Planetary defense is a field of study that focuses on developing strategies and technologies to protect Earth from potential threats posed by asteroids and other celestial objects that could impact the planet. This includes identifying and tracking near-Earth objects, assessing their potential impact risks, and developing methods to deflect or destroy them if necessary. Planetary defense also involves international collaboration and coordination to enhance our ability to detect and respond to potential threats in a timely and effective manner. Ultimately, the goal of planetary defense is to safeguard the Earth and its inhabitants from catastrophic asteroid impacts.