First I found a recent picture of Mars from the rover. This was to be used as the background.
Then I found a picture of Starbucks. Using my scissor tool I cut out the Starbucks building and created a mask.
I did the same for a picture of Marvin the Martian
In GIMP I used mask images I made as layer masks for the original Starbucks and Marvin images, did some scaling and placing and got this final result.
