I have some moss growing in the grass in my back yard. The yard is on the eastern side of the house and has trees on one side. It does get sun during the day until the early afternoon. It has been airrated. The moss is starting to create bald patches in the grass. What can I do to get the grass to fill in again?

Broad leaf weed killer should kill it. Then sweeten up the soil with a little lime. Fertilizer never hurts either. A little red fescue or perenial rye may do better in the part shade. Look for shady area mixes.