Research and post with your short but complete answer to each of these questions. Please use your best writing, and explain each answer so that anyone else can follow your reasoning.

Describe in your own words the various components in the Milky Way galaxy, and list the features associated with each component.
Describe how astronomers use Newton’s and Kepler’s laws of gravity to measure the mass distribution (amount of mass versus distance to the center) in our galaxy.
What kind of object is M13, and where is it in the universe?