Use of the word "Prime" in home worlds of various science fiction

I’ve noticed that the word prime shows up in a lot of home-worlds in various science fiction and video games.

Some examples:

Giedi Prime - House Harkonnen from Dune
Centauri Prime - Centauri from Babylon 5
Raxus Prime - Star Wars (not a homeworld though)
Please feel free to come up with more examples of your own. So my question is basically, why do they do this? Who was the first sci-fi or other author to refer to a planet as _____ Prime? Does this naming scheme have any astronomical/astrological meaning or significance?

It’s funny because these worlds often show up in universes where they are the only planet referred to as “Prime” whereas other worlds will just have regular names. I always found that curious as well, however I’m sure it’s not a hard and fast rule.

Basically I’m just curious about the origins, history and usage of the term, and also curious for all the other examples you can think of. Thanks!

It’s from latin, meaning first. Sometimes it’s the closest planet to a star, other times the first to be discovered or colonized (Which is why so many inhabited planets are named Prime.). Similarly, Ix is the ninth planet in its star system, derived from the latin numerals IX.

In a Fredric Brown story they find another planet inside the orbit of what they thought was the first planet of the star Sirius (or, in this thread’s terminology, Sirius Prime).

The name of the planet (and the story)?

Nothing Sirius

e.g. Cardassia Prime- Star Trek- is the Cardassians’ PRIMARY planet; the seat of their Empire.

It is often used to denote Planet of Origin for a Species.

Then, there’s another Meaning, as in: The Prime Directive: the philosophy which informs all of the principles of members of Star Fleet and the Federation of Planets.

Referring to Planets or Edicts, it generally means: The Central or Most Important … Tho Sometimes to First.

And, Prime Numbers- a biggie in Science/Science Fiction.

In the DC universe, “Earth Prime” is the center of the multiverse.

It’s where we (the readers and creators) live.

Then, of course, Jerome Bixby’s other story has an expedition that finds a third moon of Mars, orbiting at an altitude of just a few feet, and the pun-addicted commander of the mission names it…

Bottomos.

Does anyone know of the first use of Prime to refer to an important planet this way? Was it Dune? Is the continued use of Prime in various different sci-fi universes a wink and a nod to the original use of it?

Marvel’s comic book universe has Ego Prime, which is created by breaking off a piece of Ego, the Living (and intelligent and self-aware) Planet. But in that case, the use of “Prime” indicates the tendency physicist and mathematicians have of designating a slightly different version of an original, rather than denoting the first planet.

It was in the 1960s, but I think it post-dated Frank Herbert’s use of Giedi Prime, which is the earliest I can think of.

I think it’s better to use Arabic natural numbers for orbital position. We are on Sol 3.

Discovery order in real astronomy nowadays is indicated with letters, where an (often omitted) “a” is the system primary (the star, or the most-massive star if more than one). Gliese 581g is held to be the sixth discovered planet of the star Gliese 581[a].

Right. Once we have settlements on a few other worlds, we can call this one Sol Prime.

Merry Christmas from Chiron Beta Prime.

And yet, there’s another meaning of prime which means almost the opposite of first:

he he peremensoe… tho i think an argument can be made that earth is likely to be more of an hegemony than an empire… sadly, i doubt we’ll be known as 'The Great Celestial Kibbutz".

earth is oft referred to as ‘terra’ in sci fi, too.

Yeah, but this thread is about sci-fi, not actual astronomical science. As one might infer from the mentions of Dune and Star Wars in the OP.

Sliders called the Earth the original group of sliders started sliding from Earth Prime.

Of course I did also say this: Does this naming scheme have any astronomical/astrological meaning or significance?

But I agree the other discussion is getting away from what I was wondering about.

So it seems pretty likely that Dune was the first sci-fi universe to include a Prime planet. That’s kinda a cool influence to have on the rest of sci-fi if it really was started by Herbert.

Did you read your own cite? “Through the early part of the 20th century, the notation x′ was read as “x prime” not because it was an x followed by a “prime symbol”, but because it was the first in the series that continued with x″ (“x second”) and x‴ (“x third”).”.

Thus my distinction.

Though now that we are discovering worlds in other star systems, I’d expect serious science fiction to be informed by real science.

PS… i always took the Latin "Primus’ to mean First In Importance… not necessarily First as in ‘before second and third’. I see ‘Prime’ in Sci-Fi as RANK, more than a description. { Ordinal numbers tell the order of things in a set—first, second, third, etc. Ordinal numbers do not show quantity. They only show rank or position.}

“I’d expect serious science fiction to be informed by real science.”

Hear Hear. And, Science is often informed by Science Fiction, as well. Particularly in Technical Applications…

As for the First Reference of Prime… i do not know. However, the Naming of Planets, etc. as Prime is likely NOT an Homage, but derived directly from it’s definition. Try a Good Set of Oxford’s English Dictionary for Literary Citations.

Sometimes “Terrans” means residents of this here planet (maybe even including non-humans), sometimes it means the species originating on Terra, wherever they dwell. Will our settler descendants on Mars be “Terrans,” or not? Science fiction has answered both ways.

In Star Trek, Prime means it is the planet in the system closest to the star. Rigel IV is the 4th closest planet to Rigel. Rigel Prime would be the closet.

So in our solar system, Mercury would be Sol Prime and Earth would be Sol III.