Last week Asteroid 1998 QE2 flew within 5.8M km of Earth. The asteroid which was 2.7km in diameter was so massive that NASA observations revealed it had its own tiny moon. While QE2 is only ΒΌ the size of the asteroid which is believed to have killed the dinosaurs, scientists believe that, had it impacted Earth, it would have triggered an extinction level event.
Watch a Video of QE2 Moon:
Images and Video Courtesy of NASA