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Creating Craters


Active Time
10-20 Minutes

Total Project Time
10-20 Minutes

Key Concepts
Crater, Meteorite, Energy


How did the Moon get its craters? What about the craters on Earth? Why do they look the way they do? Find out in this fun science activity, as you make your own craters by dropping balls into a tray of flour. 

This activity is not recommended for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data.


  • Large baking pan or shallow cardboard box
  • Flour (enough to fill the pan)
  • Cocoa powder (enough to create a thin layer on top of the flour)
  • Sieve or sifter
  • Balls of various sizes
  • Optional: ruler and meter stick

Prep Work

This project is messy—if possible, you should do it outside. If you must do the project inside, lay down a sheet or towels first to make clean-up easier.


1. Fill the baking pan with flour.

2. Use the sieve to put a thin layer of cocoa powder on top of the flour.

3. Try dropping a ball into the pan from about half a meter above it (optionally, use the meter stick so you can drop from a consistent height).

4. Look at the resulting impact crater. What color is the surface immediately around the crater? How does that compare to the surface of the rest of the pan? How far did the flour and cocoa powder spread? Optionally, use the ruler to measure these distances.
5. Try dropping the same ball from a different height. What does the resulting crater look like?

6. Try dropping balls of different sizes from the same height, and examine the resulting craters.

7. You can even try throwing a ball sideways so it hits the pan at an angle, instead of coming straight down. How is the resulting impact pattern different from when you dropped the balls straight down?

8. If needed, smooth out the surface of the pan, and sift a fresh layer of cocoa powder on top.


If you did the project inside, vacuum or sweep up any flour and cocoa powder that got on the floor.

What Happened?

You should have found that the bigger the ball, or the faster it was moving, the bigger the resulting crater would be. This is because larger, faster-moving balls have more kinetic energy than smaller, slower-moving balls. This energy is transferred to the flour and cocoa powder when the ball hits the ground, causing it to fly outward, creating the crater (and a mess!). You should also have seen that the impacts churned up the “soil,” bringing some of the white flour to the surface near the impact site. While the pattern around the crater was probably symmetric if you dropped the ball straight down, sideways impacts would result in asymmetric patterns as more flour/cocoa powder were thrown in one direction than the other.

Digging Deeper

Craters are round, bowl-shaped depressions surrounded by a ring, like the one shown below.
Impact craters are made when a meteorite crashes into a planet or moon (as opposed to volcanic craters, which are created when a volcano erupts). Just like in your science experiment, the size and shape of the crater depends on how big the meteorite was and how fast it was going when it hit the ground. A bigger, faster-moving meteorite will create a bigger crater, sometimes throwing material very far away from the impact site.

Some of the craters on the Moon are so big that you can see them with the naked eye! While Earth has over 100 known impact craters, not all of them are obvious. Unlike the Moon, Earth has an atmosphere with weather that causes erosion (wind and rain), along with animals and plants that can move soil and change landscapes over time. So, some craters on Earth’s surface may be eroded or overgrown. Many meteoroids (they are called meteoroids while they are still in space, and meteorites once they hit the ground) also burn up in Earth’s atmosphere, never reaching the ground at all.

For Further Exploration

  • Scale this project up! Do you have access to a sandbox, a shovel, and some dirt? Try the project outside. Create a large pile of loose material: dirt covered with a layer of sand (similar to the flour covered with cocoa powder). Ask an adult for help dropping a larger ball, like a basketball, from a higher location (like standing on a ladder).
  • For a more colorful project, use colored sand or sprinkles instead of cocoa powder. Create a rainbow of different layers, or different patterns on the surface, as shown in this video. What do your resulting craters look like?
  • Do you have a smartphone with a slow-motion camera setting? Try filming your meteorite impacts in slow motion! What do you see when you watch the videos?
Credits to:

All information and details are property of Science Buddies.
For more amazing projects and information please visit ScienceBuddies.org

Flying Helicopters on Mars


Active Time
10-20 Minutes

Total Project Time
10-20 Minutes

Key Concepts
Lift, Aerodynamics, Weight, Gravity


During the Mars 2020 mission, NASA plans to explore the surface of Mars using a rover in combination with a lightweight helicopter. To be able to fly on Mars, this helicopter must be super light and have very efficient blades. If not, it will never generate enough lift to get off the ground. In this activity, you will make your own paper helicopter and test different blade designs. Will your findings be reflected in NASA’s design? Try it out and see for yourself!

This activity is not recommended for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data.


  • Computer with access to a printer to print the paper helicopter template. (If you do not have access to a printer, you can use a ruler and pencil to draw your own paper helicopter template based on the online one.)
  • Printer paper
  • Scissors
  • At least 2 identical paper clips
  • A safe, high place from which to drop the paper helicopter. (You could have an adult help you stand on a chair or choose a balcony with safe railing, for example.)

