Teacher’s Questions for Germy Clouds


Before reading:

1. If microbes live underground and underwater, do you think they also live above us, in the air? Why or why not?

During reading:

1. Explain how Donald Barber’s images became flecked with germs.

2. Was Barber’s theory about where the germs came from correct? Where, in fact, were the germs coming from, and how were they transported?

3. Describe how Kimberly Prather’s onboard air-testing device works. Name three kinds of particles it commonly detects while sucking in air from clouds.

4. How far have some of the particles detected by Prather traveled?

5. Describe two ways other than winds that germs are transported into the air.

6. Explain how a bursting bubble flings germs into the air.

7. About how many bubbles burst each day in the world’s oceans? And about how many germs are flung into the air each day by this action?

8. What do the peaks on Prather’s computer screen represent? In particular, what type of “ingredients” tell her something living was just zapped?

9. How does Gary Franc identify the type of bacteria present in sampled clouds?

10. How does Erwinia carotovora wreak havoc on potato fields in Idaho? Be sure to explain how the bacteria move from the ocean to the air, and back down to the surface.

11. Explain how germs can make it rain, hail or snow.

12. What is a nucleator? Give a few examples of nucleators.

13. How high up in the atmosphere has Brent Christner collected living bacteria?

14. Name two reasons why it would be tough for anything to live as high up as 30 kilometers.

After reading:

1. Scientists have only recently begun to study life in the air. Were you surprised to read that germs live in the air? Can you think of other places that might host life that scientists haven’t yet explored?

2. Can you think of a few ways that scientists studying atmospheric bacteria could safeguard against accidental contamination?


1. What can bacteria living high in the air tell us about life on the ground, where we live? What can atmospheric bacteria tell us about life on other planets?