Question Sheet: Searching for Alien Life


Before reading:

  1. What do you think “astrobiology” is? 
  2. Describe a desert. 
  3. What is a microhabitat?

During reading:

  1. Why have Wettergreen and his colleagues traveled to the Atacama Desert in Chile? 
  2. Zoë gets its name from a Greek word. What does the Greek word mean? 
  3. Describe Zoë’s cameras. 
  4. How does Zoë distinguish between different minerals and molecules? 
  5. What are conditions like in the Atacama Desert? 
  6. Explain what Wettergreen means when he says, “We are finding that the desert is not uniform.”

After reading:

  1. Why would scientists need to work with a robot like Zoë? 
  2. To survive the harsh conditions of the Atacama Desert, what do you think the scientists need to bring along? 
  3. Why has the team testing its robot in the Atacama Desert set up a Web site? 
  4. What kind of life is Zoë looking for? 
  5. How does a microhabitat work? Besides the desert, where else might such habitats exist? 
  6. Why might life found in a desert be similar to life on Mars?


  1. Compare the terrain of Mars to that of the Atacama Desert. In what ways is the terrain similar and in what ways is it different? What other factors might differ if you were to compare a site on Mars with a desert site on Earth? For information about the terrain of Mars, see 
  2. If you wanted to get to the village of San Pedro, which lies in the heart of the Atacama Desert in Chile, from where you live, how would you do it? Check the Web to figure out what flights and roads you would take to get there. For information on touring the Atacama, see (Ladatco Tours).


  1. Write five journal entries about what life is like working with Zoë in the desert. 
  2. After staring into the night sky looking at stars, write a short poem about how you felt.


Suppose the universe has about 100 billion galaxies, and each galaxy contains an average of 100 billion stars. Perhaps one in a million of these stars has a planet, and of these planets, only one in a million is like Earth. How many Earthlike planets, which could support life, would there be in the universe?