The subject is introductory astronomy but that isn't a choice for me to pick, I have to write another half-page about things on the subject of the inner solar system and a small number of things outside of the solar system. This includes stars, exoplanets, planets, asteroid belts in our solar system, H-R diagrams, etc. I need to expand this to fit the whole page, but I can't think of anything else to expand on other than adding useless details. Any help would be appreciated on how I can expand on the subjects I mention in the essay attatched. Thanks :)