Celestial navigation is the technique of determining one's position on Earth by observing celestial bodies such as the sun, moon, planets, and stars. Historically essential for maritime and aerial navigation, this method uses measurements of angles between celestial objects and the horizon, often with a sextant, combined with precise timekeeping. While less common in modern navigation due to GPS and electronic systems, celestial navigation remains a critical backup skill for navigators in case of technological failure or cyberattacks that compromise digital navigation systems. Understanding celestial navigation enhances resilience against cybersecurity threats targeting GPS and other electronic navigation aids.