saturday morning at a distance of about 1.6 million miles, according to the European Space Agency. The object, known as 1997 NC1, has drawn attention online as it moves past Earth, but space agencies say there is no threat to the planet.
The asteroid was first detected nearly three decades ago by a tracking system in Hawaii, and its orbit has been closely monitored ever since. Its path is well understood, and scientists have long known about this weekend's approach.
