Mars for Earthlings > Lesson Modules > In-Class Activity 1- Miller-Urey Experiment

Miller-Urey Experiment

In-Class Activity 1_Origin of Life

Julia Kahmann-Robinson PhD and Marjorie Chan PhD, University of Utah Department of Geology & Geophysics


Have an Internet connection to view the associated video and websites.


Questions for students:

  1. In your own words, define "life":
  2. List four requirements of life:


  1. Students can debate the different definitions of life. A general definition of life is as follows: an organismic state characterized by capacity for metabolism, growth, reaction to stimuli, and reproduction.
  2. Requirements for life are: chemical building blocks, energy, and a liquid medium.
  3. Most researchers would general agree that life requires water; hence NASA's campaign "Follow the Water".
  4. Energy need not be sourced from photosynthesis, rather chemosynthesis for example.


View the following YouTube animation of the Miller-Urey Experiment:

  1. Describe at least (4) conditions of the experiment.
  2. What was "applied" after the gases travelled through the horizontal tube?
  3. Was O2 a gas applied to this experiment? Why or Why not?
  4. Do you think that the Miller-Urey experiment was a good experiment? Do you feel that the researchers set up the conditions of early Earth properly?


  1. Would the Miller-Urey experiment be applicable to Mars?
  2. How would you modify the experiment, if at all, to represent what might have occurred on Mars?
  3. Visit NASA's NAI-Astrobiology website: and explore the various "headlines". List at least (2) ongoing investigations that are applicable to researching the "origin of life"
  4. Read "About NAI" on NASA's above website. Are investigations into the origin of life a NAI focus? Why or why not?

Students could also consider exploring a planet in a habitable zone and compare it to Earth and Mars, using data from the Kepler mission (See Missions Outside our Solar System Module).


  1. When students consider the present and/or past environment of Mars, do they feel all the requirements for life can be found?
  2. When discussing the origin of life, what is meant by "chemical building blocks"?