Fry: I'm impressed. In my time we had no idea Mars had a university.A Speculative Fiction staple, the act of turning an otherwise human-unfriendly environment into an Earth-like, or "Terra-formed" planet. Narratively, this is done to give the cast a place to go outside the ship (off Earth) that won't require them dressing in Space Clothes constantly. Within a given setting, it's often done to showcase humanity's drive to explore and colonize new places for the famed trifecta of God, Gold and Glory. (Hey, at least one setting actively proselytizes, at gunpoint!) Often used to explain why All Planets Are Earth-Like. Terraforming itself is an actual area of study right now, as scientists try to design methods to create both self-contained environments (Bio-Domes being famous examples) and species that can survive in a hostile environment and improve it until it has a self-sustaining biosphere that can sustain humans. Easier said than done. Literally, because soft sci-fi settings tend to sneeze out terraforming efforts and planets like Martians with a cold. Harder scifi settings can construct entire books about the sciences and engineering involved, not to mention the political and social effort these huge undertakings would entail. We would also like to draw your attention to a little bit of verbal trickery in the first sentence: "human-unfriendly environment". This is not the same as uninhabitable, with acid rains, lead-melting temperatures, or hard vacuum. Sometimes, a planet is plenty alive... sometimes, too alive, with man-eating plants, semi- to hyper-evolved sentients, and scores of other dangers. A few old sci-fi serials and pulps would have their heroes' effort designed to create a "domestication" of savage planets, much like The American West was "tamed" with all the attendant heartache and extinctions. More recently, some shows turn this around by showcasing how terraforming an already-living world can be ecologically disastrous, or ethically questionable, even weaponized. Or just plain pisses off the near omnipotent residents. Some works even turn the concept inside-out, showing how aliens arrive on Earth and mess the ecology up so badly that the planet becomes barely habitable, if at all, for humans (any similarities to Global Warming are entirely coincidental); this is sometimes termed xenoforming or un-terraforming. Still less scrupulous beings will weaponize the terraforming process itself; see Hostile Terraforming for more details on that twist. As seen in the trope picture, Mars is likely to be a popular target for any terraforming operation in both fiction and reality. It has one of the shortest travel distances (second only to Venus), and is solid. Venus is also a popular candidate in fiction, being almost completely similar to Earth in terms of size and gravity, but it's second to Mars because warming something up is a lot easier than cooling it down, and unlike Mars, Venus's slow rotation would have to be dealt with. Compare the Genesis Effect, for when an entire planet is actually created instead of just made livable.
Professor Farnsworth: That's because then Mars was a uninhabitable wasteland, much like Utah. But unlike Utah, Mars was eventually made livable when the university was founded in 2636.
Leela: They planted traditional college foliage. Ivy... trees... hemp... soon the whole planet was terraformed!
Professor Farnsworth: That's because then Mars was a uninhabitable wasteland, much like Utah. But unlike Utah, Mars was eventually made livable when the university was founded in 2636.
Leela: They planted traditional college foliage. Ivy... trees... hemp... soon the whole planet was terraformed!
—Futurama, "Mars University"'
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Anime and Manga
- Cowboy Bebop has numerous terraformed planets, moons and asteroids; it appears only small sections of Mars that are protected by some sort of force-field dome are livable, though on Venus the plants used to terraform could cause some people to develop "Venus Sickness" with such side effects as going blind. Ganymede is completely covered in ocean, while Titan is all desert.
- Not force fields, air curtains.
- Terraforming has become a necessity since inversely, Earth has become almost uninhabitable due to the moon getting destroyed and debris bombardment that continues.
- ARIA takes place on Mars, which got mostly covered with water from the pole regions after terraforming and subsequently got renamed to Aqua.
- Zone of the Enders also features a partially-terraformed Mars. in Dolores, i, it's shown that some of the planet's oxygen supply is being generated by seaweed that has grown huge in the new environment, with fronds hundreds of feet long. You still don't wanna go out there for long without a spacesuit.
- It's in progress on Mars as of the first Armitage III OVA. In the epilogue to the sequel, it gets oceans courtesy of a lot of dropped comets.
- In Martian Successor Nadesico, Mars is terraformed through the use of Nanomachines. How these machines affected native Martians becomes a major plot point later on.
