What if the solar system passed through a cloud of gas and dust that was beginning to collapse to form a new star and planet system? What might happen to Earth, and how would the passage affect the appearance of the sky?
1. The Earth has had three distinct (evolutionary) atmospheres over its life to date. Describe the composition of these atmospheres and when they occurred.
2. What is the source of the magnetic field that we have on Earth?
3. Why are there so few craters on the maria?
4. What is a star’s habitable zone?
5. What created most of the craters in the Solar System? What else could create craters? (Hint: Think about craters on bodies such as Earth and Venus.)