astrobiology
Drake equation
habitable zone
organic molecule
SETI
water hole
Discussion Questions
Which stellar spectral type is most likely to have a planet on which advanced life exists?
Which element serves as the foundation or “backbone” of life?
What arguments could you make against sending messages via radio or spacecraft into interstellar space?
Try using the Drake equation with values that you find reasonable. How many civilizations do you estimate there are in our Galaxy?
Discuss the possible biological effects of our probes that visit other life-sustaining worlds.
What social effects might probes from other worlds have on us?
List some of the pros and cons in the argument that alien spacecraft have visited Earth.
What If…
Our planet was the moon of a much larger, Jupiterlike planet that orbits the Sun at 1 AU? What might Earth and life inhabiting it be like?
Our Moon was Earth-sized and also had life on it?
We discover living organisms in Europa’s subsurface oceans? What precautions should we take in the search for such life, and why?
We develop life in a Miller-Urey–like experiment? Explore some of the implications that this event would have.
Web Questions
What information would you have put on the record sent out on the Voyager spacecraft? Compare your answer to the results listed in the Web link associated with that record.
To test your understanding of the Miller-Urey experiment, do Interactive Exercise 19.1 on the assigned Web site. You can print out your answers, if requested.
To test your understanding of the Drake equation, do Interactive Exercise 19.2 on the assigned Web site. You can print out your answers, if requested.
Got It?
Have astronomers found concrete evidence for the existence of extraterrestrial life? If so, please describe these discoveries.
Have scientists found credible evidence that extraterrestrials have visited Earth? Explain your answer.
Has life been created in the laboratory? If so, when and where?