Year 7 Science · Unit 4 · Lesson 17
Extension · Foundation Worksheet
Learning Goals
Extension · optional
Asteroids, comets, meteors and the moons of other planets are not in Science 7–10 at all, so nothing on this sheet is assessed in Year 7. Our own Moon is: its phases and eclipses are covered in the core lessons of this unit.
Match each term to its meaning
Write the letter of the correct meaning next to each term. Each letter is used once.
| Term | Letter | Meaning |
|---|---|---|
| Moon | A. A rocky leftover from when the Solar System formed | |
| Asteroid | B. A piece of space rock that survives the fall and lands on the ground | |
| Comet | C. A bowl-shaped hollow blasted out when a large meteorite hits the ground | |
| Meteor | D. A natural satellite that orbits a planet | |
| Meteorite | E. The bright streak of light people call a “shooting star” | |
| Crater | F. An icy “dirty snowball” that grows a glowing tail near the Sun |
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.
Asteroids are rocky from when the Solar System formed. Most of them are found in the asteroid belt, which lies between the orbits of and . Even though there are millions of them, the belt is mostly .
Sort it: moon, asteroid or comet?
Write each item in the correct box. The boxes do not hold the same number of items.
Moon
Asteroid
Comet
1. Leo says: “Every planet has at least one moon.” Explain why Leo is wrong, and name one planet that has many moons.
Read the data: a meteor watch
Scenario: counting shooting stars
On a clear, dark night a Year 7 class lies on the school oval and counts every “shooting star” they see.
| Time | Number counted |
|---|---|
| 8 pm to 9 pm | 4 |
| 9 pm to 10 pm | 7 |
| 10 pm to 11 pm | 9 |
| 11 pm to midnight | 12 |
Source: made-up sample class results.
2. (a) How many shooting stars did the class count altogether? (b) Describe the trend in Table 1.
3. The next morning the class searched the whole oval and found no meteorites. Use the difference between a meteor and a meteorite to explain why.
4. Write a short guide for a family night-sky walk about the smaller members of the Solar System.
Match each term to its meaning
Moon → D; Asteroid → A; Comet → F; Meteor → E; Meteorite → B; Crater → C.
Fill the gap
leftovers; Mars; Jupiter (Mars and Jupiter in either order); empty space. Not used: crowded, Earth. Four correct = 2; two or three = 1. [2 marks]
Sort it: moon, asteroid or comet?
Moon (4): Titan, Phobos, Ganymede, Io. Asteroid (2): lump of rock and metal that never joined a planet; Itokawa. Comet (3): grows a glowing tail; Halley’s; frozen mix of ice, frozen gases, dust and rock. All nine = 3; seven or eight = 2; four to six = 1. [3 marks]
Question 1
Mercury and Venus have no moons at all (1). Jupiter or Saturn has many moons (1). [2 marks]
Read the data: Question 2
(a) 4 + 7 + 9 + 12 = 32 (1). (b) The count went up every hour, from 4 to 12 (1). [2 marks]
Question 3
A meteor is only the streak of light made as a small piece burns up in the air (1). Usually the piece burns up completely; only a piece big enough to survive and land is a meteorite (1). [2 marks]
Question 4
Marking guide: 1 a moon is a natural satellite that orbits a planet; 1 Jupiter or Saturn has many moons; 1 most asteroids are in the belt between Mars and Jupiter; 1 a meteor is the streak of light, a meteorite is the piece that lands; 1 Wolfe Creek Crater (Kandimalal) in the Tanami Desert, WA, was blasted out when a large iron meteorite struck the ground. [5 marks]
Model answer: A moon is a natural satellite that orbits a planet; Jupiter has dozens. Most asteroids, rocky leftovers, sit in the belt between Mars and Jupiter. A “shooting star” is a meteor, the streak of light as a piece of space rock burns up. A piece that lands is a meteorite. A large one can blast out a crater, like Wolfe Creek Crater (Kandimalal) in the Tanami Desert, made by a large iron meteorite.
Common error: swapping meteor and meteorite.