Have you ever wondered how the Moon changes shape each night? Or maybe you’ve wanted to know why it changes.
Actually, it doesn’t change shape at all, but it does look different! In this activity, we use observation to find out more about our marvellous Moon.
The Moon is Earth’s natural satellite. It takes about a month (27.3 days) to revolve around the Earth. The Moon also spins on its axis, completing one rotation in about the same time it takes to revolve around the Earth.
This means we always see the same side of the Moon from Earth.
Even though it looks bright to us, the Moon doesn’t actually produce its own light. It reflects the Sun’s light towards the Earth. As the Moon revolves around the Earth, the side of the Moon facing Earth is lit with different amounts of sunlight every night. This makes the Moon appear to change shape, which we call the phases.
When the Moon is between the Earth and the Sun, the Sun shines on the side of the Moon facing away from Earth. There is no sunlight reflecting off the Moon back towards us, so we cannot see the Moon. We call this the new Moon.
When the Moon is directly opposite the Sun, the Sun shines on the side of the Moon facing towards the Earth, illuminating a circular shape. We call this the full Moon.
Between those phases, the Moon goes through the phases of waxing (increasing), waning (decreasing) and quarter.
We describe the shape of the moon as crescent if less than half of it is visible or gibbous (swollen) if more than half of it is visible.
Research the different phases of the Moon. In your Moon journal, mark where you think the Moon will match these phases: new Moon, waxing crescent, first quarter, waxing gibbous, full Moon, waning gibbous, third quarter and waning crescent. Use your research to name the phases of the Moon as you identify them in your journal.
Activity 1: Let’s investigate
What you’ll need
5 minutes every day for one month
paper (to make your journal)
Create your Moon journal by drawing 4 lines of 7 circles: that’s one circle for each day of the week for 4 weeks (see an example by NASA).
What you’ll do
Head outside to observe the Moon each day for one month.
Write down the date and time you make each observation, and illustrate how the Moon looks each day by shading in the circles on your Moon journal to match the shape of the Moon.
If you can see the whole Moon, you do not need to shade in any part of the circle. If you can only see half of the Moon, shade the side of the Moon that you cannot see in the circle for that day.
What to look for:
Does it look the same as yesterday? How has it changed?
What shape is it today? What shape do you think the Moon will be tomorrow?Why?
What do you think will happen to the Moon’s shape during the next week?
If you’ve been inspired by this activity, keep observing the Moon phases for another month. Continue the Moon journal or create a new one.
At the end of the second month of observation see if you can answer these questions:
How many days are needed to go from one full Moon to the next? What about a new Moon?
Can you predict when the next full Moon will be?
What do you think will happen to the Moon’s shape in the sky during the next week?
There are more than 200 moons in our Solar System. They come in many shapes, sizes and types.
Some planets, like the gas giants Saturn and Jupiter, have dozens of moons. Others, like Mercury and Venus, have none. Earth has one – and we call it the Moon because for a long time it was the only one we knew about.
Research some of the moons in our Solar System. You might like to look up:
Phobos or Deimos (Mars)
Ganymede, Europa or Io (Jupiter)
Enceladus or Titan (Saturn)
Look for details like:
What does it look like? What colour is it? How large is it compared to our Moon?
What interesting features does it have – craters, oceans, ice volcanoes? How have these features formed?
Describe the atmosphere on this moon. Why are atmospheres of different moons so different?
Where does its name come from? What does it mean?
Create an art piece based on the moon you think is most interesting. It could be a painting, a collage or a model. Make sure you add the special features that you learned about!
Can you think of a way to illustrate the different phases of the Moon? Maybe you could make a model or an animation, take photos to create a timelapse, or even bake them! Share your project with friends or family.
We’d love to see what you create! Share your video or animation by tagging #ScitechAtHome on social media.
Try another at home challenge from our postcard series: