SCALING THE DISTANCE
The Sun, and each of the planets in the model, need to be scaled for size and distance.
We know that the actual diameter of the Sun (1,391,016 kilometres) is represented by the 9,000 millimetres "Big Ball".
Therefore 1 kilometre is represented by 0.00647 millimetres.
The orbit of each planet is a specific distance from the Sun. It is not exactly the same distance away at every point in its orbit, but there are accepted orbit distances that are used here.
Therefore it’s simply a matter of multiplying out the known orbits to determine how far from the "Big Ball" we need to place each of our planets in the model.
The Earth, for example, has an orbit (or distance from the Sun) of 149,570,000 kilometres.
That scales in our model to 968 metres away from the "Big Ball".
If you know the Naas area, that puts the Earth in our model along the road towards Naas, past the Odeon and the entrance to the racecourse, and just in front of the first row of houses in the Gallops estate.
Of course there are infinite other positions we could put the Earth as it could be placed anywhere along its orbit around the Sun.
The orbits of all the other planets can be modelled in the exact same way - all you need to know is the orbit distance.