- The beginning of an attempt to terraform Mars is mentioned in the finale of Gundam Wing. The sequel novel Frozen Teardrop has it completed roughly 20-30 years later thanks to an accident involving algae from Jupiter's moon Europa (previously studied but deemed too impractical).
- Gundam AGE makes this central to the backstory. Around a hundred years prior to the series, a serious attempt at terraforming Mars was made. An unexpected and extremely deadly plague made the Federation give up, in the process abandoning the settlers already there because they expected them to die out pretty quickly anyway, and sweeping the whole matter under the rug. A few colonists survived though, and formed a nation called Veigan... which is now attacking the Earth Sphere for revenge and is known to them only as the "Unknown Enemy", or UE.
- Osamu Tezuka's Mazin Garon is a Humongous Mecha with the ability to alter planets to mimic the conditions of any other planet, even going so far as to be able to control gravity.
- Near the end of Getter Robo Go, Shin Getter Robo instantly terraforms Mars with a blast of Getter Energy. It does this so it can hibernate on the planet long enough to combine with it and become an even larger robot.
- The world-settlers in Trigun set out to terraform a new planet, but unfortunately ended up crashing onto a desert world (losing much of their tools and resources in the process) and what resources they still have are almost solely devoted to surviving. Due to this, the work has barely even started at the time of the series, and it's implied they'd already been there for several decades or more.
- Almost all populated planets in Kiddy Grade became inhabitable through terraforming. One episode even has Ã‰clair and Lumi Ã$re scavenge terraforming-equipment for usable parts.
- Mars Daybreak features a Mars where terraforming has Gone Horribly Wrong, somehow flooding the entire planet except for the peak of Olympus Mons.
- The bad guys in Space Carrier Blue Noah want to terriform the planet Godom for their own needs.
- In Mahou Sensei Negima!, Negi's plan to save Mundus Magicus is revealed to be terraforming Mars so that it can support life.
- Supplementary materials for Neon Genesis Evangelion reveal that Adam and Lilith are actually alien terraforming biotechnology called Eggs meant to seed life on worlds. The problems on Earth are the result of Adam and Lilith landing on the planet — planets are only supposed to get one of the "Eggs". Fortunately, the Eggs' creators included control rods (the Lances of Longinus) with each Egg that automatically seal them if another Egg had already landed. This is what happened to Adam since Lilith landed on Earth first. Unfortunately, curious humans removed Adam's Lance, kicking off the series.
- In the Wildstorm universe, it's eventually revealed that Earth was in fact terraformed by technology created by the ancestors of the Kherubim, who were far more Sufficiently Advanced than even the present-day Kherans were aware. This explains in part why humans and Kherans can interbreed; our DNA is partially based on theirs.
- But in The Authority, another Wildstorm series, a totally different explanation was given at the end of Warren Ellis's run (not surprisingly, since it's Warren "What Do You Mean, It Wasn't Made on Drugs?" Ellis). Here the Earth was placed in its proper orbit by what is, essentially, God: a pyramidal being the size of our moon with four thousand hearts and pores the size of Staten Island. God even placed some "watch spores" on the planet to make sure everything stayed perfect, then went off to wander the universe for a bit. In the meantime, a big chunk of something hit the Earth, then started orbiting, becoming our moon. By sheer chance, the watch spores were among the matter blown off by the impact. This tilted Earth's axis, altered the atmosphere, and eventually led to the development of life as we know it today. God eventually comes back to discover that its vacation home has suddenly developed a totally poisonous (to it) atmosphere and grown a six-billion-strong infestation. In order to return the planet to its "proper" state, God drops some disgusting organic machinery into the African veldt that begins restoring the original atmosphere. So it's not so much terraforming as un-terraforming.
- The Engineer even tries to come up with a term for it:
Engineer: What would you call that? Un-terraforming? Monsterforming? Disgusting stuff. Turdscaping.
- The Engineer even tries to come up with a term for it:
- In Buck Godot: Zap Gun for Hire, the Prime Mover (a Sufficiently Advanced Alien and Obstructive Bureaucrat) is Terraforming a planet as a hobby, in his room, by hand.
- In his defense though, he did have a really big bucket.
