Potentially hazardous asteroid
A Potentially Hazardous Asteroid (PHA) is a Near-Earth asteroid that can come very close to the Earth and is big enough to cause at least a region-wide catastrophe if it were to hit the Earth. An asteroid is considered a PHA if its Earth MOID (Minimum Orbit Intersection Distance) is less than 0.05au and its absolute magnitude is greater than 22. By this definition, PHAs are usually bigger than 150m.
| The Minor Planets |
| Vulcanoids | Main belt | Groups and Families | Near-Earth objects | Jupiter Trojans |
| Centaurs | Trans-Neptunians | Damocloids | Comets | Kuiper belt | Oort cloud |
| (For other objects and regions, see: Binary asteroids, Asteroid moons and the Solar system) |
| (For a complete listing, see: List of asteroids. For pronunciation, see: Pronunciation of asteroid names.) |
Categories: Asteroid groups and families | Asteroid stubs