What is the Prime Meridian and why is it in Greenwich? | Royal Museums GreenwichWhy was Greenwich chosen as the home of the Prime Meridian and Greenwich Mean Time, and what do those terms mean?The Royal Observatory in Greenwich is where east meets west at Longitude 0°. What is a meridian? A meridian is a north-south line, selected as the zero reference line for astronomical observations. By comparing thousands of observations taken from the https://www.rmg.co.uk/explore/astronomy-and-time/astronomy-facts/history/the-prime-meridian-at-greenwich