Make your own Moon impact craters

Make your own Moon impact craters

This fun activity for family and kids brings to life the drama of meteor impacts on the Moon and is a great science project for school or at home.

Published: March 26, 2024 at 2:16 pm

We've all seen craters on the Moon, but have you ever tried to make your own Moon impact craters at home?

This simple astronomy arts and craft activity uses just flour, cocoa powder and plasticine and is a good introduction to how lunar craters and surrounding features are created.

Our Moon crater activity is great fun for all the family to get involved with, and makes for a great kids' science project for school or at home.

Read our guide on how to observe the Moon with the naked eye or a telescope

How Moon craters are formed

Ptolemaeus and Rupes Recta lunar craters John Brown, Leicester, 9 April 2022 Equipment: ZWO ASI290MC camera, Sky-Watcher Skymax 127 Maksutov-Cassegrain, Sky-Watcher AZ-GTi mount
Ptolemaeus and Rupes Recta lunar craters, photographed by John Brown, Leicester, 9 April 2022

Craters are formed when an asteroid, comet or large meteorite hits the surface of a planet or moon.

These objects can be travelling at speeds of up to 40 kilometres per second, so the impact is violent and the energy released can dramatically change the landscape around it within seconds.

The crater itself is usually circular, but in some circumstances oval-shaped craters can form. 

Commonly seen features at a Moon crater include:

  • Raised rim around the edge of the crater
  • Unstable material slipping down on the inside edge to form slump terraces
  • Blanket of ejecta material from below the surface that extends outwards by 2–3 crater diameters
  • Ejecta rays – like those at Crater Copernicus and Crater Tycho – which are straight lines of subsurface material extending outwards from the crater
Crater Tycho, as seen by the Hubble Space Telescope. Credit: NASA, ESA, and D. Ehrenreich (Institut de Planétologie et d'Astrophysique de Grenoble (IPAG)/CNRS/Université Joseph Fourier)
Crater Tycho and its famous ejecta rays, as seen by the Hubble Space Telescope. Credit: NASA, ESA, and D. Ehrenreich (Institut de Planétologie et d'Astrophysique de Grenoble (IPAG)/CNRS/Université Joseph Fourier)

What you need to make your own Moon crater

Lunar impact craters are usually 10 to 20 times larger in diameter than the object that created them.

But the ones we create won’t be that large because we can’t throw our impactors at the speed needed for such a dramatic effect!

However, we’ll still be creating craters with very similar features to those that you can see on the Moon. 

Flour is ideal for this project because it mimics the behaviour of lunar surface material pulverised by a violent impact.

It's lightweight,so it produces great ejecta features that stand out when a darker layer of cocoa powder is used as a surface covering. 

When making a Moon crater, the underlying white flour shows up well against the darker cocoa powder surface. Credit: Mary McIntyre
When making a Moon crater, the underlying white flour shows up well against the darker cocoa powder surface. Credit: Mary McIntyre

Cover the floor around the cake tin with a plastic or vinyl sheet to catch any stray material.

Your tin should be min. 4–5cm deep, or your impactors will hit the bottom and bounce, creating an unnatural crater. 

When it’s time to drop your impactors, hang a makeshift plumb line so you can centre the cake tin underneath.

Once the tin is in place, you can shorten the string so the end is 1 metre above the floor.

Hold your impactors at the end of the string before dropping, to ensure they’re falling from the same height.

After you’ve dropped from that height, shorten the line so the end is 1.5 metres from the floor and drop again. 

Photograph or sketch each crater and its features after impact to compare different sizes of impactors and different heights.

Follow our step-by-step guide below to make your own Moon crater.

What you'll need

  • Air-dry clay or Plasticine for making different-sized impactors
  • White flour – any kind will do. Alternatively, you could use fine white sand instead
  • Cocoa powder and a sieve to create the top layer of your lunar surface, contrasting the flour
  • Deep cake tin or oven tray. We used a 4cm-deep circular tin with a diameter of 20cm
  • A ruler longer than the cake tin diameter so you can level the top of the flour with one swipe

Step-by-step

Step 1

How to make a moon crater arts crafts science step 01Create some impactors by rolling the air-dry clay into different-sized balls and letting them dry.

We made four, with diameters of 1cm, 1.5cm, 2cm and 3cm.

If you don’t have clay, you can use Plasticine or similar material instead.

Step 2

How to make a moon crater arts crafts science step 02

Fill your cake tin with white flour or fine white sand, being careful not to pat it down and compact it.

Using a ruler, scrape across the top to create a level surface.

We did this step over a plastic box to make the clean-up easier.

Step 3

How to make a moon crater arts crafts science step 03

Using a small sieve or tea strainer, gently sprinkle some cocoa powder over the flour to create a thin and even covering across the entire surface.

Then position your tin on the floor, on top of the plastic or vinyl sheets.

Step 4

How to make a moon crater arts crafts science step 04

Drop the smallest impactor onto your lunar surface from a height of 1 metre.

Take photographs or make sketches of the resulting crater and note any features you see.

Carefully remove the impactor, fill in the hole and reset the surface.

Step 5

How to make a moon crater arts crafts science step 05

Repeat step 4 for the other three sizes of impactor, noting any new features that appear with the larger impactors compared to the smaller ones.

Photograph or sketch each new crater

Remove the impactor and refresh the surface before each drop.

Step 6

How to make a moon crater arts crafts science step 06

Repeat step 4, but this time drop your impactors from a height of 1.5 metres.

Photograph or sketch the results you get from each of the larger impactors.

Note how the increased height affects the height of the crater rim and the spread of the ejecta.

Have you completed our Moon crater craft project? Let us know by emailing contactus@skyatnightmagazine.com. This How To originally appeared in the August 2023 issue of BBC Sky at Night Magazine.

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