An asteroid more than one and a half miles long is due to zoom past Earth later - from a far-off distance.
The big rock called Asteroid 1998 QE2 will keep a safe distance of 3.6 million miles, or 15 times the distance between Earth and the moon. You will not be able to see it without a powerful telescope.
It is believed to be about 1.7 miles long, or about nine times the length of the Queen Elizabeth 2 cruise ship. But that has nothing to do with its name. The letters and number in the name represent the timing and sequence of the asteroid's discovery in 1998.
Astronomers getting their first close-up glimpse of the giant asteroid found a surprise bonus rock.
A smaller moon asteroid is circling the larger space rock, an unusual but not unheard of space phenomenon.
The smaller rock was discovered on Wednesday night by astronomers using radar to look at QE2.
The moon asteroid is about 2,000 feet wide. That's about average for such near-Earth objects.