In the absence of a star like Polaris that indicates a celestial pole, ancient navigators used other stars and constellations to determine cardinal directions and their ship’s course. They realised that the positions where they appear and disappear at the horizon (the bearings) do not change during a lifetime.
You could be thinking “How do sailors use constellations to navigate?”
The stars are fixed in the sky unlike the planets—a word that actually means “wanderer ”. At the same time of day and on the same date each year, a star will be exactly in the position in the sky that it was the year before and will be next year.
The stars allowed farmers to plan ahead and form agriculture, and constellations made it easier to recognize and interpret the patterns in the sky. The constellations also helped with navigation. It is fairly easy to spot Polaris (The North Star) once you’ve found Ursa Minor (Little Dipper constellation).
Is it easier to navigate using stars or a compass?
In fact finding direction using the stars is much quicker and easier than using a compass. It is also a lot more fun. To navigate using the stars all we need do is find a star that is directly above the place we want to get to and it will point exactly the right direction for us, from quarter of the globe away.
To navigate using the stars all we need do is find a star that is directly above the place we want to get to and it will point exactly the right direction for us, from quarter of the globe away.
Hundreds of years ago, people made tools to navigate with that could measure angles between the stars and the horizon —this way they could do some calculations and figure out their latitude.
Why do astronomers ask for coordinates when showing stars to people?
And usually they will want to tell someone which stars or objects they may be looking at. If they just give the coordinates (numbers) the other person is not likely to have an immediate idea of where the star is located in the sky.