An occultation occurs when one celestial object passes directly in front of another from an observer's perspective, temporarily blocking or "hiding" the background object. This astronomical event creates a dramatic cosmic game of hide-and-seek that provides valuable scientific opportunities.</p><p>The most familiar occultations involve the Moon passing in front of stars or planets. When our Moon occults a bright star, the star vanishes instantly rather than gradually dimming—a phenomenon that helped early astronomers prove stars are point sources of light. Lunar occultations of planets are particularly spectacular; Jupiter's four largest moons regularly occult each other, with events lasting several minutes.</p><p>Solar eclipses represent the most famous occultations, where the Moon blocks the Sun for up to 7.5 minutes. These events have shaped human history, from ancient civilizations interpreting them as omens to Edmund Halley using the 1715 eclipse to map England's coastline with unprecedented accuracy.</p><p>Modern astronomers use occultations as precise measuring tools. When asteroids occult distant stars, the brief interruptions—sometimes lasting mere seconds—reveal asteroid sizes, shapes, and even detect previously unknown moons. The technique is so sensitive that coordinated observations across multiple locations can measure asteroid diameters to within kilometers. Professional and amateur astronomers worldwide collaborate on these "stellar occultation" campaigns, making occultations one of astronomy's most democratically accessible research methods.