When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Author:Filippenko, Alex. Understanding the Universe an Introduction to Astronomy. 2nd Edition ~ Parts 1-8 (The Great Courses). Title:Understanding the Universe an Introduction to Astronomy. We all like the idea of saving a bit of cash, so when we found out how many good quality used products are out there - we just had to let you know!
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.