Answer: Mars

The Spock we know and love today isn’t exactly the Spock that first hit the drawing board back in the early days of Star Trek planning sessions. In his earliest form, Spock was an alien with a metal plate in his stomach that was used to consume energy in place of food. That idea was scrapped rather quickly and the version of Spock we’re more familiar with started to take shape, only instead of hailing from the planet Vulcan, he hailed from Mars.

In what might be the greatest show of optimism ever, Gene Roddenberry vetoed the idea of Spock hailing from Mars based on a singular premise: if humanity landed on Mars before the TV series ended, it would look rather silly that there were no “aliens” there. Instead, Spock was given a completely fictitious home world known as Vulcan.

In fairness to Roddenberry though, while the original series didn’t last long enough to see us put a probe on Mars (firmly establishing that there was no detectable life there, let alone any Spock-like humanoids), Star Trek as an institution certainly did and he was justified in insisting that Spock come from a far-flung planet. Given the enduring popularity of the franchise he created, we have no doubts that Star Trek will still be in the public consciousness when the first humans step out onto Martian soil.