Prep Work

  1. Download and print the paper helicopter template. If you do not have access to a printer, you can download the file and open it on your computer. Then use a pencil and ruler to draw the paper helicopter shapes on a piece of paper, based on the dimensions in the template.
  2. Follow the directions on the template to cut out and fold both paper helicopters.
3. On each paper helicopter, slide one paperclip over the folded tab at the bottom.


1. Hold the paper helicopter by the middle with the paper clip facing down, then let it go from high up. If it does not spin down, have an adult help you drop one of your paper helicopters from a safe, elevated location (such as while standing on a chair or a step stool, from a balcony, etc.)

2. Compare the two paper helicopters.

3. Try it out!

4. Drop each paper helicopter a couple more times from the same height.

5. As your helicopter starts to rotate, the spinning blades generate lift that slows it down. When you look carefully, you may notice this. Drop a paper helicopter and pay attention during the first fraction of a second before it starts to spin. Compare how fast the helicopter falls during that fraction of a second to how fast it falls once it starts spinning.

6. Because Mars’s atmosphere is about 100 times thinner than Earth’s atmosphere, it is much harder for a helicopter to create enough lift to get off the ground. Engineers had to change the blade design to create more lift so the helicopter could fly in Mars’s thin atmosphere. You have two paper helicopters where only the blade length is different.

7. Blade length is just one way to change the helicopter design.

8. Look at all your test results.

9. Compare your findings with the illustration of the helicopter Ingenuity on the surface of Mars (illustration from NASA). This helicopter will fly around and help NASA’s Perseverance rover explore Mars.

What Happened?

When you drop a paper helicopter, it will take a fraction of a second for it to start spinning and slow down. Did you notice how it fell faster before it started spinning? Once the paper helicopter spins, it should generate a push called “lift” which slows its descent to the ground. The paper helicopter that has shorter blades should fall faster because the shorter blades do not generate as much lift.

There might not be one single design for a paper helicopter that allows it to descend the slowest. That said, longer and wider blades that hit the air at an angle are generally better. These changes to the blades generally create more lift, and as a result, slow down the fall of the paper helicopter more. If you change the dimensions of your paper helicopter too drastically, however, your helicopter may actually become unstable and perform worse.

Due to its thin atmosphere, the blades of a Mars helicopter’s must be bigger and spin faster than they would on Earth in order to generate enough lift. NASA’s Ingenuity helicopter is very lightweight—only 4 pounds (on Earth)! Each blade is about 2 feet (0.6 meters) long, and the blades rotate about 2400 times per minute. A solar panel powers the helicopter and it operates autonomously. It is designed to land safely on the uneven Martian terrain. This way, it can help NASA’s Perseverance rover explore the Martian surface.

Digging Deeper

Mars’s gravity is much weaker than Earth’s (about 38%). This means that while the Ingenuity helicopter weighs 4 pounds on Earth, it only weighs about 1.5 pounds on Mars! You might think that this makes it much easier for the helicopter to fly. However, Mars’s thin atmosphere actually makes it more difficult. A helicopter needs air to fly. Air is made up of tiny particles that bounce around and press against everything around them. When the particles flow over a spinning helicopter blade, they collectively press up on the bottom of the blade harder than they press down on the top. This generates a net upward push, called lift. In general, the more particles there are packed closely together, the harder they can press on surfaces. In the thin Martian atmosphere, the particles are spaced much farther apart. In order to take off, the lift generated by the helicopter must be bigger than its weight, the force of gravity pulling it down. The reduction of lift due to the thinner atmosphere is much larger than the reduction of weight, therefore, in the thinner Martian atmosphere, the blades must be bigger and spin faster than they would in Earth’s thicker atmosphere.

Other factors, like changing the shape or angle of the blades, can also influence lift. You may have experimented with some of these factors with your paper helicopter designs. Your paper helicopters did not generate enough lift to fly upward, but the lift helped slow their descent. The more lift they generated, the slower they fell.

For Further Exploration

  • Make paper helicopters out of other types of paper. Does the type of paper make a difference?
  • Look up how to make a hand propeller toy and explore the effect of changes on the rotor blade design.
  • Can you make the blades of your paper helicopter turn in the other direction?
  • Use a stopwatch to time how long it takes for each paper helicopter to fall from a fixed height. The longer it takes, the slower the helicopter falls. Instead of a stopwatch, you can also film a slow-motion video and count the number of frames it takes for the helicopter to fall over a specified distance. The more frames it takes, the slower the helicopter falls. To calculate the time, divide the number of frames by the frame rate at which the slow-motion video was recorded. Many smartphones record slow-motion video at 120 or 240 frames per second, but you will need to look up this number for your phone. For example, if you counted 30 frames and recorded a rate of 120 frames per second, the fall took 30/120 or 0.25 seconds.
Credits to: Sabine De Brabandere, PhD, Science Bubbies

All information and details are property of Science Buddies.
For more amazing projects and information please visit ScienceBuddies.org

Stomp Rockets


In this activity, students will:

