What is astrobiology, and describe the history and development of it as a science.  

Study of the distribution and future of life in the universe

  Support the statement that “Life is a cosmic imperative.”

The laws of physics and chemistry are constant and reproducible under similar conditions. If the conditions on another planet are very similar, and the building blocks are present, life will eventually form.

Support the statement that “Life is NOT a cosmic imperative.”

Our existence if a fluke coming from a highly improbable chance event.

 Discuss the probability that there is a global convergence on the earth bound biochemistry. Is this a universal imperative?  Suggest some other systems.

a.    Different Amino acids

b.    Different Chiratlities

c.    Different RNA or DNA

It’s possible, not a universal imperitive

  What criterion should be used to search for planets that might harbor life?

a.    Water and energy.

   Describe what the Gaia hypothesis is and in what context it was formulated. 

Earth’s biosphere, atmosphere, oceans, and soil are a complex entity influencing each other. It was formulated thinking about how to find simple signatures of life on other planets by mere observation.