UPSC Prelims 2012 Q85: Geography – Astronomy & Earth - Sun System
A person stood alone in a desert on a dark night and wanted to reach his village which was
situated 5 km east of the point where he was standing. He had no instruments to find the
direction but he located the pole star. The most convenient way now to reach his village is to
walk in the
- (a) direction facing the pole star
- (b) direction opposite to the pole star
- (c) direction keeping the pole star to his left
- (d) direction keeping the pole star to his right
Answer: (c) direction keeping the pole star to his left
Explanation
Finding east with the pole star
The pole star (Polaris) always lies due north.
If you face north, east is to your right and west to your left.
Now turn to face east: the north, and so the pole star, is on your left.
| Option | Direction of walking | Verdict |
|---|---|---|
| (a) direction facing the pole star | North | Incorrect |
| (b) direction opposite to the pole star | South | Incorrect |
| (c) direction keeping the pole star to his left | East | Correct |
| (d) direction keeping the pole star to his right | West | Incorrect |
About the pole star:
| Point | Detail |
|---|---|
| Why it stays fixed | It lies almost on the line of the Earth's axis |
| Constellation | Ursa Minor; found using the pointer stars of Ursa Major (Saptarishi) |
| Where visible | Only in the Northern Hemisphere |
| Its height in the sky | Equals the observer's latitude |
Answer: (c) direction keeping the pole star to his left.
Why each option is right or wrong
- (a) Incorrect. Facing the pole star means walking north, not east.
- (b) Incorrect. Walking opposite to the pole star takes him south.
- (c) CORRECT. With the pole star on his left, he is walking east.
- (d) Incorrect. Keeping the pole star to his right takes him west.
Key point
Pole star = north. Facing east, north is on the left. Its altitude equals the latitude; located with the pointers of Ursa Major; seen only from the Northern Hemisphere.
Remember
Walking east: pole star on the left.
Common mistakes
- Confusing 'east is to the right when facing north' with 'keep the star to the right'.
- Forgetting that the walker must face east, not north.
- Thinking the pole star moves across the sky like other stars.
Exam tip
Draw a small compass. Put the star at the top (north), then face right (east): the star is on your left.
Sources
- NCERT Class VI — The Earth: Our Habitat, Ch 1 (The Earth in the Solar System)
- NCERT Class VIII — Science, Ch on Stars and the Solar System