Meridian Coordinates Better Jun 2026

Example: If your local sidereal time = object's RA → object is on the meridian.

Unlike latitude (which has a natural zero at the Equator), longitude has no natural starting point. For centuries, sailors could measure latitude using the sun and stars, but they remained "lost at sea" regarding longitude. Determining a ship’s meridian coordinate required knowing the exact time both at the ship’s location and at a reference point (like Greenwich). The invention of the marine chronometer by John Harrison in the 18th century solved this problem, revolutionizing global navigation. meridian coordinates