41. IS ANYBODY OUT THERE?

from Come Fly With Me – Exploring Science through aviation and aerospace concepts.

SUBJECT: Science
GRADE: 7,8,9
GROUP SIZE: small
TIME: Several Days
TYPE OF ACTIVITY: Student Investigation TEACHING STRATEGY Guided Discovery Discussion
CONCEPTS: Nutrient Medium Extraterrestrial life
SKILLS: Experimentation Interpreting Data Hypothesizing

Objectives: To demonstrate how to collect and grow living things in a nutrient medium; to relate the experiment to scientists searching for life in space.

Materials: Refrigerator jars, plastic butter tubs or covered Petri dishes; bread.
Teacher Background Information: Molds, yeasts, or similar micro-organisms can be found almost anywhere in the world. Any bit of material, whether of air, water, or earth, contains numerous examples of such micro-organisms. Under ideal conditions, they sprout into lush, spectacularly beautiful, microscopic jungles.

This simple form of life offers space scientists a means of investigating the possibility of life on other planets. Scientists believe there is a greater possibility that this type of plant life, or something comparable, would be associated with other living things. Accordingly, they have designed small robot instruments which land on the surface of distant planets and draw some of the surrounding material inside and drop it into a culture medium. Periodically, this liquid food is checked for chemical changes and the container for temperature or atmospheric composition changes. This information is transmitted back to the earth where the biological scientists compare it with already existing knowledge.
Procedure:

A covered refrigerator dish or clean glass jar makes a good environmental area for some types of microorganism growth.

1. Have students obtain a supply of molds by rubbing a piece of bread across a carpet or other floor area. Moisten the bread and put it into a covered environmental area for several days. (Since molds and related plants do not possess chlorophyll, they should flourish without sunlight.)
2. After several days, have the students examine the growth with a low powered microscope or hand lens. Viewing is best with a bright light falling on the surface of the growth. Ask students to notice the rate and types of growth as well as changes in the base materials.
3. Ask students to think of experiments scientists might do in order to determine if life exists on another planet. Why would it be important to determine this? Might there be a need for protection from some microbes in space? Discuss virulent and benign forms of microorganisms.
4. Ask the students what finding microorganisms in space might say about the likelihood of finding more complicated forms of life in space. Relate this experiment to the Voyager experiments and have the students do some research on how the scientists went about looking for life and what they found. Relate this activity to your general study of mycocetes.