Harvard-Smithsonian Center for Astrophysics

Pipeline for Identifying Potentially Hazardous Asteroids

Potentially hazardous objects (PHOs) are currently defined based on parameters that measure the object's potential to make threatening and close approaches to the Earth. To be considered a PHO, objects generally have an Earth minimum orbit intersection distance (MOID) of 0.05 AU or less and an absolute magnitude (H) of 22.0 or brighter (a rough indicator of large size).