Chapter One

Question 1

What are extra-solar planets?

Answer 1

Planets orbiting stars other than our sun.

Question 2

What are habitable worlds?

Answer 2

Worlds that have the ingredients and conditions necessary for life.

Question 3

What 3 planetary science context assertions support that vast numbers of stars should have habitable planets?

Answer 3

1. Modern understanding of how planets form. 2. Evidence that most stars have planets. 3. Understanding the conditions that make a planet habitable.

Question 4

What 3 biological context assertions support that biology may be common in the universe?

Answer 4

1. Evidence that organic molecules form easily and naturally. 2. Evidence that life appeared early in the history of the Earth. 3. Evidence that Earth life can survive under a wide range of conditions.