-How do you think density affects motion in our universe?
-How do these concepts contribute to formation of our solar system?
-Why are the outer planets gaseous (less dense) than the inner planets?
-Why are there more stars in the nucleus of a galaxy that in the disk?
These are just some questions that I would like you to tackle. Use your own words and explain how these things work together. You can also describe how these concepts (density, structure, and motion) are related in other ways too, but space is our topic of the week.