How can airflow move lunar-like ejecta, and where does a tabletop model stop matching the Moon?

How can airflow move lunar-like ejecta, and where does a tabletop model stop matching the Moon? · Student Data Sheet

Question: What can a safe airflow model reveal about loose surface material near a descending lander, and what important lunar-plume physics does it leave out?

Hypothesis: If nozzle height changes while the same contained air stroke and surface are used, then the number and distance of moved paper markers may change because the airflow spreads and weakens differently before it reaches the surface, because flow direction and distance affect how much momentum reaches the markers, although this room-air setup is not a scaled rocket plume.

Materials

• clear lidded plastic tray
• 20 large paper squares about 1 cm across
• textured paper or cloth tray liner
• blunt plastic syringe with no needle or an adult-approved hand bulb
• ruler, marker, timer and data sheet

Safety before starting

• Use only large paper squares in a clear tray. Do not use sand, flour, ash, talc, glitter, powders or any fine material that could become airborne or be inhaled.
• Use a blunt plastic syringe with no needle or an adult-approved hand bulb. Never use compressed-air cans, fans, leaf blowers, engines, combustion or rocket motors. Keep the airflow aimed into the tray and away from faces.
• Keep the tray on a stable desk, use the lid or guard when it permits safe observation, and stop if markers leave the tray or the setup becomes unstable. Follow classroom rules for cutting paper and cleanup.

Lab notes

• Use only large paper squares; do not use sand, flour, talc, ash, glitter or any powder/aerosol that can be inhaled or become airborne.
• NASA's 2026 article distinguishes the first ethane plume simulation system, which heats but does not burn and has about 100 pounds maximum thrust, from a later hybrid motor test. Do not describe the first system as a hot-fire engine test.
• The NASA JPL supercomputer project demonstrates coupled plume/soil modelling; its simplified Earth/Mars context and model state must not be treated as a universal lunar landing prediction.

Variables

Independent: Height of one blunt air nozzle above a fixed target surface · Dependent: Movement of large visible paper markers after one controlled air stroke

Keep constant: Use the same no-needle syringe, start/end volume marks and one-second stroke, vertical nozzle angle, bin, surface, paper size/count, nozzle center and radius measurement; reset the same 20 markers between trials

Procedure

1. Set up a no-dust model in a tray: Use a clear plastic bin with a textured paper or cloth floor. Cut 20 large paper squares about 1 cm across and place them in the same marked target area; do not use flour, sand, powder, ash or fine particulate. Mark a 5 cm circle around the target center. Put the bin on a stable desk and keep the lid or guard in place if it still allows safe viewing.
2. Standardize one gentle air stroke: Use a blunt plastic syringe with no needle, or an adult-approved hand bulb. Keep the nozzle vertical at the center. Mark two syringe positions and move the plunger between them over one second; use the same stroke for every trial. Never point the airflow at a person. If a one-second stroke cannot be repeated, switch to a published-data-only comparison and say why.
3. Run randomized nozzle heights: Test nozzle heights of 2, 4 and 6 cm, measured from the surface to the nozzle tip. Randomize the height order. For each height, reset the same 20 paper squares to the starting pattern and perform five strokes. After each stroke, count squares beyond the 5 cm circle and measure the farthest square from the center. A zero movement result is valid data.
4. Separate repeatability from model realism: Calculate the mean and range of marker counts for each height, but preserve all five raw trials. If one stroke moved more pieces because it was faster or off-center, mark it and repeat only under a predeclared classroom rule. Do not convert the paper motion into lunar particle speed, plume pressure, crater size or damage radius.
5. Compare with actual NASA testing: NASA's 2026 plume-surface campaign uses instrumented tests in a 60-foot spherical vacuum chamber with a tray of simulated lunar regolith. Its first ethane plume system heats but does not burn and produces about 100 pounds of thrust; tests record crater formation and ejecta distribution, angle, height and particle speed. A NASA SCALPSS camera demonstration also imaged a real Blue Ghost lunar landing. These engineering tests, not the classroom tray, examine the mission-relevant physics.
6. Name what the airflow model cannot reproduce: The classroom stroke travels through Earth's atmosphere; lunar tests use vacuum conditions, real or validated regolith simulant, engine-specific exhaust, low lunar gravity, fine angular grains, electrostatic and gas-particle effects, and high-speed instruments. The paper pieces are much larger and lighter than dust grains. This setup is a qualitative flow analogy, not a scale model or a landing-safety test.

Record your observations

Classroom analogy versus lunar landing test

Answer key and expected pattern

The air stroke may move some paper pieces, and the pattern may change with nozzle height; the measured result depends on the exact tray, nozzle, stroke and paper markers.

NASA's 2026 vacuum campaign measures several engineering outcomes that the classroom setup cannot measure: crater formation, ejecta geometry and particle speeds.

The model can support a qualitative claim about directed flow moving loose surface markers, but not a quantitative prediction for lunar dust, lander damage, visibility or safe landing distance.

Remember: A paper model can show airflow moving markers; it cannot predict what rocket exhaust will do on the Moon. Use the classroom evidence only for its tested air-and-paper setup, and use vacuum tests and validated plume/regolith models for lunar landing risk.