Impact Craters

Projectiles are dropped into a tray of powder to observe crater size, shape, and ejection patterns.

1. Fill a tray with 2 to 3 cm of flour or sand and level the surface. Sprinkle a thin, even layer of cocoa powder over the top.
2. Choose one projectile (candy, marbles, rubber balls, steel balls) and a drop height. Hold the projectile still at the chosen height over the center of the tray.
3. Drop the projectile straight down and let it form a crater. Do not throw.
4. Measure crater diameter and depth if possible. Note the ejecta pattern and any rays in the cocoa layer.
5. Reset the surface by gently shaking or smoothing the tray. Repeat with different drop heights, masses, and sizes to compare results.

“Impact Craters” Hands-on Activity Demonstration - Learn with NASA:

📄 Impact Craters - NASA STEM Search: https://www.nasa.gov/stem-content/impact-craters/

📄 Craters in the classroom - Las Cumbres Observatory: https://lco.global/education/activities/craters-in-the-classroom/

• Compare crater size versus drop height to explore how impact speed affects crater diameter.
• Test different projectile materials of the same size to isolate the effect of mass.
• Vary surface layers to model different soils
• Drop at a shallow angle to observe an elongated crater and an off center ejecta pattern.

• Wear safety glasses to protect eyes from airborne powder and bouncing projectiles.
• Keep faces and hands above the tray edges and drop objects vertically, not as thrown shots.
• Use small, smooth projectiles only; avoid sharp, heavy, or fragile objects that could shatter.
• Control dust by working slowly and cleaning up with a damp cloth; avoid inhaling fine powders.
• Supervise younger students and keep the work area clear of non participants.

• How do mass and drop height change crater diameter and depth? What does this suggest about impact energy?
• What differences do you see between vertical and angled impacts?
• How might crater floors or permanently shadowed regions trap water ice on the Moon?
• Which surface analog produced the largest or most defined crater, and what might that imply about lunar soil?
• How does your model differ from real impacts in vacuum and at very high speeds?