Astronomy Practice Exam

How did ancient societies use astronomical observations for navigation?

1. By measuring the brightness of stars

2. By utilizing the phases of the moon

3. By determining the elevation of the North Star

4. By calculating the position of the sun

The correct answer is: By determining the elevation of the North Star

Ancient societies relied heavily on astronomical observations for navigation, and one of the most significant ways they achieved this was by determining the elevation of the North Star, also known as Polaris. This star holds a unique position in the northern hemisphere; it is located nearly directly above the North Pole. Thus, it remains relatively fixed in the sky, allowing navigators to use its position to ascertain their latitude. By measuring the angle of elevation of Polaris above the horizon, sailors and travelers could effectively gauge their north-south position on Earth, which was crucial for traversing vast distances accurately. Using Polaris was particularly beneficial at night when other points of reference could be obscured. In addition, the North Star's visibility and reliance on straightforward angular measurements made it accessible for ancient navigators long before advanced navigational instruments were developed. This method was foundational for navigation and is still used by modern mariners today for basic celestial navigation.