Objectives: Life in the Universe

Chapter Objectives: It is a fascinating question: Are we alone? How do scientists consider the topic of life elsewhere in the Universe without dealing entirely in pure speculation or science fiction? The basic principles underlying the search for extraterrestrial life will be outlined in this chapter. The definition of life and its most fundamental biological components will be discussed. The probability of other solar systems with planets within their habitable zone (ecosphere) will be investigated. The possibility of communicating with an extraterrestrial intelligent civilization will be explored and the criteria used to decide the proper method of communication will be discussed.

Chapter Skills: After studying this chapter you should be able to

  1. Identify the basic characteristics of life as we know it.
  2. Describe briefly the structure of the DNA molecule.
  3. Outline the history of life on Earth.
  4. Discuss the habitable zones (ecospheres) around different types of stars.
  5. Describe different methods that have been used to attempt communication with extraterrestrial civilizations.
  6. Explain why the "water hole" is regarded as the most logical region of the radio spectrum to search for signals from other civilizations.