It was first discovered on February 23 1950. It was observed for 17 days and then faded from view for half a century. Then, an object discovered on December 31, 2000 (originally named 2000YK66) was recognized as being the long-lost 1950 DA.
Radar observations were made at Goldstone and Arecibo, Puerto Rico on 3-7 March 2001, during the asteroid's 7.8 million km approach to the Earth (a distance 21 times larger than that separating the Earth and Moon). Radar echoes revealed a slightly asymmetrical spheroid with a mean diameter of 1.1 km. Optical observations showed the asteroid rotated once every 2.1 hours, the second fastest spin rate ever observed for an asteroid its size.
Due to its relatively fast spin, it is thought to be fairly dense. If it continues on its present orbit, it will approach near to the Earth on March 16 2880, with the probability of impact being 1/300. The energy released by a collision with 1950DA would cause an extinction event, and destroy most life on the planet.
Since the re-discovery of 1950DA, scientists have been considering various asteroid deflection strategies.