Meridian Longitude _verified_ Jun 2026

is the geographic coordinate that specifies the east-west position of a point on the Earth's surface. It is an angular measurement, expressed in degrees (°), minutes ('), and seconds ("), ranging from 0° at the Prime Meridian to +180° eastward and −180° westward .

Meridian longitude is more than a line on a map—it is the foundation of global navigation, timekeeping, and our shared understanding of location. From ancient astronomers to modern GPS, the quest to measure how far east or west we are has driven innovation and connected the world. The next time you look at a map, remember that every vertical line tells a story of geometry, history, and human ingenuity. meridian longitude