Closest Flyby of Large Asteroid to be Naked-Eye Visible

The 2029 event will be the closest brush by a good-sized asteroid known to occur. The rock will pass Earth inside the orbits of some satellites. No other asteroid has ever been clearly visible to the unaided eye.
The asteroid is roughly estimated to be a little more than 1,000 feet (320 meters) wide.
The rock, catalogued as 2004 MN4, was discovered last June. It was seen again in December, and for a time scientists said it had the highest odds of hitting Earth ever given to a space rock. Subsequent observations refined the future path and eliminated those odds for the 2029 flyby. It won't hit the Moon, either.