☰ خطة العام · العلوم (بالإنجليزية)

Stars, the Moon’s shapes and a planetarium

الأسبوع 27 · المحور الرابع «التغير والثبات»، الوحدة الرابعة «الأنماط في السماء»، المفهوم 4.2 «أنماط الحركة في السماء» (ب): النجوم والنموذج والقبة السماوية · 3 دروس
3

A planetarium of my own

Discovery Education Science P5: Term 2, Unit 4, pp. 157–159
GoalDescribe how a planetarium shows the sky and design and test a simple star projector.
New words
planetarium · a building with a dome where the night sky is shown on the ceilingprojector · a machine that shines pictures or light patterns onto a surfaceengineering design · the steps engineers follow to solve a problem: ask, imagine, plan, build, test and improve
Explanation

A planetarium is a theatre with a round dome for a ceiling. In the dark, a projector fills the dome with stars, planets and constellations, so visitors can see the night sky even in the middle of the day. Computer programs can show the sky as it looked on any night, even long ago, and speed it up so a whole night passes in minutes. A planetarium director is a scientist, often an astronomer, who studies objects in space and manages the building and its shows. You can design a simple star projector yourself with the engineering design steps. Ask: how can I show a constellation on a wall? Imagine ideas. Plan with a drawing. Build a box with a torch inside and small holes in one side, made by a grown-up. Test it in a dim room. Then improve it, for example by making the holes in the pattern of a real constellation.

Worked examples
Distance to the wallPattern
2 mbigger, dimmer
1 msmaller, brighter
Hana’s star projector is a box with a torch inside. A grown-up makes 7 small holes in the shape of Orion. On the wall 2 m away, the pattern is clear. When she moves the box to 1 m from the wall, the pattern is smaller but brighter.
A planetarium show starts at 4:15 and lasts 45 minutes. It ends at 4:15 + 45 minutes = 5:00. A class of 28 children needs 28 tickets, and a ticket is for one seat.
torch insidebox with holesnever look into the light✗
Safety rules for the star projector: a grown-up makes the holes and covers sharp edges with tape, nobody looks into the torch, and the room is dim, not pitch dark, with a grown-up in it.
Class activity

Design a star projector (a grown-up helps). Ask: how can I show a pattern of stars on the ceiling? Draw 2 ideas and choose one. Use a small box or a tube, a torch, black paper and tape. A grown-up makes 6 to 8 small holes in the pattern of a constellation you choose. Test it in a dim room and measure how far away the pattern looks best. Write what worked, what did not and one improvement. Do not look into the torch.

Practice
1
What does a planetarium show, and where does it show it?
2
Put the design steps in order: build, ask, test, plan, improve, imagine.
3
A show starts at 2:30 and lasts 40 minutes. When does it end?
4
Your star projector’s pattern is too dim. Give two ways to improve it.