The Minshara class planet Earth

Vulcan from Orbit, 2154

Vulcan, another M-class planet

Ceti Alpha V, 2156

Ceti Alpha V used to be "barely" class M

Mab-Bu IV - Moon, remastered

A class-M moon of Mab-Bu VI

"Maybe we should've picked one with a little more blue and green on it."

In the Federation standard system of planetary classification, a class M, or Minshara class planet, moon, or planetoid was considered to be suitable for humanoid life. By the mid-24th century, thousands of class M planets had been charted by the Federation. These worlds were the first choice for colonization. Since the early 22nd century, Humanity (and later, the Federation) has been terraforming lifeless worlds such as Mars into class M worlds. Environmental conditions on Federation starships mimicked the class M environment. (TOS: "The Cage"; TNG: "Justice", "Home Soil", "Final Mission"; VOY: "Caretaker")


During the mid-22nd century, Vulcan science used the term Minshara-class for such planets. Vulcans were not able to confirm if a planet was Minshara-class through orbital scans, instead sending down probes to collect the necessary data. (ENT: "Strange New World") In 2151, Starfleet officers were not familiar with the term and Enterprise chose to adopt it. However, by 2154, Starfleet had adopted the term class M. A century later, that term was in general use in Starfleet, even though the term "Earth-type" was also occasionally used.

By the 23rd century, it was theorized that there was a mathematical probability of three million Earth-type planets in the Milky Way Galaxy alone. (TOS: "Balance of Terror")

A planet could fall within the range of the M-class classification. This range was from 1 to 4. The Koinonian homeworld was an example of an M-class type 4 planet. (TNG: "The Bonding", "Clues")

The term was sometimes used to characterize an atmosphere rather than a planet. The standard environment aboard Federation starships was class M. (TNG: "New Ground", "Relics")


  • Surface: The surface of these planets was abundant in water. Under the surface, there were additional sources of water. These worlds were geologically active. (VOY: "Caretaker", "Once Upon a Time", "Dragon's Teeth") Minshara-class planets were sometimes associated with significant quantities of the colors blue and green visible (indicating water and plant life respectively). (ENT: "Twilight")

List of class M worlds Edit


Planetary bodies that were, at last appearance, class M.

