The SD220 will be 1.6 km away and only 2.9 million kilometers will be close to astronomical standards.
It rotates once every 12 days for a asteroid slowly and it pushes.
NASA says it is unusual among the nearest planet asteroids, known as the "non-core axis" rotation, at least about the shortest axis.
Asteroid images were taken by the radar.
In 2003, the final SD220 was fly-by 2015, over 10 million miles (Christmas Time) at NZ time.
According to the Purdue University Impact Calculator, hippo-shaped rock could have created a crater about 22 kilometers in length when it hit the ground with an angle of 45 degrees.