Identifying star patterns

One of the items in the educational trip
organised for the students of grade 9 in Saman Vidyalaya was a visit to the planetarium.All students entered the hall of the planetarium and took their seats. They were observing the roof of the planetarium. It was a white hemisphere.
The hall became gradually dark accompanied by lovely music. The
‘Planetarium sky’ got lit up by stars one by one, till the white area was completly filled with stars. The lecturer of the planetarium started his lecture. “We
welcome all of you to our planetarium today. First of all, let us identify the 4 directions of our planetarium sky.”
Having said this, he directed the special torch he held in his hand up to the planetarium sky. A small arrow appeared in the sky. He directed the torch to the letters N, S, E, W
and drew the attention of the audience to them. Students observed that all the stars appearing were moving from the east to the west direction. The lecturer explained that the stars in the night sky showed as if they
appeared to move from the east to the west because the earth is rotating from the west to the east. This is similar to what we observe when we are travelling in a vehicle, the trees and houses on either sides of the road appear to move backwards.

Do yo know ?

In a planetarium, it is possible to view the sky on any

day, at any time and at any place. This is done by an

instrument called the Universal Projector. This

instrument is mounted on a stage at the centre of the planetarium. From here it is possible to observe the

eclipses of the sun and the moon, meteorite rains, comets as well as the view of the solor system to a person observing it from outside, and the view observed if one were to travel in a space craft in a journey through the solar system.To observe these views get into the web www.starrynight.com. You can obtain compact disc containing all these information from the Arthur C.Clerk Centre.

To study about the star patterns, observing the night sky is a ‘must’. The instructions you have to follow are given below.
• Select a day close to new moon (Amawaka) day.
• Cover the face of your torch with a red 
   coloured cellophane paper.
• Stand on a stage during observations in order to protect yourself from snakes,
   poisonous animals and thorny bushes.
• Be prepared for sudden changes of weather.
• Get a photocopy of the star maps provided in this book and use them.
• Keep a note book and a pencil.
• It is better if you use a compass to identify directions. If not, use the direction of the buildings 
  and trees you noted during the day. Once the star patterns are
identified they will help you to identify directions.The imaginery pictures built up by joining the stars observed in the night sky are known as constellations. These pictures may be of natural objects or characters from
mythology. under image shows some constellations that can be seen in the sky in the months of February and March around 8 p.m. in the night.