Image Name Location Indigenous sentient species Notes
892-IV, remastered 892-IV System 892 892-IV natives Density, atmosphere, and proportion of land to water identical to those of Earth; diameter and layout of continents somewhat different
Akaali homeworld Akaali homeworld 78 light years from Sol Akaali
Alpha Carinae II Alpha Carinae II Canopus, Beta Quadrant Alpha Carinae II natives
Alpha Onias III remastered Alpha Onias III Alpha Onias system, Beta Quadrant
USS Franklin escapes Altamid Altamid Altamid system, Necro Cloud Ancient Ones
Angel One remastered Angel I Near the Romulan Neutral Zone Angel I natives
Ankari homeworld Delta Quadrant Ankari
Archer IV orbit Archer IV 61 Ursae Majoris None
Ba'ku planet Ba'ku Briar Patch, Sector 441, Alpha Quadrant Metaphasic radiation from the rings grants those on the surface immortality
Barradas III, remastered Barradas III Barradas system, Sector 2158, Beta Quadrant
Berengaria VII Berengarius system None
Betazed remastered Betazed Betazoids
Boreth, 2257 Boreth Beta Quadrant
Bringloid V, remastered Bringloid V Bringloid system, Ficus sector Devastated by solar flares in 2365, habitability uncertain
Coppelius Coppelius Ghulion system, Vayt sector
Delphi Ardu, remastered Delphi Ardu IV Delphi Ardu system No indigenous life forms as of 2364
Delta Theta III Delta Theta III Delta Theta III aborigines
Delta Vega Vulcan system Delta Vega 40 Eridani A, Vulcan system, Sector 001, Alpha Quadrant
Dozaria Dozaria Dozaria system "Barely" class M
Draygo IV Draygo IV Cardassian sector
Draylon II Draylon II Near Sefalla Prime
Earth Earth Sol system, Sector 001, Alpha Quadrant Humans, Neanderthals, Voth, and Humpback whales
USS Enterprise orbiting Earth Two, remastered Earth Two Earth Two natives An exact physical duplicate of Earth with a divergent history
Evora homeworld Evora
Ferenginar Ferenginar Alpha Quadrant Ferengi Climate dominated by constant rainfall
Gamma Hromi II remastered Gamma Hromi II Gamma Hromi, Hromi Cluster, Beta Quadrant
Gamma Hydra IV Gamma Hydra IV Gamma Hydra, Gamma Hydra sector
Hanon IV Hanon IV Hanon system, Delta Quadrant Hanonians
Haven remastered Haven Beta Cassius Haven natives
Hemikek IV Hemikek system, Delta Quadrant
Keto-Enol Keto-Enol
Koinonian homeworld, remastered Koinonian homeworld Koinonians and a non-corporeal species Barren, though still class M (type 4), following the Koinonian Wars
Kolarus III Kolarus III Kolarin system, near the Romulan Neutral Zone Kolarans
Kylata II Gamma Quadrant
Lactra VII Lactra VII Lactrans
Lambda Paz Lambda Paz Orbiting Pentarus III, Pentarus system "Barely" class M
M-113 M-113 M-113 creatures
Makull's species homeworld Makull's homeworld Orbiting a red dwarf, Delta Quadrant Makull's species
Mariposa, remastered Mariposa Ficus sector
Neural Neural Neural natives
Nibiru village Nibiru Nibirans Flora is red instead of the typical green
Generic brown planet Ocampa Delta Quadrant Ocampans Though still habitable as of 2371, an artificial disaster millennia ago left it incapable of producing rain
Omicron Theta, remastered Omicron Theta Omicron Theta star system Stripped of life by the Crystalline Entity in 2338, though still class M as late as 2364
SS Santa Maria Orellius Orellius system
Organia Organia Alpha Quadrant Organians (disguised as a pre-warp civilization)
Orias III Orias system
Friendship 1 Otrin's homeworld Grid 310, Delta Quadrant Otrin's species Recovering from nuclear winter as of 2378
Paxan homeworld remastered Paxan homeworld Orbiting a T-Tauri type star in the Ngame Nebula A protoplanet; terraformed by the Paxans prior to 2367
Pentarus II Pentarus system
Pentarus V
PlanetHell Planet Hell Delta Quadrant Atmosphere saturated with trigemic vapors and EM disturbances
Pollux IV, remastered Pollux IV Beta Geminorum system, Alpha Quadrant Greek gods
Hide and Q planet set, remastered "Q's planet" Possibly an illusory world created by Q
Qo'noS in 2257 Qo'noS Qo'noS system, Sector 70, Block 27, Beta Quadrant Klingons
Quarra planet far Quarra Delta Quadrant Quarren
USS Rio Grande approaches Rakhar-Hur'q planet-Bajor Rakhar Rakhari sector, Gamma Quadrant Rakhari
Rakosa V Rakosa V Delta Quadrant Rakosans
Ruah IV Ruah IV None
Rubicun III remastered Rubicun III Rubicun star system, inside a star cluster Edo
Sigma Draconis III Sigma Draconis star system Sigma Draconis III natives
Sigma Draconis IV Sigma Draconis IV natives
Sigma Draconis VI remastered Sigma Draconis VI Sigma Draconis VI natives
Talos IV, The Cage remastered Talos IV Talos system, Talos star group Talosians
Takar, False profits Takarian homeworld Delta Quadrant Takarians
Tarakis planet Tarakis Delta Quadrant
Tarella Tarellians Ravaged by the Tarellian Civil War, habitability uncertain
Tarok Tarok Orbiting a planet in the Delta Quadrant
Tarquin's planet Tarquin's planet Delphic Expanse
Taurus II remastered Taurus II Murasaki 312, three light days away from Makus III Taurus II anthropoids
Terra 10 Terra 10 Cepheus, near Arachna Subject to natural spiroid epsilon waves
Terra Nova planet Terra Nova Less than 20 light years from Sol
Terralysium Terralysium 51,000 light years from Sol, Beta Quadrant
Trialas IV Trialas IV Trialas system, near the Borderland
Vacca VI Vacca VI Vaccan system, Cabral sector
Valakis from space Valakis Valakians and Menk
Valo I Valo I Valo system, on the outskirts of Cardassian space
Valo II Valo II
Valo III
Veridian III Veridian III Veridian system, Beta Quadrant None
Veridian IV Veridian IV Veridian IV natives
Vulcan, 2285 Vulcan 40 Eridani A, Vulcan system, Sector 001, Alpha Quadrant Vulcans
Xahea Xahea Grid 07, Quad 09, Block 3, Sector 1 Xaheans
Xantoras from orbit Xantoras Xantoras
Maquis asteroid, The Maquis I Unnamed asteroid in the Badlands Badlands, Alpha Quadrant
Dark matter nebula planet Unnamed dark matter nebula planet Inside a dark matter nebula, located in or near Cardassian space
USS Rio Grande approaches Rakhar-Hur'q planet-Bajor Unnamed Hur'q Central Museum planet Gamma Quadrant
Mab-Bu IV - Moon, remastered Unnamed moon of Mab-Bu VI Orbiting Mab-Bu VI Constantly swept by ionic cyclones and electromagnetic storms
Allos' species moon Unnamed moon near Allos' homeworld Same star system as Allos' homeworld, orbiting an inward planet, Delta Quadrant Atmosphere extended up more than eleven thousand kilometers from the surface
Maquis planet, The Maquis II Unnamed planet used by the Maquis
Unamed planet orbiting Minos Korva Minos Korva system
Crater, Warhead Unnamed planet in the Delta Quadrant Delta Quadrant
Enterprise leaves orbit of planet Unnamed planet under Organian observation Home to a silicon-based virus, possibly not native to the planet
Unnamed sixth planet of System J-25 System J-25
Rock beasts TAS Unnamed planet inhabited by rock beasts A binary star system None
RomulanMinefield-Planet2152 Unnamed planet annexed by the Romulan Star Empire
Unnamed planet in the Strnad solar system Strnad solar system, inside a stellar cluster
Planet (Memorial) Unnamed planet surveyed by the Delta Flyer in 2376 Delta Quadrant
Planet (Repression) Unnamed "Federation colony" planet Delta Quadrant
Planet (Friendship One) Unnamed planet, a potential new homeworld for Otrin's species 132 light years from Otrin's homeworld, Delta Quadrant
Unnamed planet (Homestead) Unnamed planet, a potential new homeworld for the Talaxians Delta Quadrant
Proposed Vaadwaur homeworld Unnamed planet, a potential new homeworld for the Vaadwaur Orbiting a G-type star in the Delta Quadrant
Delta Flyer crashes on an class-M planet (Once upon a time) Unnamed planetoid where the Delta Flyer crashed in 2375 Delta Quadrant Has a bemonite mantle
Vidiian planetoid, Phage Unnamed Vidiian planetoid Delta Quadrant A rogue planetoid; subterranean caves were class M
Multiple unnamed Terikof belt planetoids Terikof belt, Badlands, Alpha Quadrant
Raven crash site planet and moon Unnamed moon, the USS Raven's crash site Orbiting the fifth planet in a yellow dwarf system, B'omar space, Delta Quadrant
Class M freighter crash planet, remastered Unnamed planet, crash site of a Terellian freighter Influenced by violent plasma storms
Chakotay in Vhnori grave Multiple asteroids in an unnamed planet's ring system Inside the ring system of a class D planet in the Delta Quadrant Class M environment likely transplanted from the Vhnori homeworld via subspace vacuoles
Multiple planets in the Mar Oscura Nebula Mar Oscura Nebula

