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NCERT Solutions Curiosity Chapter 12 & 252Projects and further exploration — Learning further

Book page 251 Updated on2026-09-05

Q1.
Try to find out the names of planets in your local language. Also, find out the stories associated with stars and constellations in your region. Present these stories in a pictorial form.
Answer

How to do this project: ask your grandparents, a local priest, a farmer or a fisherman — they usually know the old names and the stories better than any book. Note the name, the language and the story in your notebook, then draw it.

Sample answer — names of the naked-eye planets (the textbook itself gives the Sanskrit-derived set on page 241):

EnglishSanskrit / HindiTamilTeluguMalayalam
MercuryBudhaPuthanBudhuduBudhan
VenusŚhukraVelliShukruduShukran
EarthPṛithvīBhoomiBhoomiBhoomi
MarsMangalaSevvaiKujudu / AngarakuduChovva
JupiterBṛihaspati / GuruGuruGuruvuVyazham
SaturnŚhaniSaniShaniShani

Sample answer — stories from the chapter and around India:

  • Central India (tribal communities): the four stars of the Big Dipper that make a rough rectangle are grandmother's cot, and the other three stars are three thieves stealing it away.
  • Konkan coast (fishermen): the same four stars are a boat, and the last three stars are the neck of the boat.
  • Across India: the seven stars are the Saptaṛiṣhi, the seven sages, and the Pole Star is Dhruva, the boy whose steadfastness earned him a fixed place in the sky.
  • Comets are called Dhūmaketu in Sanskrit, Pucchya-Taro (star with a tail) and Zendya-Taro (star like a flag) by different tribes of India.
How to present it pictorially: take a black chart paper. Stick small silver or white star stickers in the correct pattern. Over them, draw the imagined shape in thin white chalk or a gel pen — the cot, the boat, the sages. Write the story in two or three lines below each panel. Give your poster a title and display it in class.
Q2.
If there is a planetarium or a science museum nearby, then you can visit it, especially if a night sky observation session is scheduled by them. You will get to see the Moon, the planets and the stars through a telescope. If you visit the planetarium during daytime, you can also see their models, pictures and sky shows.
Answer

How to plan the visit:

  1. Look up the planetarium or science museum nearest to you and check its show timings and whether it holds night sky observation sessions. Museums, planetariums, Higher Education Institutions and Amateur Astronomy Clubs all organise them.
  2. Go with your teacher, parents or an adult. Carry a notebook and pencil.
  3. Before you go, list three questions you want answered — for example, "How big is the telescope?", "Which planet is visible tonight?", "Why is Saturn's ring flat?"

What you will actually see:

ObjectWhat a small telescope shows
MoonCraters, mountains and the sharp line between the lit and unlit halves
JupiterA small striped disc with up to four tiny moons in a line beside it
SaturnThe rings — the sight most visitors remember for life
VenusA brilliant crescent, like a miniature Moon
Star clustersKṛittikā (Pleiades) resolves into dozens of separate blue stars
Tip: in a daytime visit do not skip the sky show under the dome. It can compress a whole night's rotation into a few minutes, so you can actually watch the Saptaṛiṣhi swing around the Pole Star — the very thing Question 10 asks you to observe over several hours.
Q3.
Find out if the increasing light pollution is causing problems for humans, wildlife and the environment. Write an action that you would take at the personal level to control light pollution.
Answer

Yes — light pollution causes real harm, and it is growing sharply all over the world. The excessive artificial light we throw into the night sky affects three groups.

AffectedProblem caused
HumansBright light at night disturbs sleep and the body's day–night rhythm; glare from badly aimed lamps dazzles drivers; energy — and money — is wasted lighting up the sky instead of the ground.
WildlifeInsects swarm around lamps all night and die, and fewer insects means less food for birds and less pollination. Migrating birds get confused by lit-up buildings. Newly hatched sea turtles on our coasts crawl towards bright hotel lights instead of the sea. Bats, owls and other night animals lose their hunting grounds.
Environment and scienceThe night sky is lost to most city children. Astronomers cannot study faint objects, which is why dark sky reserves and parks — like the Hanle Dark Sky Reserve in Ladakh, notified in December 2022 — are now being created and protected.

