My Science Box

Lesson Plan

1. Open the lesson with a description of the Mars Expedition Rover mission. Show students pictures and, if possible, videos of the rovers and the blueberries that were discovered.
2. Pass out the handout and describe the challenge. NASA has given the class samples of “Martian soils” including “crushed blueberries”. It is the job of each team of students to design 3 tests to determine whether any of the soil samples contain something alive or something that once was alive. They must carefully select the “best” group of 3 tests and write down detailed procedures for how they plan to conduct each test.
3. Describe the materials (especially the nutrient milkshake since this is new to the students) and the different tests available for the students to try. You may want to point out that most of the tests students conducted previously were done with liquids, not solid soil samples. Therefore, for SOME tests, students may wish to mix their sample with water (1 part sample to 2 parts water)
4. Answer any questions then distribute soil samples and hand lenses.
5. Get the students started making initial observations and discussing their experimental design in groups. The experiment should roll along from here. Once students have 3 tests designed and written down, they should come to you for approval before conducting the tests. Soon, students will be conducting various experiments and making discoveries. Expect teams to finish at different rates. Some tests, like the agar plate test, may require 24 hours to see results. Expect to spend at least 2 class periods or more on this activity. Encourage teams that finish early to work on the conclusion questions.
6. When all the data has been collected, discuss the results and their conclusions as a class. Compare the results of the different tests and see whether a unified picture emerges. Discuss conflicting results and the reasons they might have appeared.
7. Inform students that the soil samples weren’t actually from Mars. Allow them to discuss what they think was in each sample but don’t reveal the actual ingredients. Many of my students took some of the samples home to further experiment with them and figure out what was in each one.
8. Tell the students what the actual Mars blueberries were found to be – hematite – and why that discovery is important for understanding the history of Mars and the possibility of discovering life on other planets.