In a follow-up tweet – posted before Romero's response – Petersen acknowledges that Tom Hall did, indeed, craft the original Doom backstory. "And then I did not have access to it when I wrote the ...
As an added bonus, the ESA got OPS-SAT to take an image of the Earth at the same time as it took the screenshot, with the Earth then replacing Martian landscape in Doom's skybox. You can 'watch ...