Potentially Hazardous Asteroids
Near-Earth asteroids large enough and close enough to warrant tracking, under the objective PHA criterion — a monitoring category, not a prediction of impact.
One of the most elongated known asteroids, a near-Earth Apollo object well characterised by radar.
CategoryNear-EarthTypeSilicaceous (S)Diameter≈ 5.0 × 2.0 × 2.1 kmDiscovered1951An elongated near-Earth asteroid in a chaotic, tumbling rotation, flown past by China's Chang'e 2 in 2012; it crosses both Earth's and Mars's orbits.
CategoryNear-EarthTypeSilicaceous (S)Diameter≈ 4.75 × 2.4 × 1.95 kmDiscovered1989A near-Earth asteroid famous for its very close but non-impacting approach to Earth on 13 April 2029; impacts for the foreseeable future have been ruled out by radar and tracking.
CategoryNear-EarthTypeSilicaceous (S)Discovered2004- 101955 BennuPHA
A small, carbon-rich near-Earth asteroid sampled by OSIRIS-REx, whose material was returned to Earth in 2023.
CategoryNear-EarthTypeCarbonaceous (C)Diameter490 mDiscovered1999 - 162173 RyuguPHA
A carbonaceous near-Earth asteroid visited by Japan's Hayabusa2, which returned surface and subsurface samples to Earth in 2020.
CategoryNear-EarthTypeCarbonaceous (C)Diameter900 mDiscovered1999