Sample answer — what I will do at my personal level:

  • Switch off the outdoor bulb of our house and the terrace light when nobody is using them, and ask my family to do the same.
  • Ask my father to fit a simple shade or hood over our gate lamp so the light falls downwards on the path and not sideways into the sky and the neighbour's window.
  • Use a lower-power, warm-coloured bulb outside instead of a glaring white one.
  • Draw the curtains at night so indoor light does not spill outside.
  • Make a poster for my school notice board — "Light the ground, not the sky" — and explain to my class what light pollution costs us.
Why this small action matters: unlike most pollution, light pollution disappears the instant the cause is removed. Switch a badly aimed lamp off and the sky above it is clean again that same night. Very few environmental problems can be repaired that quickly.
Q4.
Find out the weather conditions due to which the Indian Institute of Astrophysics (IIA) found Hanle, Ladakh a suitable place to set up an observatory.
Answer

The Indian Astronomical Observatory at Hanle stands on the highest peak of the Digpa-ratsa-Ri range — now renamed Mount Saraswati — at a height of about 4,500 m. It is one of the highest observatory sites in the world. IIA chose it because almost every condition an astronomer needs comes together there.

Condition at HanleWhy it helps a telescope
Very few clouds — a large number of clear nights every yearMore nights available for observation; a cloudy site wastes an expensive telescope
Extremely dry, cold-desert air with very little water vapourWater vapour absorbs infrared light; dry air lets much more of it reach the telescope
Very high altitude — much of the atmosphere is already below youLess air to look through means sharper, steadier images
Calm, steady air with little turbulenceStar images stay crisp instead of shimmering and blurring
Remote and thinly populated — almost no light pollutionVery faint objects can be recorded; this is why the area was declared the Hanle Dark Sky Reserve in December 2022
Very little dust and industrial hazeCleaner air scatters less light and keeps the sky background dark
Did you know? One of the telescopes at Hanle is the Himalayan Chandra Telescope, named after the Nobel Prize winning scientist Subrahmanyan Chandrasekhar. The reserve is open to the public all year, and local people have been given small telescopes and trained by IIA as Astronomy Ambassadors — a fine example of astro-tourism helping a whole region.
Q5.
If you enjoy doing embroidery, try to embroider on a dark coloured cloth the constellations that you have seen (Fig. 12.15). Otherwise, you may use your creativity and depict constellations in multiple other ways using various art and craft ideas.
Answer

How to make the embroidered star chart:

  1. Take a piece of dark blue or black cloth and stretch it in an embroidery hoop.
  2. Copy the constellation from Fig. 12.3 or Fig. 12.4 on to tracing paper. Mark each star with a dot, making the dot bigger for a brighter star.
  3. Transfer the dots to the cloth with a fine tailor's chalk.
  4. Work each star as a French knot or a small cluster of straight stitches in white, silver or pale yellow thread. Use a bead or a sequin for the brightest star — Sirius, or Betelgeuse in red.
  5. If you wish, join the stars with a very fine running stitch in grey thread to show the imagined pattern, and embroider the name below in back stitch.

Other ways to depict a constellation — pick any one:

  • Pin-prick lantern: prick the star pattern into black chart paper with a needle, roll it into a cylinder and stand a torch inside. The pattern appears on the ceiling of a dark room.
  • Thread-and-nail art: hammer small nails into a painted wooden board at the star positions and stretch white thread between them.
  • Rangoli / clay diyas: lay out the Saptaṛiṣhi on the floor with white rangoli powder, or place tiny diyas at the seven star positions on Diwali.
  • Bottle-cap mosaic or glow paint: glue silver bottle caps, or dab glow-in-the-dark paint, on a black sheet.
  • Class night-sky mural: each student embroiders or paints one constellation on a square, and all the squares are stitched together into a single sky quilt for the classroom wall.
Tip: keep the relative distances and the relative brightness of the stars roughly correct. A star chart is useful only if someone can hold it up against the real sky and recognise the pattern.
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