2001 YB5 is an Apollonear-Earth asteroid that passed 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 2002-Jan-07. The asteroid was approximately 300 meters in diameter; insignificant enough in size to be only discovered later that year in December 26, 2002 by NASA's Near-Earth Asteroid Tracking program (NEAT). The nearest proximity it has reached Earth by was 830,000 kilometres which is approximately twice the distance to the Moon. 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). 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.