The objective for the book cover of "The Martian" was to make it convey the emotion of the or theme of the story. I made three covers to present, each cover aimed at slightly different theme of the story.
The first one uses a potato and a map of mars to create a very Sci-Fi "alien" look even though the book feels like it could be a non-fiction book at times. The audience intended for this cover is definitely science fiction fans.
The Next cover has a bit more of adventure feel to it. It's themed around exploring space but also has a feeling of isolation achieved by a round horizon line and the title being trapped in a bar.
This Book cover is mainly themed around the feeling of Isolation and feeling small. This cover is very minimal with three main elements. There is a stylaized mars in the distance to help make it seem far away and isolated. The title is also kept at a small scale to help keep the book feel quiet, because after all space is a silent vacum. The last element is a stylized morse code message meant to show desperation to make contact. This message is also isolated from other elements of the cover.