Planetary Defense in the Age of DART

Planetary Defense is the applied science of defending against hazardous asteroid or comet impacts on Earth. It involves a multidisciplinary approach to detecting, tracking, and cataloging such objects; assessing their potential to impact the Earth and cause harm; developing space flight systems to rapidly reconnoiter potentially hazardous objects and prevent Earth impacts when possible; and creating infrastructure both nationally and internationally for effectively executing Planetary Defense, to include emergency disaster response on the ground in the aftermath of an impact.

In this talk, I will describe the current assessment of the asteroid and comet impact hazard, along with current and planned systems for conducting Planetary Defense, including detection and tracking, in-space reconnaissance, deflection/disruption of asteroids and comets, and plans for developing overall Planetary Defense infrastructure. Techniques and technologies for deflection and disruption of hazardous objects will be discussed, including kinetic impactors and nuclear explosive devices.

Additionally, I will provide an overview of NASA’s recent Double Asteroid Redirection Test (DART) mission, which launched in November 21, 2021 and succeeded in impacting the asteroid Dimorphos, the smaller secondary member of the Didymos binary asteroid system, on September 26, 2022. DART was humanity’s first in-space test of an asteroid deflection system and reduced the originally nearly 12-hour period of Dimorphos’ orbit around Didymos by approximately 33 minutes. I will present and discuss the key results from the DART mission, including our assessment of the momentum enhancement factor associated with DART’s impact on Dimorphos, which is a key result for planning future Planetary Defense missions involving kinetic impactors.