What Changed When Andy Weir's The Martian Got Edited?

The Martian is a best-selling science fiction novel by Andy Weir that became a hit film in 2015. The novel exists in two versions, or variants: Weir self-published The Martian on his personal website in 2011 (hereafter, “Martian1”) and began selling it on Amazon.com in 2012. Crown Publishing subsequently bought the rights, edited the book, and re-released it (hereafter, “Martian2”). The research presented here investigates what exactly changed when The Martian got edited. At first glance, the two versions appear essentially the same, with no major changes to plot, character, or structure. A closer look using a combination of quantitative and qualitative methods, however, reveals a number of noteworthy changes, as well as notable changes that result from thousands of seemingly minor copyedits.