Light from the Moon

Research the Moon for a month in the twinkling of an eye……………

Watch the YouTube Phases of the Moon video and then watch the YouTube Moon Phase and Libration video.

Spot the difference between the two Moon-months? Can you explain why they are both correct even though they are different?

If you are stuck for an answer, go to:
(The children in this school explain the reason for the difference very well.)

There are lots of things to measure about light from the Moon but it is difficult to do for real because it takes a month of cloudless nights! So we use a model to help us research. The light probe measures the reflected light from the ball in the same way that astronomers measure the light from the Moon.

To understand more about the phases of the Moon, Todd Timberlake has created a super demonstration of the Moon going round the Earth showing how the moon is illuminated by the Sun.

You can download this Phases of Moon demonstration directly from the Physics To Go website or by clicking here.

The Phases of Moon model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Once downloaded, double clicking the ejs_MoonPhases.jar file will run the program if Java is installed.

The Amount of Light Reflected from a Model Moon

Set up a model of the Moon, Earth and Sun. Use it to measure the amount light which is reflected from the model Moon as it goes around the model Earth. Light from the torch acts as light from the Sun.


Click here if you need help setting up and using a model Moon.

Download and watch the Phases of Moon demonstration directly from the Physcis To Go website or by clicking here. Decide on about 8 model Moon positions to take readings. Use the light probe to measure the amount of reflected light from the model Moon. For each position, find out what the angle is between probe, Moon and Sun.

For each position you investigate you should:

1 Find out the how many days it is after a New Moon.
2 Click on the picture below showing the phases of the Moon over 28 nights.
3 Use this collection of pictures of the Moon on the different days to estimate the fraction of the Moon that is lit up in your investigations. Print this page and write each fraction as a decimal in the chart on the appropriate days.
4 Record your data in a table or spreadsheet on your handheld. Click here to see how you should create your datasheet.
Create a graph of your results.
5 You could create a graph. Describe what the graph looks like.
  Pictures of the Moon over 28 days