Watching Star Trek: Discovery, I rediscovered the symbol of the Terran Empire of the Mirror Universe: a planet with a sword behind it. That makes me think of the heraldry of H. Beam Piper’s Sword Worlds.
The Nemesis came back to the Gorram yards and settled onto her curved landing legs like a monstrous spider. The Enterprise had borne the Ward sword and atom-symbol; the Nemesis should [page 30] bear his own badge, but the bisonoid head, tawny on green, of Traskon, was no longer his. He chose a skull impaled on an upright sword, and it was blazoned on the ship when he and Harkaman took her out for her shakedown cruise.H. Beam Piper, Space Viking (1963) p. 30 Project Gutenberg
The sword-and-planet symbol was introduced in Star Trek #204 “Mirror, Mirror” in 1968 (Wikipedia). Did the novel influence the artists who designed Star Trek: The Original Series? The timing is right but Beam Piper might have been inspired by someone before him. You can find more of the extraordinary cover art of the 1960s and 1970s on zarthani.net and learn about how ideas flowed between written science fiction, TV shows like Star Trek, and crank theories about ancient astronauts in the YouTube channel for Do Ancient Egyptians Dream of Electric Sheep (warning: YouTube).
(scheduled 11 May 2021)