Practical exercise: Making models of the objects of the Solar System

Aids:

• 10 table tennis balls (to make models of the Sun, 8 planets, the Moon), plastic foil (me-dium strong), markers, a drill with a borer for wood with a diameter 2.5 – 3 mm, approx. 10 skewers (ideally with a spike), melting gun, knife, flower arranging material, pro-tractor, flexible formable wire approx. 20 cm long, charts with planet characteristics (on the Internet or hard copies)

Instructions:

1. First we make a model of the Sun. We drill two holes in the opposite sides of a table tennis ball in such way that we can pass a skewer through them. Before we insert the skewer into the ball, we color it in yellow or orange; for inspiration we can use a picture from the Internet or an encyclopedia. We can also use a colored ball.

Then we pass the skewer through both holes in such a way that we have the end of the skewer without the spike about 2 cm above the ‘surface of the Sun’. We then fix the skewer in the ball with the melting gun. From the material for arranging flowers we cut a prism with a base of about 5 x 5 cm and insert there the skewer with the spiked end.

2. Now we make a model of Earth. The method is similar to that of making the model of the Sun. Again, we first drill two holes in the opposite sides of a table tennis ball in such a way that we can pass a skewer through them. Before inserting the skewer, we color the ball according to a picture from the Internet or from an encyclopedia. During the process we pay attention to coloring the ‘Earth’ ball in such a way that the North and South Poles are in the spots where the two drilled holes are.

Then we pass the skewer through both holes in such a way that we have the end of the skewer without the spike about 2 cm above the ‘surface of the Earth’. We then fix the skewer in the ball with the melting gun. From the material for arranging flowers we cut a prism with a base of about 5 x 5 cm and insert the skewer with the spiked end in such an angle that the tilt of the skewer (representing Earth‘s axis) is 23.5 degrees to the vertical.

3. Now we make models of the Moon, Mercury, Venus and Mars. We use the same procedure as for making the model of Earth.

4. We make a model of Saturn. Now we start preparing the model of Saturn’s rings. we cut out a circle with a diameter 4.7 cm from a larger solid plastic board and inside of the circle we cut out a central circular opening with a radius 2 cm. In the cutout circle we draw rings according to pictures from the Internet or an encyclopedia. We must bear in mind that the rings only start in a certain distance from the surface of Saturn (in the model it is around 0.25 cm from the inside edge of the board).

After we have prepared the model of the rings, we make a model of the planet Saturn with its equatorial bands in a similar way as we have made the model planets. Before we place the model of Saturn with a skewer in the base made form the arranging material, we put the rings on the model of Saturn it its equatorial area. We fix their location with the melting gun. Finally, we put the model of Saturn in the base from the flower arranging material the usual way.

5. The same way as we have made the model of Saturn, we will make the models of other gas giant planets, e. i. Jupiter and Neptune (the model of Uranus will be more complicated to make, thus it will be described in a separate section). Rings of these planets will be less distinct and we will find their characteristics on the Internet or in the charts.

6. As the last one, we will create the model of Uranus. The procedure is the same as in the case of other giant planets, only the method how to fix the planet to a base from the flower arranging material is different. Since the inclination of the Uranus’ rotation axis against the vertical to the plane of the ecliptic is 98 degrees, the rotation axis lies virtually in the plane of the ecliptic. To place the model of Uranus in the base, we need to prepare a “bed” from flexible wire. The bed consists of two bars on which there is, in suitable height, an eye into which a skewer is placed. In order to fix the wire better into the base, it is recommended to wind the wire around the skewer which will be pinned into the base.

7. For clarity, it is recommended to fix papers with the names of the objects to the pedestals of the Solar System’s model objects.