Year 7 Science · Unit 4 · Lesson 10
Foundation Worksheet
Learning Goals
Fill the gap
Choose the correct word from the word bank. Each word is used at most once. Two words are not needed: cross them out.
The Moon does not make its own light. We see it because it sunlight. The Sun always lights up exactly of the Moon, the side facing the Sun. When the lit part we see is growing towards full moon, the Moon is . When the lit part is shrinking back towards new moon, the Moon is . The whole cycle of phases takes about , then it repeats.
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. The Moon’s phases are caused by Earth’s shadow falling on part of the Moon.
Correct it:
2. Earth’s shadow darkening the Moon is only ever seen when the Moon is full.
Correct it:
3. During a lunar eclipse, the Moon often turns a dim red colour.
Correct it:
4. At full moon, the Moon is between the Sun and the Earth.
Correct it:
5. During a solar eclipse, the Moon’s shadow falls on part of the Earth.
Correct it:
6. Ordinary sunglasses make it safe to look at the Sun during a solar eclipse.
Correct it:
Order the eight phases
Start at new moon. Number the phases from 1 (new moon) to 8, in the order they happen over one cycle.
| Number | Phase |
|---|---|
| First quarter | |
| Last quarter | |
| New moon | |
| Full moon | |
| Waning crescent | |
| Waxing crescent | |
| Waning gibbous | |
| Waxing gibbous |
Scenario: Mia’s lamp-and-ball model
Scenario
In a darkened room, Mia uses a bright lamp, a basketball and a tennis ball on a stick. She puts the basketball between the lamp and the tennis ball, all in a straight line. The tennis ball goes dark.
1. (a) Say what the lamp, the basketball and the tennis ball each stand for. (b) Name the event Mia has modelled, and the only Moon phase at which it can happen.
Read the data: Sam’s Moon diary
Scenario
Sam checked the Moon every few days in March and wrote down what it looked like.
| Date | What Sam saw | Phase |
|---|---|---|
| 1 March | Almost nothing | New moon |
| 5 March | A thin sliver, bigger each night | |
| 8 March | Exactly half of the lit side | First quarter |
| 12 March | More than half lit, still growing | |
| 16 March | A full bright circle | Full moon |
| 20 March | More than half lit, now shrinking | |
| 23 March | Half lit again, the other half from before |
Source: made-up sample diary.
2. Write the four missing phase names in the last column of Table 1.
3. (a) How many days did the Moon take to go from new moon to full moon? (b) The whole cycle of phases takes about 29.5 days. Predict the date of the next new moon after 1 March. Show your working.
Next new moon: March
4. Extended response. Your cousin says: “The Moon changes shape because Earth’s shadow covers part of it. And if the Moon goes round us every month, there should be an eclipse every month.” Write a reply that corrects both ideas.
Fill the gap
reflects; half; waxing; waning; 29.5 days (1 each). Not used: Earth’s shadow, 7 days. [5 marks]
True or false
1. False: the changing positions of the Sun, Earth and Moon change how much of the lit half we see. 2. True. 3. True. 4. False: at full moon the Moon is on the far side of Earth from the Sun (between them at new moon). 5. True. 6. False: never look straight at the Sun; use certified eclipse glasses or a pinhole projector. (1 each) [6 marks]
Order the eight phases
Reading down the table as printed, the correct step numbers are 3, 7, 1, 5, 8, 2, 6, 4. In order: New moon; Waxing crescent; First quarter; Waxing gibbous; Full moon; Waning gibbous; Last quarter; Waning crescent. All 8 correct = 3; 6 or 7 = 2; 4 or 5 = 1. [3 marks]
Scenario: Mia’s lamp-and-ball model
1. (a) Lamp = Sun, basketball = Earth, tennis ball = Moon (1). (b) Lunar eclipse (1); only at full moon (1). [3 marks]
Read the data: Sam’s Moon diary
2. 5 March waxing crescent; 12 March waxing gibbous; 20 March waning gibbous; 23 March last quarter. All four = 2; two or three = 1. [2 marks]
3. (a) 16 − 1 = 15 days (accept about 15) (1). (b) 1 March + 29.5 days (1) = 30 or 31 March (accept either) (1). [3 marks]
Question 4
Marking guide: 1 the Moon reflects sunlight and makes no light of its own; 1 the Sun always lights half of the Moon; 1 the phases are how much of that lit half we see as the positions of the Sun, Earth and Moon change, not Earth’s shadow; 1 Earth’s shadow falls on the Moon only in a lunar eclipse, at full moon; 1 the Moon’s orbit is tilted about 5° to Earth’s path around the Sun; 1 so most months the Moon passes a little above or below the line: no eclipse. [6 marks]
Model answer: The Moon reflects sunlight, and the Sun always lights half of it. As it orbits Earth, the positions of the Sun, Earth and Moon change, so we see more or less of the lit half. Earth’s shadow falls on the Moon only in a lunar eclipse, at full moon. There is not an eclipse every month because the Moon’s orbit is tilted about 5°, so it usually passes just above or below the line.
Common error: blaming the phases on Earth’s shadow.