The Near Earth Asteroid Tracking program discovered near-Earth asteroid 1997 WU22 in November of 1997. This follow up movie of the 1997 WU22 was taken with the Palomar 200-inch telescope in California. To find asteroids, the telescope tracks the stars, which appear stationary; the asteroid in this case moves from upper right to lower left and is easy to spot with computers or human observers.

Source: NASA