2001 YB₅

2001 YB₅ is a sub-kilometer asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group that passed at a nominal distance of 0.0043767 AU (654,750 km; 406,840 mi) from the Moon and 0.0055633 AU (832,260 km; 517,140 mi) from Earth on 7 January 2002.[1]

The asteroid measures approximately 300 meters in diameter; insignificant enough in size to be only discovered later that year in 26 December 2002 by NASA's Near-Earth Asteroid Tracking program (NEAT).[2][3][4] The nearest proximity it has reached Earth by was 830,000 kilometres which is approximately twice the distance to the Moon.[4] Based on limited observations, the asteroid may have a 2.5 hour rotation period and a Minimum Orbit Intersection Distance (MOID) from the Earth of 0.0038 AU (570,000 km; 350,000 mi).[1] The findings of David Morrison of the NASA Ames Research Center claim that although YB5-sized objects in space commonly fly and orbit the Earth's proximity at such close distances annually, there are no indications of a YB5 collision on Earth as their predicted impact spans from about once every 20,000 to 30,000 years.[4]