Fifth Interagency Planetary Defense Tabletop Exercise focused on an asteroid impact scenario proposed by NASA’s JPL Center for Near-Earth Object Studies.
A large asteroid impact on Earth is highly unlikely in the foreseeable future. But because the damage from such an event could be great, NASA conducts hypothetical “tabletop” asteroid impact exercises every two years with experts and decision-makers from federal and international agencies to address the many uncertainties of an impact scenario. The last exercise took place in April this year and the preliminary report was issued on 20 June.
Making such a scenario realistic and useful for all involved is no small task. Scientists at the Center for Near-Earth Object Studies (CNEOS) at NASA’s Jet Propulsion Laboratory in Southern California, which specializes in tracking and orbiting asteroids and comets and determining whether any pose a threat to Earth, played a major role in the design. these exercises from the first 11 years.
“These hypothetical scenarios are complex and require significant effort to design, so our goal is to make them useful and challenging for exercise participants and decision makers to refine their processes and procedures to quickly arrive at an action plan while addressing the gaps on the planet . knowledge of the defense community,” said JPL’s Paul Chodas, director of CNEOS.
This year’s scenario: A hypothetical asteroid perhaps a few hundred yards across has been discovered, with an estimated 72% chance of hitting Earth in 14 years. Potential impact sites include densely populated areas in North America, southern Europe and northern Africa, but there is still a 28% chance the asteroid will miss Earth. After several months of observation, the asteroid moves too close to the Sun, making further observations impossible for another seven months. Decision makers need to figure out what to do.
The exercise was led by NASA’s Planetary Defense Coordination Office (PDCO), the Federal Emergency Management Agency’s Directorate of Emergency Response, and the Department of State’s Office of Space Affairs. Over two days in April, participants gathered at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, which hosted the event, to consider potential national and global responses to the scenario.
“This was a very successful tabletop exercise with nearly 100 participants from US government agencies and, for the first time, international planetary defense experts,” said APL’s Terik Daly, who coordinated the exercise. “An asteroid impact would have serious national and international consequences, so if this scenario were to actually play out, we would need international cooperation.”
In real life, CNEOS calculates the orbit of every known near-Earth object to provide an assessment of future potential impact hazards in support of NASA’s planetary defense program. To make this scenario realistic, the CNEOS team simulated all the observations in the months leading up to the exercises and used orbit determination calculations to simulate the probability of an impact.
“At this point, an impact was likely but not yet certain, and there were significant uncertainties about the size of the object and the location of the impact,” said Davide Farnocchia, a navigation engineer at JPL and CNEOS who led the asteroid design. circulate. “It was interesting to see how it affected the decision-makers and how the international community might respond to a real threat 14 years later.”
Preparation, planning and decision-making have been key points in all five exercises that have taken place over the past 11 years. For example, could a survey spacecraft be sent to an asteroid to gather more data about its orbit and better determine its size and mass? Would it also be possible to try to deflect an asteroid so that it misses Earth? The viability of this method was recently demonstrated by NASA’s Double Asteroid Redirection Test (DART), which struck the moon asteroid Dimorphos on September 26, 2022 and slightly altered its trajectory. Other methods of deflection were also considered during the exercise.
However, any deviation or exploratory mission would require many years of preparation, requiring the use of advanced observatories capable of finding dangerous asteroids as soon as possible. One such observatory is the NASA Near-Earth Object Surveyor, or NEO Surveyor. Managed by JPL and scheduled to launch in late 2027, the infrared space telescope will detect bright and dark asteroids, including those orbiting near the Sun. In doing so, NEO Surveyor will support PDCO’s goals of detecting hazardous asteroids as soon as possible to allow more time to launch a deflection mission to potential threats.
To find out the outcome of the exercise, read NASA’s preliminary summary.
For more information about CNEOS, visit:
https://cneos.jpl.nasa.gov/
Ian J. O’Neill
Jet Propulsion Laboratory, Pasadena, California.
818-354-2649
ian.j.oneill@jpl.nasa.gov
Karen Fox / Charles Blue
NASA headquarters
202-358-1600 / 202-802-5345
karen.c.fox@nasa.gov / charles.e.blue@nasa.gov
2024-095