## Solar System

If the dimension of the sun were to be scaled down (reduced to) a sphere of diameter 1.4 metre, the planets of our solar system would, then, be reduced to the sizes shown here. The actual diameter of the sun’s disc is about one million kilometer.

The planetary distances, however, are not to scale in this exhibit. Numbers have been appropriately rounded off to present a feel for the magnitude

 Mercury Actual diameter Scaled Diameter On this scale it should have been placed 58m from the sun 4800 Km 0.5 cm Venus Actual diameter Scaled Diameter On this scale it should have been placed 108m from the sun 12000 Km1.2 cm Earth Actual diameter Scaled Diameter On this scale it should have been placed 150m from the sun 12800 Km1.28 cm Mars Actual diameter Scaled Diameter On this scale it should have been placed 225m from the sun 6800 Km0.7 cm Jupiter Actual diameter Scaled Diameter On this scale it should have been placed 780m from the sun 1,43,000 Km 14.3 cm Saturn Actual diameter Scaled Diameter On this scale it should have been placed 1.5 Km from the sun 1,20,500 Km12 cm Uranus Actual diameter Scaled Diameter On this scale it should have been placed 2.9 Km from the sun 51000 Km5 cm Neptune Actual diameter Scaled Diameter On this scale it should have been placed 4.5 Km from the sun 50,500 Km5 cm

### Scale Model of the Solar System

The sizes and the distances in the solar system are so large that it is very difficult for one to visualize. Our daily experiences do not prepare us to think about such large distances.

For example, the distance between Earth and Sun is 150 million Km and the diameter of the Sun is 1.4 million Km. Both of these are so much larger than anything we ever see. Hence it becomes very difficult to imagine these distances and sizes.

One way of getting a feel for these large distances and sizes is to reduce them all by the same amount. That is, divide all these values by a particular number (which is called the scaling factor) so that the distances and the sizes will all be scaled down. And now it becomes much easier for us to compare their sizes and the distances between them.

In this scale model, a dimension of 1million Km is shrunk to 1m.

With this scaling, the diameter of Mercury turns out to be 0.5cm and has to be placed 58m away from the Sun( whose diameter on this scale is 1.4m).

Venus and Earth will have a diameter 1.2cm. One should be placed 108m away from Sun and the other should be 150m away respectively.

Next comes Mars with 0.7cm diameter that has to be placed 228m away.

Jupiter with a diameter of 14.3cm should be placed 780m away from Sun.

Saturn will be 12cm in diameter at a distance of 1.43Km from the Sun.

Uranus and Neptune will have a diameter 5cm. The former would be placed at a distance of 2.87Km and the later at 4.5Km.

It is evident from the above numbers that the scale model with this scaling factor demands a track that is at least 4.5Km in length. Because of the space constraint, the scaled down models of the solar system objects are not placed as per their scaled down distances.