Online Discussion assignments for this course will consist of multiple  questions/topics presented via a forum created for each module. You  must create a post of at least 200-words in answer to ONE of the week’s  Discussion questions/topics. Be sure to identify the title of the question when posting.

1. Galaxy stuff:   In the chapters on stars, we learned why we are “star stuff.” Explain  why we are also “galaxy stuff.” Does the fact that the entire galaxy  was involved in bringing forth life on Earth change your perspective on  Earth or on life? If so, how. If not, why not?
    
    
2. Galactic Ecosystem:  We have likened the star-gas-star cycle in our Milky Way to the  ecosystem that sustains life on Earth. Here on our planet, water  molecules cycle from the sea to the sky to the ground and back to the  sea. Our bodies convert atmospheric oxygen molecules into carbon  dioxide, and plants convert carbon dioxide back into oxygen molecules.  How are the cycles of matter on Earth similar to the cycles of matter in  the galaxy? How do they differ? Do you think the term ecosystem is  appropriate in discussions of the galaxy?