1. What two planets are evening or morning “stars”? 2. Why is Earth called “the blue planet”? 3. What gas makes up most of the Martian atmosphere? 4. What evidence tells us that Mars was at one time...

1. What two planets are evening or morning “stars”?

2. Why is Earth called “the blue planet”?

3. What gas makes up most of the Martian atmosphere?

4. What evidence tells us that Mars was at one time wetter than it presently is?