Tom Skerritt wears a Casio Dual F100 Watch (custom prop)

Here is a fact that ought to be better known. The most famous wristwatch in the history of science fiction does not exist. It was never manufactured, never sold, never given a model number by the company that supposedly made it. For thirty-five years it did not even have a name.

What it had was two Casio F-100s, joined back to back.

When Ridley Scott shot Alien in 1978, his prop department needed watches for the crew of the Nostromo that looked like the year 2122 and not the year 1978. Their solution was to buy the Casio F-100, a flat resin-cased digital watch that had reached stores in 1977 as Casio's first plastic watch, and double it. Two F-100s went onto a single strap, joined on an orange backing plate, the buttons of one painted red and the buttons of the other blue. The result read, on screen, as a single strange instrument from the future. Tom Skerritt's Captain Dallas wears one. So does Ripley. So do most of the crew, which is how you know it was issued kit and not personal taste.

Dallas is the man the watch is easiest to read onto. He captains a commercial towing ship hauling twenty million tons of ore for a company that has filed its crew under expendable, and Skerritt plays him with the tired competence of someone who suspects as much. He dies in the air ducts, hunting the creature with a flamethrower while the others track him on a scanner. Through all of it the doubled Casio sits on his wrist, a cheap thing made to look advanced, which is a fair description of almost everything aboard the Nostromo.

The strangest chapter came later. In 2014, the video game Alien: Isolation went back into this universe and, needing to label the captain's watch, invented a manufacturer and a model number for it. They called it the Samani E-125. A prop cobbled together from two drugstore Casios in 1978 had finally, retroactively, become a real product in a fictional world, which is the kind of loop only a decades-old franchise bothers to close.