What Do We Call Martians? 15 Real Demonyms Proposed for Space

Why Space Needs Demonyms: The Martian Question and Beyond

What do we call Martians? The word feels settled — we have said it in pulp novels, mission briefings, and children's questions for more than a century. Yet "Martian" is only one of several proposed demonyms for space, and far from the only one competing for habit.

A demonym is simply the name for the people or things associated with a particular place: Parisian for Paris, Brazilian for Brazil. The pattern is easy to apply on Earth, where borders are surveyed and settled. It gets far more interesting when the places in question have no residents to argue the point.

This article gathers 15 real proposals for extraterrestrial demonyms, drawn from astronomy, science fiction, and the working vocabulary of scientists. They fall into five groups, and each group solves the naming problem in its own way. You will find Latin-derived names for the inner, rocky worlds; Greek alternatives that offer a competing etymological tradition; names for the Moon and for Earth itself, which is the one inhabited place on the list; names drawn from the gas giants; and finally the ice giants alongside Pluto, the case that sparked the most public naming dispute in modern astronomy.

One clarification worth making before we begin: the International Astronomical Union does not officially regulate demonyms for extraterrestrial places. It governs the naming of features and bodies, not what we call the people who might live there. Everything that follows is proposal, convention, and argument — the pleasant kind of uncertainty that leaves room for writers to choose their words carefully.

The Classic Trio: Martian, Venusian, and Mercurian

English has a settled default for the Red Planet: Martian. It is the demonym you will find in dictionaries, newsrooms, and style guides, and it sets the pattern that the rest of the solar system's names tend to follow. Venusian and Mercurian are built the same way—classical root plus the familiar Latin-derived suffix -ian, the same ending that gives us Bostonian or Parisian. The pattern is so productive that writers reach for it almost automatically.

• Martian — root: Mars; pattern: -ian; example: H. G. Wells's invaders in The War of the Worlds (1898) are Martians, and Ray Bradbury returns to the word throughout The Martian Chronicles (1950), where the adjective does the naming work that the noun never quite could.

• Venusian — root: Venus; pattern: -ian; example: Venusians populate a great deal of early science fiction, from pulp magazines of the 1920s and 1930s onward, and the term also turns up in older astronomy writing when authors wanted a personified name for the planet's hypothetical inhabitants.

• Mercurian — root: Mercury; pattern: -ian; example: the same suffix applied to the innermost planet, appearing in early astronomy prose and speculative fiction whenever a writer needed a short, native-sounding label for someone from Mercury.

What links the three is not astronomy but morphology. Each takes the planet's Latin name unchanged, drops on -ian, and produces a word that reads as English on first encounter. That predictability is why Martian became the default English demonym and why its siblings feel immediately plausible, even when the planets themselves turn out to be far less hospitable than the names suggest.

Greek Alternatives: Arean, Cytherean, and Hermian

Arean keeps the war god's own name intact, which is exactly why poets reach for it when they want Mars's violence rather than its astronomy. You will find it in Victorian and Edwardian verse, and it survives in a few scientific adjectives—most notably areic, a term used in planetary science and soil chemistry to describe soils depleted of soluble salts. It never displaced the everyday form, but it carries a harder, older sound than the Latin-derived alternative, and it reappears whenever a writer wants the planet to feel like a character rather than a coordinate.

Cytherean is the most elegant of the three, hinging on Aphrodite's island birth at Cythera rather than on her Roman counterpart. The word shows up in astronomy in the Cytherean atmosphere and in early speculation about conditions on Venus, and it drifts into science fiction whenever a writer wants Venusian romance with a classical tilt. As an adjective it lends Venus a mythological pedigree that "Venusian" states plainly and without poetry.

Hermian is rarest of the three, and mostly confined to older astronomical prose where Hermian describes features and phenomena tied to Mercury. Hermes, the fleet messenger, maps neatly onto the fastest planet, and the demonym appears in periodical literature more than in fiction.

Set beside Section 2's Latin family, the difference is one of inheritance: those forms borrow Roman gods, while these reach further back to Greek originals, trading broad familiarity for a more archaic, literary register.

Moon and Earth: Lunar, Selenian, and Terran

Two of the oldest names in the sky point in opposite directions: one names the Moon by its face, the other by the goddess behind it, and both have travelled back down to Earth.

