Final answer:
Astronomers use telescopes and radars to assess the risk of NEOs striking Earth. Current efforts have not identified any Nears on a collision course, and detection initiatives like Nasa Spaceguard Survey help monitor and plan for planetary defense.
Step-by-step explanation:
The current danger Earth faces from NEOs (Near-Earth Objects) is actively assessed by astronomers. Utilizing powerful telescopes and radars, astronomers track the trajectories of NEAs (Near-Earth Asteroids) to gauge their risk of impacting the Earth. Through initiatives such as NASA's Spaceguard Survey, astronomers aim to discover and catalog most large Earth-approaching asteroids, specifically those greater than 1 kilometer in diameter, due to their potential to cause global damage in the event of an impact. As of current knowledge, none of the discovered NEAs pose an immediate threat to Earth.Thanks to the efforts started in the 1990s and heightened international involvement, the potential impact hazard is being carefully monitored. The detection and tracking of NEAs is crucial as it allows for potential defensive measures to be planned should an asteroid be found on a collision course with Earth. With continuous surveys and improved detection technology, astronomers are better equipped to find potential threats with enough lead time to consider planetary defense strategies such as deflection.