Planetary defense is the practical work of finding asteroids and comets near Earth, calculating where they are going, communicating risk clearly, and preparing response options before a real threat becomes urgent.
Planetary defense protects Earth from natural impact hazards. It combines sky surveys, observatories, orbital calculations, spacecraft engineering, public communication, and emergency planning.
The goal is not fear. The goal is time: time to confirm the science, time to warn correctly, and time to act if action is ever needed.
Most near-Earth object passes are routine scientific events. Risk depends on size, distance, speed, uncertainty, and probability — not just whether an object appears in a close-approach list.
Survey telescopes and observers detect a moving object against the background stars.
Additional observations reduce uncertainty and help confirm that the object is real.
Scientists calculate the object's path and compare future close approaches with Earth.
Distance, size, velocity, and probability determine whether the event is routine or needs attention.
Public updates should be sourced, calm, and separated from official emergency instructions.
If evidence warrants it, options can include more tracking, spacecraft missions, deflection studies, or civil preparedness.
Use official sources first. TESS pages are public education and mission-support summaries, not official emergency orders.