What is the prime meridian?

Defining the Prime Meridian. Look at this globe. On most globes, all the way around the sphere, you'll notice there are light lines drawn vertically as well as horizontally. These lines make up the Geographic Grid, a grid system that was created for Earth so that a location on the planet could be more easily described. read more

A prime meridian is a meridian (a line of longitude) in a geographic coordinate system at which longitude is defined to be 0°. Together, a prime meridian and its antimeridian (the 180th meridian in a 360°-system) form a great circle. read more

The Prime Meridian is an imaginary line that, similar to the equator, divides the earth into eastern and western hemispheres. It is sometimes referred to as the Greenwich Meridian. All lines of latitude and longitude are measured in degrees. read more

The prime meridian is the vertical line that marks the 0° longitude measurement on the globe of Earth. The line intersects the latitude lines that are horizontal. Not every globe has the same prime meridian measurement, but most measure it as a line that passes through England, France, Spain, Togo, and down to Antarctica. read more