On March 21, 2021, Earth will have its closest encounter with 2001 FO32 — the largest and fastest-known asteroid scheduled to fly past our planet this year. The space rock, estimated to be between 2,526 feet ( 0.47 miles) and 5,577 feet (1.05 miles) in diameter, will zip past Earth at a staggering speed of 76,980 miles per hour (123,887 km/h). To put it in perspective, that is about 100 times faster than the speed of sound!