Investigating Earth and Moon Surface: Impact Craters

• Further the understanding and use of the Scientific Method as they make a model of the moon's surface and conduct an experiment using their skills of stating a question, forming hypotheses, experimental design, observation, recording data, drawing conclusions and thinking logically to explain the formation of impact craters.
• Allow students to do more of their own thinking as they work with partners who are at their own level of "expertise", and not rely so much on getting all the "right" answers by letting a more capable classmate do the thinking (thus the differentiated work pages).
• Students will practice the skills of working cooperatively, classroom safety, and careful use of materials.
• Using the metric ruler will reinforce the concept that the metric system is the globally accepted form of measurement and will review lessons taught earlier.
• Reinforce the concept that gravity is the force that pulls a smaller objects towards one another, and that the speed (velocity) of a smaller object rather than its distance from the larger is the cause of the size of the impact crater (as well as the size and shape of the incoming object).
• Review and introduction of vocabulary including metric terms "measure to the nearest _", impact crater, velocity, gravity.

This activity is appropriate for an upper intermediate (Gr.5) class of 20- 30 students working in small groups of 3-5. The physical experiment could also be done as a demonstration with the differentiated worksheets given to the appropriate groups. It has been prepared as a differentiated lesson in which 3 levels of academic learning are challenged. ELL students would most benefit from the middle or average group worksheet as they would neither move too fast or too slowly for a child with limited understanding of scientific terms in English, but can converse fairly well with peers. (See lesson activity description). It could also be given as a take-home activity for independent experimenting. From beginning to end, the class would need no less than 50 minutes. This includes the clean-up and a short wrap-up discussion before worksheets are turned in. The last part of the worksheet (further investigations) could be done in another class period or as a take-home / extra credit assignment. Pre-planning and preparations are necessary to be certain all lab materials are available and students are in predetermined ability groups.

This activity was adapted from "The Solar System and Beyond"; Harcourt Science Harcourt, Inc. 2005 Edition, Grade 5; www.harcourtschool.com

The following is the cover sheet of instructions (attachment #4) each group receives. In addition, the groups will each get the worksheet fit to their group. (See attachments).
***********************************************************************
The Formation of the Moon's Craters - General Information and Procedure

As Earth's nearest neighbor in space, the moon was the first object in the Solar System that people studied. They observed that the moon's surface was very different from the Earth's surface. One difference was the large number of craters on the moon. In this investigation you will make a model of the moon's surface and perform an experiment to infer how the moon's craters were formed. In your experiment you will find out how the height from which a marble is dropped (representing the speed of the object) onto a soft surface affects the size of the impression it makes.

Obtain the following Materials:

3 sheets of newspaper
aluminum pan
small metric ruler
a meter stick
a standard marble
a plastic spoon
container of flour paste
a large marble (optional)
small bag (about 1/4 cup) of additional flour

Do This:

1. Spread the newspaper out to full size; one sheet on top of the other, and place the sheets on the floor. Place the pan in the center of the newspaper.
2. Evenly cover the bottom of the aluminum pan with flour paste and smooth it out evenly. Obtain enough additional dry flour to lightly cover the surface of the mixture in the pan. The flour paste is very gooey; coat the surface well.
3. One team member now holds the meter stick straight up on the surface of the flour paste near the edge of the pan (metric numerals should be facing away from stick holder).
4. Another team member will take the marble and drop it into the flour paste from the 20 cm mark on the meter stick. (To avoid flour in your eyes, do not get too close to the pan as the marble is dropped).
5. Carefully remove the marble and, with the smaller ruler, measure the outer width of the impression in the flour paste. Record your measurements on your Experiment Data sheet. Move the meter stick to a new spot and do steps 4 and 5 two more times. Average the three trials and record the average on your data table.
6. Repeat steps 4 and 5 above using the heights of 40 cm, 80 cm, and 100 cm. If you run out of places to drop the marble, gently smooth out the paste between height changes, add a little more flour to the surface, and then drop the marble.
7. Finish your Experiment Work Page. Confer with your team members only!
   Use your data to answer the questions.
8. Clean up following teacher instructions.

Impact Craters: Differentiated Experiment Worksheet X/High (Microsoft Word 42kB Jun1 11) Impact Craters: Differentiated Experiment Worksheet Y/Middle (Microsoft Word 43kB Jun1 11) Impact Craters: Differentiated Experiment Worksheet Z/Low (Microsoft Word 45kB Jun1 11) Student Instructions for Activity (Microsoft Word 27kB Jun1 11)

1. This flour paste is made from white flour and water. Use a ratio of 1 cup flour to 1/2 cup water. This is an extremely gooey mixture. Try using more flour for a firmer paste. The original directions were to have the kids mix the flour and water right in the pan, but I prefer to do this ahead of time. It is necessary to coat the surface well with flour so the marbles can be easily retrieved. I have not tried it, but a plastic spoon onto which the marble can be rolled may work better than young fingers plucking out the marble and consequently further pushing it into the paste. Also, instead of flour paste, some modeling clay could possibly be used, but I have not tried this.
2. Expansions on this: Demonstrate or have students drop the marble into very watery flour paste and move the pan around simulating weathering on earth. They could also drop the marble into a cup of water showing that no impact craters are left on Earth's ocean surface. Simulating an object's trip through the atmosphere could be done by rolling the marble down a paper tube at different angles, then measuring the impact (could be hard to measure any differences). I have not tried these ideas, but they are mine.
3. I HAVE NOT TRIED THE DIFFERENTIATED APPROACH TO THIS ACTIVITY.
   There could be a lot of different things going on in the classroom at one time and kids are bound to compare worksheets, especially if frustrated. Larger groups may help, but 5 is the upper limit. If not using the differentiated worksheets (Experiment Data Form), I recommend using the middle group (Y) page as it is closest to what I would expect from a 5th grade class.

Students will be graded on their completed Data Experiment worksheets. (See attachments)

5 I B1,2 Grade 5 History and Nature of Science; B - Scientific Inquiry / Performing a Controlled Experiment
5 III. A5 Interaction of Earth and Space