Former Edit

Planetary bodies that were considered class M before a major change in climate or composition.

Image Name Location Indigenous sentient species Notes
Arret remastered Arret Sargon's species Atmosphere destroyed during a civil war 500,000 years ago
Boraal II Boraal II Boraalans Extinguished by an atmospheric dissipation in 2370
Ceti Alpha V, 2156 Ceti Alpha V Ceti Alpha star system, Sector 25712 Barely class M to begin with; further devastated by an orbital shift after the explosion of Ceti Alpha VI in late-2267 or early-2268
Founders' homeworld, 2371 First Founders' homeworld Omarion Nebula, Gamma Quadrant A rogue planet; destroyed by orbital bombardment during the Battle of the Omarion Nebula in 2371
Sarpeidon Sarpeidon Beta Niobe Sarpeidon natives Destroyed when its sun went supernova in 2269
Vulcan consumed by black hole Vulcan 40 Eridani A, Vulcan system, Sector 001, Alpha Quadrant Vulcans Consumed by an artificial black hole in an alternate 2258

Appendices Edit

Background information Edit

  • The term "class M" was first used in "The Cage" to describe the planet Talos IV. The variant "M class" was also often used. The term has become Star Trek shorthand for Earth-like, and due to obvious production practicalities, this environment is the "default" for planetary surface scenes. It should be noted, however, that not all "Earth-like" planets are necessarily class M: class L worlds such as Kelis' homeworld (VOY: "Muse") and even the occasional class D (such as the one seen in VOY: "Gravity") can support life as well.
  • The Vulcan term "Minshara-class" (first used in ENT: "Strange New World") was used in Enterprise to denote planets that in other series would have been called class M by the writers, the implied consequence being that the two terms meant the same, and possibly even that M stood for Minshara. This assumption is supported by the reference book Star Trek: Star Charts. From an in-universe standpoint, the term M-class was first seen chronologically in a text within the Handbook of Exobiology in ENT: "Strange New World", the same episode that introduced Minshara-class. However, this mention was barely legible on-screen and may have been included by an art department not yet aware of the intention to use "Minshara class". The first spoken use of the word was in "Home", in which Archer used it to describe Archer IV, a planet implied (but not explicitly confirmed) to be Minshara class in "Strange New World". The term continued to be used several more times in the final season, while "Minshara-class" made no more appearances. The last use of "Minshara class" was in season three's "Twilight", where it was still used in 2156 in an alternate timeline. The term also appeared on Enterprise's computer displays, indicating that Starfleet adapted it eventually.
  • In TOS: "Return to Tomorrow", Spock called planet Arret class M despite the atmosphere having been ripped away, suggesting that the class M designation goes beyond being able to support life. Alternately, he could have been saying that the planet, prior to losing its atmosphere, would have been categorized as class M.
  • Ceti Alpha V was described as "barely Minshara class" in "Twilight", but also as no more inhospitable and savage then the site of Australia's Botany Bay colony before colonization in "Space Seed", suggesting that even on a class M planet like Earth, there might be locations that stretch the definition. Alternatively, the planet might have become more hospitable in the century between the two episodes.
  • According to Star Trek: Star Charts, class M planets have ages that range from 3 billion to 10 billion years and a diameter between 10,000 and 15,000 kilometers. They are located within the ecosphere of a star system.

Apocrypha Edit

The novel Strangers from the Sky indicates that the term "class M" was used by Humans prior to First Contact with Vulcans, or indeed before Humanity reached any extra-solar planets.

See also Edit

External link Edit

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