[0] Introduction: What do we see out there? What we know, what we think and what we are clueless about.
[1] First solved problem: Gravitational few body dynamics and the motion of the planets and the moon. In particular, deriving the 1/r^2 law from observations and resolving the challenges posed by the large precession of the moon (surprisingly large 3-body effect) and mercury (general relativity).
[2] Second solved problem: Structure of Stars and White Dwarfs: How do they work? How do we know? Calculating the main properties roughly (analytically) and accurately (numerically) and comparing to observations.
[3.1] The distance ladder and a little about galaxies.
[3.2] Third (partly) solved problem: The expansion of the universe. What do we know about the "Big Bang" and how? What problems did it solve (e.g. formation of Helium)? What we don't know (e.g. why is the universe expanding??)
[4] Some things we know about neutron stars, black holes and stellar explosions (supernovae). In particular, demonstrating that supernovae contribute significantly to the abundances of elements heavier than helium and therefore are important for our existence.