Mile-Wide ‘Walnut’ Asteroid With Its Own Moon To Fly By Earth Saturday

(CBS Local) — An asteroid nearly a mile wide with a moon of its own is expected to pass by Earth on Saturday, traveling at 48,000 mph.
The unnamed space rock designated as Asteroid (66391) 1999 KW4 is actually a double asteroid or a binary asteroid. That means it’s composed of one large asteroid orbited by a smaller moon. In this case, it’s about a third of a mile wide and orbits around the larger body about once every 16 hours.
The Las Cumbres Observatory describes 1999 KW4 as