Prime Meridian on the move

The historical prime meridian runs through a telescope established in 1851 by Sir George Airy at the Royal Observatory at Greenwich, England. It was adopted as an international standard as the prime meridian for zero longitude in 1884 during the International Meridian Conference held in Washington, D.C.

The observatory’s line in the pavement is a major tourist attraction, but the prime meridian used by satellite navigation systems is located 102 meters east of that historic location.