The details about space and the Moon in sentence 8 highlight the great distances a message sent by ham radio can travel.
The main effect of sentence 8's details about space and the Moon is that they highlight the great distances a message sent by ham radio can travel.
The passage mentions that the author has built a life around space, and has worked on a laser system to bounce and detect photons off the reflectors placed on the lunar surface by the Apollo astronauts.
This demonstrates the author's fascination with space and how far-reaching ham radio communications can be.