The PDCO sponsors projects through its Near-Earth Object (NEO) Observations Program that employ a variety of ground and space based telescopes to search for NEOs, determine their orbits, and measure their physical characteristics. NASA is developing the NEO Surveyor space telescope optimized for NEO search and characterization to accelerate the discovery of the currently undetected NEOs.

The PDCO works with other government agencies to develop and update a National NEO Preparedness Strategy and Action Plan. The PDCO also provides expert input on the nature and effects of asteroid impacts to the Federal Emergency Management Agency (FEMA), so that adequate emergency response can be prepared in the event of a PHO impact that is not possible to avoid.

The PDCO also coordinates efforts with the space agencies of other nations as a member of the multinational International Asteroid Warning Network and the Space Missions Planning Advisory Group, under the endorsement of the United Nations Committee on the Peaceful Uses of Outer Space. NASA reorganized its Near Earth Object Observations Program and established a Planetary Defense Coordination Office in January 2016 in response to the NASA Office of Inspector General’s 2014 report, “NASA’s Efforts to Identify Near-Earth Objects and Mitigate Hazards.”

DART is the first-ever mission dedicated to investigating and demonstrating one method of asteroid deflection by changing an asteroid’s motion in space through kinetic impact. This method will have DART deliberately collide with a target asteroid—which poses no threat to Earth— in order to change its speed and path. DART’s target is the binary, near-Earth asteroid system Didymos, composed of the roughly 780-meter (2,560-foot) -diameter “Didymos” and the smaller, approximately 160-meter (530-foot)-size “Dimorphos,” which orbits Didymos. DART will impact Dimorphos to change its orbit within the binary system, and the DART Investigation Team will compare the results of DART’s kinetic impact with Dimorphos to highly detailed computer simulations of kinetic impacts on asteroids. Doing so will evaluate the effectiveness of this mitigation approach and assess how best to apply it to future planetary defense scenarios, as well as how accurate the computer simulations are and how well they reflect the behavior of a real asteroid.

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The current congressionally directed objective of the NEO Observations Program is to find, track, and characterize at least 90 percent of the predicted number of NEOs that are 140 meters and larger in size–larger than a small football stadium–and to characterize a subset representative of the entire population. Objects of this size and larger pose a risk to Earth of greatest concern due to the level of devastation an impact would cause, and should continue to be the focus of global search efforts. While no known asteroid larger than 140 meters in size has a significant chance to hit Earth for the next 100 years, less than half of the estimated 25,000 NEOs that are 140 meters and larger in size have been found to date.

The Center for Near-Earth Object Studies (CNEOS) computes high-precision orbit paths for NEOs from positions reported to the Minor Planet Center. CNEOS computes orbits for new asteroid discoveries and performs long-term analyses of possible future positions of hazardous asteroids relative to Earth to determine and warn of any impact hazard. CNEOS computes impact time and location in the event of a predicted impact. The Jet Propulsion Laboratory hosts CNEOS for the NEO Observations Program, and its website makes all orbit computation public.