Universal Time (UT), adopted in 1928 by the International Astronomical Union, is the time standard used in astronomical almanacs, referencing the 0° longitude meridian (Greenwich). For high precision, ...

The Prime Meridian is the imaginary line running between the North and South Poles that's used to indicate 0° longitude. It passes through Greenwich in southeast London, and is therefore sometimes ...

If you use your smartphone’s GPS to find Earth’s prime meridian – the north-south line marking zero degrees longitude – at Greenwich Observatory, you’ll notice something a bit odd. You won’t be ...

In 1884, a delegation of international representatives convened in Washington, D.C. to recommend that Earth's prime meridian (the north-south line marking zero degrees longitude) should pass through ...

The prime meridian has shifted a few hundred feet. An astronomer helped figure out why. In 1884, a delegation of international representatives convened in Washington, D.C. to recommend that Earth's ...