What Columbus used instead of the North Star

Christopher Columbus didn’t navigate by the North Star. At least, not directly. Columbus is a controversial figure from a modern perspective, and he undeniably made many mistakes. But this wasn’t one of them. Mariners sailing for Spain and Portugal in the 1490s just didn’t use the North Star as true north. Because back then, it wasn’t. Polaris, the North Star, is the brightest star in the constellation Ursa Minor, the little bear. It’s also the closest bright star to the North Celestial Pole: the point in the sky right above the North Pole of the Earth. As the Earth spins about its axis, all the stars in the sky appear to rotate around the North Celestial Pole, for an observer in the Northern Hemisphere. The angle between the North Celestial Pole and the horizon is equal to your latitude. Polaris isn’t exactly at the North Celestial pole – it’s about two thirds of a degree away from it. So if you were to treat Polaris as true north for celestial navigation, you could be sailing up to…