The choices below are for the following questions. For each question, choose the letter for the real motion that is responsible for the apparent motion as seen from Earth.
-In the year A.D. 15,000, Vega will be a better north star than Polaris.
A)Earth rotates once each day.
B)Earth revolves around the Sun once each year.
C)The direction of Earth's axis in space precesses with a period of 26,000 years.
D)Stars appear to move randomly in the local solar neighborhood.
E)The universe is expanding.

Question

Quizplus · Accepted Answer

The apparent motion of the stars in the sky is caused by the rotation of the Earth on its axis. However, due to the precession of Earth's axis in space, the direction of the North Celestial Pole changes over time. Currently, the star Polaris is the closest visible star to the current location of the North Celestial Pole, making it the North Star. However, in the year 15,000 AD, the direction of Earth's axis will have precessed enough to make the star Vega the closest visible star to the North Celestial Pole, making it the new North Star.

The Choices Below Are for the Following Questions