NCERT Solutions Curiosity Chapter 12 & 23512.1 Stars and Constellations — In-text Questions

Book page 233 Updated on2026-09-05

Q1.
Do we find patterns among the stars just for fun or is there some use of these patterns?
Answer

Both — but the use came first. Star patterns were a serious, practical tool long before they were entertainment.

  • Finding directions. Before the magnetic compass, and long before GPS, sailors and travellers steered by the stars. The Big Dipper leads you to the Pole Star, which stands almost fixed in the north. Caravans crossing Nubra in Ladakh used exactly this trick. It is still kept as a backup method in emergencies.
  • Recognising stars. Thousands of stars look alike. Grouping them into shapes makes it possible to point at one and say which star it is — "the bright one at the bottom-right of Orion".
  • Keeping a calendar. Different constellations rise in different seasons, so their appearance told people when to sow, when to harvest and when a festival was due.
  • Storytelling and culture. Each pattern carried a story, and the story helped children remember the pattern.
Why the Pole Star works as a direction-finder: it lies almost exactly above the Earth's North Pole, along the line of the Earth's axis. As the Earth spins, every other star seems to wheel across the sky, but the Pole Star hardly moves. Face it, and you are facing north.
Did you know? In the early twentieth century the International Astronomical Union (IAU) fixed agreed boundaries and listed 88 constellations, dividing the entire sky into 88 regions. So today a constellation is a region of the sky, not just a pattern of stars.
Q2.
How can we identify some of these constellations in the night sky?
Answer

Learn one landmark pattern first, then hop from it to the others. That is how every sky-watcher begins.

  1. Know the shape before you go out. Study Fig. 12.3 and Fig. 12.4, or print them, so the shape is already in your head.
  2. Know where and when to look. Not every constellation is visible from every place on every night. The Big Dipper is best seen towards the north at about 9 p.m. in summer; Orion is best seen in India from December to April, after sunset.
  3. Start with the easiest. The three evenly spaced stars of Orion's belt and the ladle of the Big Dipper are unmistakable.
  4. Star-hop. Big Dipper → Pole Star (5× the gap between the two pointer stars). Orion's belt → extend the line eastwards → Sirius, the brightest star in the night sky.
  5. Use a sky-map app such as Sky Map or Stellarium on a mobile phone to confirm what you are looking at.
Tip: choose a dark, open place away from street lights and tall buildings, and wait about half an hour for your eyes to adjust to the darkness. Many more stars appear once your eyes are dark-adapted. Never go to a dark open place at night without an adult.
Was this helpful? Report an error