Class 4 - Solar System work!

This week in Science we have begun looking at the topic of 'Space'. We started by learning about early astronomy, such as the Greek astronomer Ptolemy who believed that all planets orbit the Earth and that the Earth doesn't move - the 'Geocentric theory'. 

To help us visualise the scale of the solar system we also used a roll of toilet roll to demonstrate how far apart relatively each planet is! The inner planets fitted comfortably in the classroom but we soon had to go out on the yard to fit more planets in and then finally, to include Neptune, we had to stretch out the toilet roll almost across the full length of the school field - from this demonstration we could clearly see why some planets are labelled 'inner' and others 'outer', as well as the relative distances. 

This was the launch, pun intended, for our next piece of work - to draw a scaled representation of the orbits of the planets around the sun. 

We started with some measurements which were all scaled so that the radius of Earth's orbit was equal to '1' - pupils then decided what one unit was worth - they had to be careful though as the radius of Neptune's orbit was thirty times that of Earth's! We took giant pieces of paper and began creating our images. 

 Using chalk and string we were able to construct circular orbits, keeping the radius consistent. This was a great way to bring in the terminology for circles which is part of the new Maths curriculum (e.g. diameter, radius, circumference).

 This group were first to finish stage one of the task. They opted to put the sun in the corner of their work to allow them a larger scale.

 Adding the planets....

 Then we began the next challenge - plotting the movement of each planets using statistics of the orbital velocity relative to that of Earth's. For example, if Earth travels a distance of 1, Neptune would have moved a distance of 0.182 in the same time. This meant that we we could plot the Earth's movement in say 10 cm steps and do the same for the other planets (e.g. Neptune would move 1.8 cms in the same time). Here you can see scaled markings on the diagram to plot the relative, scaled movement.

We hope to take use this piece to create a short animation film demonstrating both how the planets orbit around the sun and how their speed is relative to how far away they are from the sun. This was quite ambitious work but we've done well so far so I'm optimistic that at least one of the groups might take this next step and capture the animated version!