• Lunar — The standard English adjective for the Moon (lunar eclipse, lunar module) has long doubled as a noun for its inhabitants, which is where the capitalization debate begins. Style guides and science-fiction writers differ: "Lunar" with a capital L treats the word as a proper demonym, while lowercase "lunar" keeps it an ordinary adjective, implying "people who are lunar" rather than a named nationality. Neither side has won outright, so check the house style before you commit.

• Selenian — Drawn from Selene, the Greek goddess who drove her chariot across the night sky, Selenian is the classical counterpart to Lunar. Where Lunar describes the body, Selenian invokes the figure the ancients associated with it. You will find it proposed as a more distinctive alternative, and it does turn up in poetry and older astronomy writing, but it remains a poetic option rather than the everyday choice.

• Terran — Earth's demonym in science fiction and in scientific shorthand alike: starships are crewed by Terrans, and planetary scientists use the term when comparing our world with others. It sits deliberately apart from Earthling, which carries a faintly comic, outsider's-view-of-us ring, and from Tellurian, derived from Tellus, the Roman earth goddess, which you may meet in older English prose as a genteel synonym.

The pattern repeats across the solar system: a Latin or Greek root, a goddess or a physical trait, and a slow negotiation over who gets to capitalize.

Gas Giants: Jovian, Saturnian, and Kronian

Of the outer giants, three demonym proposals carry real currency in print.

1. Jovian — derived from Jupiter, or its alternative Latin name Jove, which is also where we get the adjective "jovial." Jovian is the standard demonym for Jupiter, and it has expanded well beyond the planet itself: the term "Jovian planets" groups the four large gas giants together, a usage you will encounter constantly in astronomy texts. As a modifier, Jovian is a model of stability — it does what a demonym should do, marking both origin and belonging without ambiguity.
2. Saturnian — from Saturn, and here writers must watch their footing. Saturnian names two quite different things: the planet Saturn and its geological period, the Saturnian system of layers and epochs studied in planetary science. A sentence about a Saturnian colony and a sentence about Saturnian stratigraphy are talking about unrelated subjects. Context carries the load, so name the referent explicitly when either reading is possible — "Saturnian atmosphere" leaves little doubt, while bare "Saturnian" can drift.
3. Kronian — from Kronos, the Greek figure the Romans identified with Saturn. This is a Greek-derived alternative to Saturnian, and it appears in some scientific proposals and in poetic writing where the Greek register suits the tone. Kronian has never displaced Saturnian in general use, but it is a legitimate option when you want to evoke classical mythology rather than Roman tradition, or when a passage is already drawing on Greek names.

Each of these three follows the familiar Latin and Greek pattern that governs most planetary demonyms, with the interesting twist that Kronian and Saturnian can describe the same world from two different mythological directions.

Ice Giants and Beyond: Uranian, Neptunian, and Plutonian

Beyond Mars, the outer solar system gives us a small cluster of demonyms that follow the classical pattern almost by the book: a Roman deity's name plus the suffix -an.

• Uranian — formed from Uranus, the Greek-rooted name of the seventh planet (itself derived from Ouranos, the sky). The word carries a complication worth knowing: Uranian has a long independent life as a historical term connected to Aphrodite Urania, the heavenly aspect of the Greek goddess of love, and later adopted in nineteenth-century discussions of desire and gender. Writers working on astronomy should make the planetary referent explicit in context, because the older usage is still encountered in literary and historical texts. When the subject is the pale blue ice giant, Uranian is the correct demonym.
• Neptunian — built on Neptune, the Roman god of the sea, whose name was assigned to the eighth planet. The adjective does steady work in two registers: astronomy, where it describes atmospheric features, magnetic fields, and the planet's many moons, and science fiction, where a Neptunian is any imagined inhabitant of the world. Both uses are well enough established to pass without explanation.
• Plutonian — derived from Pluto, a name chosen in 1930 after the suggestion of an eleven-year-old schoolgirl, following the classical sequence. Pluto's reclassification as a dwarf planet in 2006 means the demonym now describes a body the International Astronomical Union no longer counts among the planets, a distinction careful style guides preserve. The name itself reaches back to the Greek underworld: Plouton, the god of riches and the dead, ruler of the realm beneath the earth.

So, after all these far-flung worlds, the older question still stands: what do we call Martians?