19172001

19172001 is a notable astronomical event that occurred on December 20, 2001. It refers to the close approach of the asteroid 2001 YB5 to Earth. The asteroid, estimated to be between 1.1 and 2.5 kilometers in diameter, passed within approximately 550,000 kilometers of Earth, which is about 1.4 times the distance from Earth to the Moon. This event was significant because it was one of the closest known approaches of a large asteroid to Earth in recent history. The asteroid was discovered by the Near-Earth Asteroid Tracking (NEAT) project at the Palomar Observatory in California on December 18, 2001. The close approach of 2001 YB5 provided an opportunity for astronomers to study the asteroid's composition and trajectory, contributing to the understanding of near-Earth objects and their potential impact hazards. The event also highlighted the importance of ongoing efforts to detect and track potentially hazardous asteroids.