2003 SD220 is a large asteroid that passed by Earth on 24 December 2015. This image from NASA’s 230-foot (70-meter) Deep Space Network antenna at Goldstone, California on 22 December 2015.
The 2.4 km / 1.5 mile long asteroid passed just 11 million km / 6.8 million miles which is pretty close in astronomic terms. It will pass even closer in 2018 when it will be just 2.8 million km / 1.8 million miles away.
This second radar image was taken on 17 December 2015 when the asteroid was 12 million km / 7.3 million miles away.