Impact Craters Simulation Objective: To investigate how the size and shape of impact craters is related to projectile size, projectile weight, projectile velocity and the angle of projectile impact. Equipment: A bucket or tub of fine, dry sand. A cup of fine, dry sand of contrasting colour. A flour sifter or salt shaker. Projectiles: ball bearings, marbles, lead fishing weights, or something small and heavy. Method: 1. Shake the bucket or tub of sand to level the sand. 2. Put a light dusting of the contrasting colored sand over the top of the sand in the bucket using the salt shaker or sifter. 3. Drop projectiles from different heights and observe the craters they produce in the sand. 4. Make note of the size and weight of the projectile and the height from which it was dropped. 5. Measure the width of the craters from a point on the peak of the rim to a point on the rim on the opposite side of the crater. 6. Measure the height of the craters from the deepest point to crater rim. 7. Plot all the measurements using scattergraphs. Remember to put the independent variable on the horizontal axis and the dependent variable on the vertical axis. Hypotheses: Make a hypothesis for each of the following questions and then answer them from the results of your experiments: Is the crater the same size as the projectile? Is it larger or smaller? If a projectile is thrown into the sand at an angle does it produce a round crater? How does the size of the crater depend upon the weight of the projectile when two projectiles are dropped from the same height? How does the size of the crater depend upon the height from which it is dropped when the projectiles have the same weight? Estimate the relative volumes of the ejecta (the material ejected out of the crater) by calculating the cube of the crater diameter. Millimetres are convenient units for measuring the diameters of these craters. Compare the volume of the ejecta to the energy (weight times height) of the projectile. How do they compare? Justification/Geological Background: Use your initial research to help explain briefly your predictions above. Use this excellent resource (Meteorite Impact Structures:the good and the bad) to help initially with your hypotheses but more importantly with your analysis. Interpretation: For each experiment draw a graph and briefly annotate on it the general pattern, giving maximum & minimum figures, and any anomalies etc. Describe your findings in words. Explain why these patterns and anomalies occurred. Compare your findings with text books and results from other research investigations. Locate a map of the Moon. Relate your data to the various craters that you see on the Moon, and try to predict what type of meteor may have caused some of the craters Sum up your findings with a conclusion, referring back to your original hypotheses. Evaluation: How reliable was the experiment/procedure/equipment? What problems or limitations were there with the experiment? Where did it not fit in with real life situations? How does making craters in sand helps us understand real meteorite craters? What improvements could be made? What problems did you encounter as you tried to measure the craters? How did you deal with those problems? How reliable are the results and your recording of the results? What improvements could be made to improve the recording reliability? How could the investigation be extended? What new problems/questions/hypotheses could be put forward? What other variables could be tested?