- Some of the Transformers comics written by Simon Furman have a variation of this: In the distant past, the war between alien gods Primus and Unicron was ended when Primus tricked them into eternal imprisonment in large metal planetoids. Over time, Primus terraforms his planetoid into the planet Cybertron (and creates sentient robotic life forms in the process), while Unicron terraforms his into a giant Transforming Mecha body.
Films — Animated
- Titan A.E. had the Titan, which could completely and quickly remake a planet, just like the Genesis Device. Unlike the Genesis Device, though, the planet didn't collapse back on itself after a year note . The Titan didn't so much remake a planet, as make a whole new planet using a local nebula for raw materials. They just happened to call it "New Earth". Besides, we all know it's really called Planet Bob.
Films — Live-Action
- In 2010: The Year We Make Contact, this is revealed to be the aliens' plan for Europa. The Stinger shows that they have succeeded.
- Aliens shows that Weyland-Yutani has terraformed the unihabited planet from the first movie sufficiently for a breatheable atmosphere in the past 57 years. The aliens have holed up in a massive atmosphere generation tower, with an unstable fusion reactor.
- In Red Planet, minimal terraforming efforts had been made to give Mars a breathable atmosphere. However, something went really, really wrong...
- The original Total Recall (1990) does this to Mars, supposedly by rapidly melting the planet's icy core to flood the atmosphere with oxygen. All at once, with no harmful side effects to billions of tons of air suddenly blasting on to the surface faster than any tornado. A window gets broken, that's it. There's not even any dust kicked up. On Mars.
- The Genesis Device from Star Trek II: The Wrath of Khan turns a nebula into an Earthlike planet. Sadly, the planet tore itself apart within a year. If it had been used on a rocky planet instead of a nebula, the planet probably wouldn't have fallen apart if that terraformed underground location Khan imprisoned Kirk and co. in was any indication.
- In Star Trek III, David Marcus admitted that he had used "Proto-matter" (a highly-unstable element) in the design of the Genesis device. Even if Genesis had been aimed at a rocky planet, it would have fallen apart.
- While the film never gave the fate of the test cavern inside the asteroid by Regula 1, the novelization of the film has David and Saavik revisiting the little world and discovering that the little world, too, doesn't seem right, a Foreshadowing of the Genesis World's fate.
- Although it's not seen on-screen, the dialogue in Star Trek: First Contact suggests that the Moon has been at least partly terraformed by the Next Generation era. When Riker, a Fish out of Temporal Water, stands in awe at the sight of the 21st century Moon and Zefram Cochrane rolls his eyes and sarcastically asks whether they still have a Moon in the future, Riker answers that it simply looks "a lot different": in the 24th century, "Lake Armstrong" and several lunar cities are visible from Earth. This does contrast a few earlier episodes, where the 24th century moon put in an appearance and looked the same as ever.
- It may just be possible that he was referring to it being colonized, not terraformed.
- An inversion in The Arrival. An astronomer discovers that a worldwide rise in carbon dioxide levels and resulting global warming is due to aliens seeking to kill off humanity and make Earth more like their planet.
- One of the aliens remarks that humans don't deserve Earth. We're already killing ourselves off, they're merely speeding up the process.
- Possibly occuring to parts of Mexico and the US in Monsters. Trees in the "Infected Zone" are being used to host alien spores.
- Jack Williamson:
- Actually coined the term in a 1942 novella called "Collision Orbit," which can be considered the Trope Namer.
- A later Williamson book, Terraforming Earth, involves Earth itself being terraformed. Not once, but several times, due to asteroid impacts, alien invasions, runaway technology, etc...
- Kim Stanley Robinson's Red Mars Trilogy is the definitive hard sci-fi account of terraforming, going into exhaustive detail about Martian terraforming. He portrays a process that runs for more two hundred years over the course of the three novels, which themselves are named in allusion to key steps in the terraforming project (Red Mars, Green Mars, Blue Mars). One of the ongoing themes of the series is the increasing conflict between the Reds, who want to maintain the pristine beauty of Mars, and the Greens, who want a second Earth. The novels strongly imply that neither outcome is possible; Mars will change the terraformers just as they change it. In the final installment (Blue Mars), we see humans expand out to live on the moons of the gas giants, and inward to establish a constantly-moving city on Mercury.
