Hinglish

Night Sky Watching

Class 6 Science · Chapter 12: Beyond Earth · NCERT Curiosity section 12.2

Learn

If you watch the sky for a few hours, the stars seem to move slowly from east to west, just like the Sun does in the day. They are not really moving: Earth is spinning, carrying us around.

One star seems to stay still in the northern sky: the Pole Star (Dhruva tara). It lies almost exactly above Earth's North Pole, so the whole sky seems to turn around it. Facing it means you are facing north!

How to find it: locate Saptarishi. The two stars at the outer end of its bowl are called the pointer stars. Imagine a line through them and extend it about five times their gap: you reach the Pole Star.

For good sky watching, go to a dark place away from city lights, let your eyes get used to the dark for 15 minutes, and use a simple star map. India has a Dark Sky Reserve at Hanle in Ladakh, where the sky is protected from light pollution.

Explore: find the Pole Star.

  1. Draw Saptarishi and then extend the pointer line to the Pole Star (the lone star at the top right).

Remember

  • Stars seem to move from east to west because Earth spins.
  • The Pole Star stays in the north; find it using the pointer stars of Saptarishi.

Quick check

Why does the Pole Star help travellers?

  1. It stays in the north and hardly moves
  2. It is the brightest star
  3. It rises in the west
  4. It is the Moon
Answer

It stays in the north and hardly moves. It sits above the North Pole, so it always shows north.

Think about it

If you stood at the North Pole, where in the sky would the Pole Star be?

One answer

Almost directly overhead. The further north you go, the higher it appears in the sky; near the equator it is close to the horizon.

Practice

Practise with fresh questions at three levels (easy, medium, hard), some answered hands-on, with hints and worked answers. Get 4 of your last 5 right to finish the topic.