Below is the pdf of the textbook – look at chapter 7 and chapter 8. Here is the

Below is the pdf of the textbook – look at chapter 7 and chapter 8. Here is the link in case it does not work – https://assets.openstax.org/oscms-prodcms/media/documents/Astronomy_2e-WEB.pdf?_gl=1*ovfvpa*_gcl_au*NTI4MDcwOTA1LjE3MjQ2MjIyODc.*_ga*NDA2Njk4Mjg5LjE3MTM5NjE1NTk.*_ga_T746F8B0QC*MTcyNjQ1MjI2NS44LjAuMTcyNjQ1MjI3Mi41My4wLjA. | You need to create three discussion posts. Instructions are in the format document. I also included an example in another document for reference – you don’t need to include sources. It should be more than 150 words per discussion as well. Thank you!