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Searching for Life

Source Institutions

    Lunar and Planetary Institute

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Searching for Life

In this activity, learners discuss how life is defined and conduct a simple experiment, looking for signs of life in three different “soil” samples. The experiment introduces learners to the difficulty that scientists face in defining life. By observing the soil samples, learners try to determine if any contain signs of life and work to identify, refine, and create a set of characteristics that may be used to identify living versus nonliving things. The activity concludes with the development of a group definition of life.

Quick Guide

Preparation Time:
10 to 30 minutes

Learning Time:
45 to 60 minutes

Estimated Materials Cost:
$5 - $10 per group of students

Age Range:
Ages 8 - 14

Resource Types:
Activity, Experiment/Lab Activity, Lesson/Lesson Plan


Materials List (per group of students)

  • 3 (clean) plastic cups (5–8 oz.), clear if available
  • ¾ to 1 cup of sand, enough to fill each cup ¼ full
  • 3 teaspoons (tsp.) sugar
  • 1 teaspoon (tsp.) instant active dry yeast
  • 1 tablet of crushed (as finely as possible) Alka-Seltzer® or comparable fizzing tablets
  • hot water, enough to cover the sand in each cup (not hot enough to kill the yeast)
  • 1 pitcher, carafe, or other appropriate container for the hot water
  • library books related to the topic (optional)
  • a variety of colorful Post-It® notes (optional)
  • Pens or pencils
  • Extreme-O-File: Searching for Life activity pages


  • Earth and Space Science
    • Astronomy
    • Solar System
      • The Planets
  • Life Sciences
    • Cells
      • Cell Metabolism
      • Chemistry of Life
    • Diversity of Life
  • Physical Sciences
    • Chemistry
      • Chemical Reactions
      • Chemistry of Life
    • States of Matter
      • Gases
  • The Nature of Science
    • The Scientific Process
      • The Scientific Worldview
      • About Inquiry
      • Asking Questions
      • Conducting Investigations
      • Gathering Data
      • Formulating Explanations
      • Communicating Results
    • Science as a Career


To use this activity, learners need to:

  • see
  • read
  • touch

Learning styles supported:

  • Involves teamwork and communication skills
  • Involves hands-on or lab activities

Culture, ethnicity, and gender

  • Girls

    • Explicity developed for this group
    • Acknowledges this group's contributions to STEM
    • Highlights STEM opportunities for this group
    • Identifies role models or mentors in STEM fields from this group
    • Uses inclusive images of people from this group


Components that are part of this resource:

Includes alignment to state and/or national standards

This resource is part of:

Access Rights:

  • Free access



  • Lunar and Planetary Institute, 2013

Funding Source:



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