NCERT Solutions Curiosity Chapter 12 .2 Night Sky Watching — Activity 12.2: Let us try to locate
Book page 23812 Updated on2026-09-05
Q1.
Look for the Big Dipper during summer time in the early part of the night, say, around 9 p.m. View the sky towards the northern part of the sky and identify the Big Dipper.
Answer
Observation: facing north at about 9 p.m. on a clear summer night, seven fairly bright stars stand out high in the sky in the shape of a ladle (karchhi) — four stars making the cup and three making a slightly curved handle.
This is the Big Dipper, known in India as Saptaṛiṣhi (the seven sages).
It lies inside the constellation Ursa Major.
The middle star of the handle has a faint companion right next to it — if you can split the pair with the naked eye, your eyesight and your sky are both good.
Tip: pick a night when the Moon is not in the sky. Moonlight washes out the fainter stars, and you will need faint stars for the next step.
Q2.
Once you identify the Big Dipper, try to locate the Pole Star. Look at the two stars present at the end of the Big Dipper's cup and imagine a straight line passing through these towards the north. At about five times the distance between these two stars, the imaginary line will lead to another star which is not very bright. This star is the Pole Star.
Answer
Method — the "pointer star" trick:
Find the two stars at the outer end of the cup of the Big Dipper (the edge away from the handle). These are the pointer stars.
Measure the gap between them with your eye. Now draw an imaginary straight line through them, running away from the cup, towards the north.
Travel along that line for about five times that gap.
You arrive at a lone, not very bright star with hardly any stars near it. That is the Pole Star (Polaris, Hindi Dhruva tārā).
Confirm it: the Pole Star is the last star of the handle of the Little Dipper (constellation Ursa Minor).
Star-hopping from the Saptaṛiṣhi to the Pole Star. The two stars at the open end of the cup point the way; go about five times their separation. The lines are imaginary and are not seen in the sky.
Why the Pole Star does not move: the Earth spins about an axis, and the Pole Star lies almost exactly along that axis, above the North Pole. A point on the axis does not swing around as the Earth turns, so this one star stays put while all the others appear to circle around it.
Check it yourself: take a magnetic compass with you. Once you have found the Pole Star, check the compass — the star and the compass needle should both point north.