Making Craters in Flour

An adult should be present. Drop the marbles while standing on the floor, from no higher than an adult's raised arm; never climb on furniture and never throw them. Marbles are a choking hazard for small children. Do not eat the flour: raw flour can carry germs such as E. coli, so wash your hands afterwards.

Protective equipment and “do not substitute” warnings have not been recorded for this experiment yet. They are added when its safety review is completed; until then, follow the supervision notes above.

Disposal: Do not reuse the flour for food. Put it and the cocoa in general waste, and recycle the newspaper.

Do not start this experiment until an adult who has read the supervision notes above is present.

An adult needs to be here first

The materials (6) and steps (5) for this experiment are hidden until an adult who has read the safety information above is present.

What you should see

• Each impact makes a round crater with a raised rim.
• White flour is thrown out over the dark cocoa in streaks and rays around the crater.
• Higher drops (faster impacts) make wider craters.
• The larger marble makes larger craters than the smaller one from the same height.

Why it works

The Moon's craters were made when asteroids, meteoroids and comets crashed into its surface. How big a crater is and what it looks like depend on the energy of the impact, which depends on the impactor's size, density and speed. In your tray, a higher drop means a faster marble and a larger marble carries more energy, so both make bigger craters.

The Moon has no atmosphere, so no wind or weather wears its craters away, which is why so many old craters can still be seen.

Learn the ideas behind it

• Energy
• Gravity
• Solar System

Explore it further

The same ideas, as something you can change and watch on screen:

• Gravity & Orbital Motion (simulation)
• Solar System Explorer (3D)

Sources

• Moon Craters — NASA Science
• Why Does the Moon Have Craters? — NASA Space Place
• NASA STEM Activity: Impact Craters — NASA
• Raw Flour and Dough — US Centers for Disease Control and Prevention