NASA Planetary Defense Strategy And Action Plan (Report)
In April 2023 the United States government released the National Preparedness Strategy and Action Plan for Near-Earth Object Hazards and Planetary Defense (National Planetary Defense Strategy) to improve the United States’ preparedness to address the hazard of NEO impacts over a 10-year period, primarily by helping organize and coordinate interagency NEO-related efforts.
The 2023 National Planetary Defense Strategy updates the United States’ first comprehensive Near-Earth Object Preparedness Strategy and Action Plan released in 2018. It builds on existing efforts by Federal Departments and Agencies to address the hazard of NEO impacts, includes evaluation of where progress has been made since 2018, and focuses future work on planetary defense across the U.S. government.
The National Planetary Defense Strategy provides a road map for a collaborative and federally coordinated approach to developing effective technologies, policies, practices, and procedures for decreasing U.S. and global vulnerability to NEO impacts.
When implemented, the National Planetary Defense Strategy will improve detection, research, mission planning, emergency preparedness and response, international engagement, and internal U.S. government coordination on planetary defense.
NEOs are asteroids and comets that come close to or pass across Earth’s orbit around the Sun. They range in size from small “meteoroids” only a few meters across, to much larger bodies several kilometers wide. When NEO orbits bring them into Earth’s atmosphere, smaller objects harmlessly fragment and disintegrate, while larger objects can cause local damage or even global devastation.
The threat exists because our planet orbits the Sun amidst millions of objects that cross our orbit – asteroids and comets. Even a rare interstellar asteroid or comet from outside our solar system can enter Earth’s neighborhood.
Characteristics of the estimated NEO population:
- Around 1,000 NEOs greater than one kilometer in size that are potentially capable of causing global impact effects. Approximately 95 percent of these bodies have been found and none are a current threat.
- Around 25,000 objects larger than 140 meters in size, capable of causing regional devastation, are believed to exist. Less than 50 percent have been detected and tracked to date.
- An estimated 230,000 or more objects exist that are equal to or larger than 50 meters in size and could destroy a concentrated urban area. It is estimated that fewer than eight percent of these have been detected.
- Tens of millions of smaller NEOs exist. While most are small enough to likely break up in Earth’s atmosphere during an impact, those larger than 10 meters in size could potentially cause some surface damage. Less than one percent of these small bodies have been discovered.2
