Khagol Mandal

The Sun, Moon and Earth System

This is a huge working model of the sun, moon and earth system. It shows four motions - the earth's revolution, earth's rotation, the moon's revolution and the precession motion of the earth's axis. The phenomena occurring due to these motions can be explained using the model. They are --

• occurrences of eclipses
• occurrences of eclipses only on some full moon and new moon days
• Kepler's laws of planetary motion
• occurrences of six month long day and six month long night on the north and south pole of the earth
• occurrences of seasons on the earth
• precession of the equinoxes
• changing of the north pole star of the earth
• rotation of the equinox and solstice points
• the same side of the moon constantly facing the earth irrespective of its revolution around the earth

Complete view of Sun Moon Earth Model

Not everyone is able to visualize the above mentioned phenomena or understand them quickly. It might take some days to properly understand them but with this model I can explain them in just 30 minutes. The explanation is not with a chalk and board but with a 3D model existing in solid reality. You can feel it, move around it, view it from different angles, go near the sun, moon or the earth to see how the other bodies would look from that point.

In February 2001, the model was taken to IIT Kanpur for the Astro modeling competition in the Techkriti 2001. festival. It bagged first prize at all India level. The director of the Nehru planetarium, Delhi had come there for giving a seminar and was very impressed by the model. She even asked to make a similar model, bigger in size, to be put up in the planetarium.

Abhir Joshi explaining the model to the curious onlookers which include Dr. Jayant Naralikar.