Impact 
Reid Phillips
Jesse Scott
Ed Park

Introduction | Procedure | Results | Conclusion | Related Sites | Return to Research Page

Background Information

The term meteor comes from the Greek meteoron meaning phenomenon in the sky. It is used to describe the streak of light produced as matter in the solar system falls into Earth's atmosphere creating temporary incandescence resulting from atmospheric friction. This typically occurs at heights of 80 to 110 kilometers (50 to 68 miles) above Earth's surface. The term is also used loosely with the word meteoroid referring to the particle itself without relation to the phenomena it produces when entering the Earth's atmosphere. A meteoroid is matter revolving around the sun or any object in space that is too small to be called an asteroid or a comet. Even smaller particles are called micrometeoroids or cosmic dust grains, which includes any space material that should happen to enter our solar system. A meteorite is a meteoroid that reaches the surface of the Earth without being completely vaporized. Small or big, when a meteor hit’s the earth’s surface it makes some kind of crater depending on the size and velocity of the object.

Statement of the Problem

The purpose of this experiment is to find out whether the velocity of a meteor will make a difference in the size of the crater it creates upon impact.

Review of Literature

In the book Comets, Asteroids and Meteors, Robin Birch states that the approximate size of the crater depends on the size and speed of the meteor (Birch). Small diameter meteorites (less than 4 kilometers or 6.4 miles) usually leave a round bowl crater, while larger meteorites cause craters with raised centers called the central peak. This peak is caused by the surface's attempt to rebound from the impact. Huge impacts can leave multiple rings in the earth's surface in the same way a rock creates ripples in a pond (Kathleen 12). Melosh and Collins, the featured scientists in Stiles’ article, both state that the crater made by a meteor made 50,000 years ago was traveling at enormous speeds. That velocity is almost four times faster than NASA's experimental X-43A scramjet -- the fastest aircraft flown -- and ten times faster than a bullet fired from the highest-velocity rifle, a 0.220 Swift cartridge rifle. The size of the meteor which was a pit 570 feet deep and 4,100 feet across – enough room for 20 football fields, wouldn’t have made that big of crater if not traveling at the speed it was going. The intact half of the Meteor Crater meteorite exploded with at least 2.5 megatons of energy on impact, or the equivalent of 2.5 million tons of TNT (Stiles). The Exploration website also states that the shape and size of the crater depends on the size and velocity of impact (Bray). When the velocity of a meteorite gets so high it creates heat which will cause the impact to be much larger and stronger than a meteorite traveling at lesser speeds (Norton 6). All of this seems to suggest that as the velocity of a meteor increases so will the size of its crater.



Hypothesis

In our experiment we will replicate a meteor impact by dropping a marble from various heights into a bowl full of flour. We believe that as the vertical velocity (feet per second) of the marble increases as a function of the height, the diameter of the crater left in the flour (inches) will also increase.

Method | Back to Top

Materials needed were flour, baking pan, marble, ruler, measuring tape, and a ladder/stool. The procedures occurred like so: first we poured flour into the baking pan several inches deep, so when we dropped the marble it would not hit the bottom of the pan. Then using a measuring tape we measured how far off the ground the flour was leveled off at. Then we decided we would measure drops from 1 ft, 3 ft, 5 ft, 7 ft, and 9 ft. We used the measuring tape so we knew how high we were and added the height of the flour so we weren't measuring short of our total dropping distance. When everything was set we dropped the marble into the flour, measuring the diameter of the crater created. We repeated the drops several times from each height. When removing the marble try not to obstruct the crater that is left. 

Results | Back to Top

The results of our experiment are expressed in the data table below. We were able to convert height into velocity using the equation velocity = sqrt(2*9.8*height).

                                                                           data link
Especially when graphed, it is plain to see that our hypothesis was correct. As the velocity of the increased, so did the diameter of the crater.

                                                

                                                    data link
Through the fitting of a “best-fit-line” to the graph we were able to define the relationship between the velocity and the diameter with the following equation.

3.17x3 - .01x2 + .20x +.41

The correlation coefficient was found to be .97.

Conclusion | Back to Top

It is clear to see that our hypothesis was correct. The velocity was in relation to the diameter of the crater. That also brings up the fact that our results aren't very close to what would actually happen. The mass of the crater, its shape, the density of the earth, would all also affect the size of the crater. Further research would need to include aspects of all of the things mentioned. But for a high school project that would be very complicated.

Related Sites

Earth Impact Database

    This site provides information on a very large number of impact events dating with detailed information on research done since 1955.

Impact Event (Wikipedia)

    This provides a brief and general overview of impact events. It is great for obtaining a beginner's understanding of meteor impacts.

Meteors, Meteorites, and Impacts

    This site very directly relates to our experiment. It goes into great detail about the effect of the other variables mentioned in our conclusion.