That asteroid, estimated to be at least 3,600 feet and bigger than any building in the world, will come within 1.2 million miles of Earth on Jan.
2003 SD220: 2,595 feet, will be 3.4 million miles away from Earth on Dec.2017 AE3: 393 feet, will be 2.2 million miles away from Earth on Dec.2016 TR54: 380 feet, will be 4 million miles away from Earth on Dec.