Astronomy Practice Exam

What is a defining feature of circumpolar constellations?

1. They change position seasonally

2. They are always visible in the night sky from certain latitudes

3. They are stable and never change

4. They only appear during specific months

The correct answer is: They are always visible in the night sky from certain latitudes

Circumpolar constellations are defined by their unique visibility in the night sky from certain latitudes, particularly those closer to the poles. These constellations circle around the celestial poles and, due to the Earth's axial tilt and rotation, do not set below the horizon for observers located at higher latitudes. This means that from these locations, these constellations can be seen at any time of the year, making them a consistent and reliable feature of the night sky. Because they remain above the horizon throughout the night and across all seasons, they can be used for navigation and as reference points in the sky. In contrast, constellations that change position seasonally or only appear during specific months are not considered circumpolar. The reference to stability, while it may reflect their consistent presence in the sky, does not encompass the defining nature and consistent visibility that characterizes circumpolar constellations.