  • Work individually or in teams of two to construct and launch paper rockets using a teacher-built PVC-pipe launcher.
  • Following the flight of their rocket, calculate the altitude their rocket achieved.
  • Based on the flight performance of their rockets, analyze their rocket designs, modify or rebuild them, launch again, and calculate the altitude achieved to determine if their changes affected the performance of the rocket.
  • Conclude the activity by writing a post-flight mission report


  • Paper Rocket
  • Student Instructions (0ptional)
  • 2 sheets of 8.5×11 – inch paper (white or color) OR custom skins
  • Cellophane tape OR masking tape
  • Scissors
  • Markers for decorating/naming rockets
  • 24 inch length of 1/2-inch PVC pipe (for the rocket form)
  • Stomp rocket launcher
  • Stopm Rocket ASssembly Instructions Download PDF
  • 5 foot lenght of 1/2-inch PVC pipe cut into various lenghts (see assembly instructions)
  • 2 PVC 45-degree elbows slip connectors
  • 2 PVC tee slip connectors
  • 2 PVC slip caps
  • Duct Tape
  • Empty 2-liter bottle(plus spares if available) 
  • String OR Thread
  • Penny or similar weight
  • Paper clip



Prepare for the lesson by watching the “Do It Yourself Space: Stomp Rockets” videos available above.

Prior to launch day, construct at least one rocket launcher. Take the Stomp Rocket Launcher Assembly Instructions to a hardware store to make purchasing the right pieces easy. While at the hardware store, purchase enough 1/2-inch PVC pipe to make the launchers and the rocket forms. If you do not own a PVC cutter, it’s a good idea to purchase one or ask the hardware store to pre-cut the PVC pipe for you in the specified lengths. You may also use a fine-tooth saw to cut PVC.

Safety Note: Use caution when cutting the PVC for the launcher and rocket forms.

Building The Rockets

1. Roll a piece of 8.5 x 11-inch paper snuggly (but not too tightly) around a 24-inch length of 1/2-inch PVC pipe. Optionally, use one of the custom skins.

2. Tape the paper to itself (but not to the PVC pipe). Use enough tape to completely seal the seam, making the seam airtight. This will be the body, or fuselage, of your rocket.

3. Slide the fuselage off the PVC form. Verify that the fuselage slips easily from the PVC form so that it will fit on the launch tube later.

4. Make a nose cone either by pinching one end of the fuselage, folding it over and taping it to the rocket body; or by cutting out a 3/4 circle, rolling it into a cone shape and taping it to the fuselage. Optionally, use the custom nose-cone template. Secure the nose cone using plenty of tape to make the rocket airtight. (Blow through the rocket from the bottom to check for leaks

5. Cut out fins (of any shape) and attach them symmetrically to the lower part of the fuselage (opposite the nose cone), leaving the opening at the bottom of the fuselage open and clear of tape.
Allow students to experiment with the size and shape of their rocket fins. Through repeated flights, students will discover that proportional, firm fins will provide the most stabilization to their rocket and eliminate drag.

6. Have students color and name their rockets to differentiate them from other rockets in the group.

Launching The Rockets

When headed out to launch, always have spare empty 2-liter soda bottles and duct tape handy. Though some bottles will launch 20 to 40 rockets, bottles will eventually fail and will need to be replaced. 

Because of their lightweight design, stomp rockets perform best on non-windy days. If you are located in a windy location, try to orient your launch location behind a windbreak such as a gymnasium or other large building.

Secure an outdoor location that is clear of overhead obstructions (trees, building roofs, power lines, etc.) and has a ground area of at least 100 meters by 25 meters for best altitude-tracking results. A shorter, 50-meter or 25-meter baseline may also be used.

If calculating altitude using tracking stations A and B, place the rocket launcher at the midpoint of a 100-meter baseline. If estimating altitude using local markers such as marks on buildings, orient the rocket launchers and observers appropriately.

Stomping: Be sure students stomp on the bottle across the bottle label, perpendicular to the body of the bottle. This is the most flexible zone of the bottle and allows for it to be reused numerous times. If students stomp on the bottom end of the bottle, it will often shatter, rendering the bottle unusable.

Aiming: The PVC legs of the launcher are different lengths. This allows for adjustment on uneven ground and aiming the launch into the wind if you are launching on a windy day. (Launching into the wind will compensate for rocket drift and make rockets easier to track and retrieve.) Additionally, horizontal distance competitions can be held and launch angles adjusted. Place a basketball in the landing zone, have students imagine the ball is Mars, and launch their rocket to Mars! If performing horizontal launches, a large indoor space such as a cafeteria or gymnasium may be used.

Re-inflating the bottle: Bottles can be easily re-inflated using air from your lungs. Place your hand in a fist around the open end of the launch tube and blow into your fist to re-inflate the bottle. Using your fist protects you from the unsanitary conditions that may exist on your rocket launcher.

All information and details are property of NASA Jet Propulsion Laboratory.
For more information please visit NASA Jet Propulsion Laboratory


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