journey into space

bringing the earth down to size


For the teacher: CAN THE SPACE SHUTTLE FLY TO THE MOON?

Many students have the impression that the space shuttle is way out in space. They get this impression from the free falling antics that they see the astronauts performing on the shuttle. Many students think that gravity "turns off" as soon as you get into space.

These and other misconceptions are common, but can be addressed by a number of simple activities. A very well received activity that has been the subject of a number of my workshops is "Bringing the Earth Down to Size".

BRINGING THE EARTH DOWN TO SIZE

AIM: To compare large heights from the surface of the Earth with its diameter.

KEY CONCEPTS:

     Few structures, natural or made by humans, provide much contrast in height to a scaled model of the Earth

     Drawing things to scale helps to develop accurate mental pictures.

MATERIALS:

           A3 (or larger) paper    Pencil Cotton (1.1 metres per group)    Metre rule

           Centimetre ruler Masking Tape     Earth Globe   Calculator (OPTIONAL)

PROCEDURE:

1. Tape the paper to the desk so it will not shift later

2. Measure just over 1 metre of cotton and tie one end to the pencil

3. Tape the other end to the desk as shown in the diagram, so that you can swing an ARC of exactly 1metre about half way up the sheet of paper. This 1metre will represent the RADIUS of our Earth.

HINT: You can wrap the string around the pencil a few times to get it more exactly equal to 1 m.

4. The ARC that you have drawn could be continued in a complete CIRCLE to represent the outside surface of our EARTH. If we completed the circle we would have drawn a scale modelof the Earth that was 1metre in RADIUS.

5. Now use the values on the SCALE HEIGHT TABLE that follows to carefully measure out the distances above and below the surface of the Earth of the features mentioned. CLEARLY LABEL EACH ITEM or draw a picture if you wish, and THEN ANSWER THE QUESTIONS ASKED.


ASK YOUR TEACHER IF YOU NEED HELP WITH ANY OF THIS

ANSWER SHEET                                         NAME:………………………..…

ITEM

REAL HEIGHT

SCALE HEIGHT

Earth's radius

6,380 km

1.0   m (the outer surface)

Average altitude of the Space Shuttle

300 km

47.02 mm above surface

Altitude of a cruising international jumbo jet

12.2 km

1.91 mm above surface

The outer limit of Earth's atmosphere

150 km

23.51 mm above surface

Deepest Ocean Trench

11.0 km

1.72 mm BELOW surface

Mount Everest

8.8 km

1.38 mm above surface

A 100 story high skyscraper

0.3 km

0.05 mm above surface

TEACHER MARK FOR GROUP'S PRACTICAL EFFORTS                                   …………….. (5)

Answer these questions in space provided (marks in brackets)

1. What is the DIAMETER of the Earth in the model that you drew?                              (1)

2. If you could run your hand over a model of the Earth of the size you drew (radius 1m),
how would it
feel? EXPLAIN your answer.                                                 (3)

3. Show your teacher on the Globe of the Earth that is provided, the approximate height of the orbiting

Space Shuttle.

Teacher Check:

Very good (4 marks)

Good (3 marks)

Not quite right (2 marks)

No where near (0 marks)

4. If the Earth's diameter is approximately 12,800 km and the Moon's is 3,200 km what size radius

would the Moon be compared to our 1m radius Earth?                                         (1)

5. If the distance from the Earth to the Moon is approximately 400,000 km, how far away would the
MOON be from your 1m radius scale model of the Earth?                                      (1)

Download RTF file