Understanding the Prime Meridian
The Prime Meridian is the planet's zero degrees longitude line, serving as a reference for timekeeping and navigation. It runs from the North Pole to the South Pole and is essential for global geographical coordination.

Location and Significance
- The Prime Meridian is located at 0° longitude.
- It passes through Greenwich, a district in London, UK, which is why it is often referred to as the Greenwich Meridian.
- It divides the Earth into the Eastern and Western Hemispheres.

Role in Time Zones
- The Prime Meridian is the basis for Coordinated Universal Time (UTC), which is used worldwide.
- Each hour of time corresponds to a 15-degree shift in longitude, leading to the establishment of different time zones.

Geographical Reference
- It serves as a reference point for various geographical measurements and mapping.
- All longitudes are measured in degrees east or west from the Prime Meridian, up to 180°.

Historical Context
- The adoption of the Prime Meridian was established at the International Meridian Conference in 1884.
- Prior to this, multiple meridians were in use, causing confusion in navigation and timekeeping.

Impact on Navigation
- It plays a crucial role in maritime and aerial navigation.
- Accurate positioning using the Prime Meridian allows for safe and efficient travel across the globe.
In summary, the Prime Meridian, defined at 0° longitude, is fundamental for navigation, global timekeeping, and serves as a primary reference for geographical measurements.