Published on Apr 27, 2019
While headlines routinely report on "close shaves" and "near-misses" when near-Earth objects (NEOs) such as asteroids or comets pass relatively close to Earth, the real work of preparing for the possibility of a NEO impact with Earth goes on mostly out of the public eye. For more than 20 years, NASA and its international partners have been scanning the skies for NEOs, which are asteroids and comets that orbit the Sun and come within 30 million miles (50 million kilometers) of Earth's orbit. International groups, such as NASA's Planetary Defense Coordination Office (PDCO), the European Space Agency's Space Situational Awareness-NEO Segment and the International Asteroid Warning Network (IAWN) have made better communication of the hazards posed by NEOs a top priority. In the spirit of better communication, next week at the 2019 Planetary Defense Conference, NASA's PDCO and other U.S. agencies and space science institutions, along with international partners, will participate in a "tabletop exercise" that will play out a realistic - but fictional - scenario for an asteroid on an impact trajectory with Earth. The scenario begins with the fictional premise that on March 26, astronomers "discovered" a NEO they consider potentially hazardous to Earth. After a "few months" of tracking, observers predict that this NEO - dubbed 2019 PDC - poses a 1 in 100 chance of impact with Earth in 2027 (in real life, the international community has decided that a 1 in 100 chance of impact is the threshold for action). Participants in this exercise will discuss potential preparations for asteroid reconnaissance and deflection missions and planning for mitigation of a potential impact's effects.