Expert: Jayendra Upadhye - 6/3/2008

Question
Hello,
I have a question on pole star.Please can you answer that why is the pole star important?
Thank You!

Answer
Hi Firdaus,
Why are you asking such a simple question?
1 - It is important because one can know ones position on the globe by looking up its "altitude" in degrees above the horison, when looking along true north direction. The degrees above horizon tell you how many degrees "away" you are from the pole.
at the tropic of cancer, its ghieght would be 23.5 degrees above horizon. giving your latitude = 23.5 degrees North of the equator.
At the poles, it would be directly overhead, giving your location as 90 deg north latitude.

The longitude you would have to calculate using a sextant, an instrument used by sailors. You would also need an accurate clock with you, set to show GMT (Greenwhich Time).

Other than that it has little practical significance. The earth's axis points towards it but not accurately.
In fact it wanders and points to different stars over a period of approx 25000 years. when it completes a circle and again points towards the current pole star we call Polaris.

This phenomenon is caleld "precession of the equinoxes".
look it up on wikipedia.

regards.
Jayen