Planetary Defense Coordination Office
Planetary Defense at NASA
Near-Earth objects (NEOs) are asteroids and comets that orbit the Sun like the planets, but their orbits can bring them into Earth’s neighborhood – within 30 million miles of Earth’s orbit. Planetary defense is “applied planetary science” to address the NEO impact hazard.
NASA established the Planetary Defense Coordination Office (PDCO) to manage its ongoing mission of planetary defense. The PDCO:
Provides early detection of potentially hazardous objects (PHOs) – the subset of NEOs whose orbits predict they will come within 5 million miles of Earth’s orbit; and of a size large enough (30 to 50 meters) to damage Earth’s surface;
Tracks and characterizes PHO’s and issues warnings of the possible effects of potential impacts;
Studies strategies and technologies for mitigating PHO impacts; and
Plays a lead role in coordinating U.S. government planning for response to an actual impact threat.
To continue reading this page, please click the following link:
To watch the DART impact event Sept. 26, 2022, go here: