Apogee

**Apogee** is the point in an orbit around Earth where an object reaches its maximum distance from our planet. Think of it as the "high point" of an elliptical orbital path – when a satellite, spacecraft, or the Moon swings farthest away from Earth before gravity pulls it back closer.</p><p>The Moon provides the most familiar example, reaching apogee at approximately 405,500 kilometers (252,000 miles) from Earth. This distance varies slightly each month, causing the Moon to appear about 14% smaller and 30% dimmer during apogee compared to perigee (its closest approach). The International Space Station experiences apogee at roughly 420 kilometers altitude, while some communication satellites reach apogee distances of over 35,000 kilometers above Earth.</p><p>The term combines the Greek words "apo" (away from) and "gaia" (Earth), coined by astronomers in the 17th century as they developed our understanding of orbital mechanics. Johannes Kepler's laws of planetary motion, established in the early 1600s, explained why orbits are elliptical rather than circular, creating these varying distances.</p><p>Understanding apogee is crucial for space missions – spacecraft use less fuel when launched toward apogee, and satellite operators must account for orbital variations. For amateur astronomers, knowing when the Moon reaches apogee helps predict optimal viewing conditions for observing lunar features and nearby celestial objects.