- The standalone novel 2312 by Kim Stanley Robinson picks up a hundred years after the final installment of the Mars Trilogy, showing humans living throughout the solar system (the main character is a native of Mercury). A minor (but crucial) plotline deals with the terraforming of the planet Venus, which brings its own subtle conflict; do you rush the job, sealing up the remnants of the thick atmosphere under tonnes of rock and using a sunshade to give you artificial days and nights, or do you use the mass of the former atmosphere to spin the planet up - a project that will take far longer, but leave a far more sustainable end result? In the process of terraforming, Robinson's solar system has become an endless playground for sci-fi tropes - giant robots scooping up frozen carbon dioxide on Venus, 'hanging ships' floating in the clouds of Saturn and fully-tented moons that physically hold their atmospheres in.
- In Olaf Stapleton's Last and First Men the Fifth Men begin terraforming Venus when the Moon starts falling towards Earth. Pre-terraforming Venus is apparently an ocean under the cloud cover inhabited by various creatures that feed on radioactive materials, unfortunately oxygen is extremely toxic to them and the Fifth Men don't realize that some of Venus's native life is sentient until they've already started the oxygen enriching chain reactions so they just keep on going. Three more incarnations of Man evolve on Venus before the sun expands and the Eighth Men migrate to Neptune.
- H.G Wells' The War of the Worlds inverts this; the Martians try to areoform the Earth as part of their invasion plan. (Its publication date of 1898 makes this possibly the Ur Example of xenoforming.)
- Another reverse-example is David Gerrold's The War Against the Chtorr novels. Alien creatures are transplanted from their home planet to the Earth to replace our entire ecology.
- In John Christopher's The Tripods (which may well be an Alternate Universe sequel to The War of the Worlds), anti-Terraforming is on the Tripods' agenda somewhere after Enslave Humanity. The alien Masters plan to replace the Earth's atmosphere with one like that of their own planet.
- Isaac Asimov's short story, "Founding Fathers," where a crew of multi-national astronauts crash-lands on an uncharted planet with just enough ammonia in the atmosphere to be unsuitable for human life. There are live plants on the ship, though, and if they can be coaxed to thrive somehow, a tipping point could be reached where the extra oxygen would wipe out the ammonia in a cascade. This is eventually done after a considerable time by burying the deceased humans in the crew into the soil. It is noted that the person who does this will not live to see the transformation finish (the ship's water supply got contaminated), and when this planet is discovered again, there would be no sign that there had ever been ammonia in the atmosphere...
- In one of Philip K Dick's stories, Earth and Titan were in an uneasy peace because of a war that was held because humans terraformed Mars. There were already people of Titan on Mars, but they couldn't breathe oxygen. By the time the humans learned of the Titanians, the terraforming had already begun, and "you can't terraform just part of an atmosphere..."
- Many of the planets in Lois McMaster Bujold's Vorkosigan Saga have to be terraformed to a greater note or lesser note extent.
- In Larry Niven's Known Space universe, most life-bearing planets were seeded with life by the Slavers; not to terraform, but simply to grow enough food for their vast and inefficiently-run empire. Specifically most planets only had a strain of yeast their prey animals enjoyed eating. When the Slavers War ends with the Suicide Night that kills all life on the level of lobsters and higher in the entire Galaxy, the majority of life evolves comes from their yeast farms, which explains why we are biochemically compatible.
- The results of unfinished or untended Terraforming is a large feature in Niven's work. Earth was partly Terraformed by the Pak, with the issue there's not enough thallium for the Pak's final lifestage to complete. Ringworld has much of the same issue being explored with humanoids left alone on a mostly terraformed Ringworld until they differentiate into ecological niches.
- In Niven's A World Out Of Time, delivering biological terraforming packages to suitable extrasolar planets is the job given to the corpsicle Corbell.
- Done accidentally on the planet Canyon. Originally it was a Mars-like kzinti garrison world, with a very thin atmosphere and hydrosphere. During the Third Man-Kzin war, the humans hit it with the Wunderland Treatymaker, gouging out a giant canyon twelve miles deep and two hundred miles long. All the air and water drained into the canyon, creating a perfect living environment (people live on the canyon walls and central ridge, since the floor of the canyon is flooded).
- In the CoDominium universe, New Caledonia is a formerly barren world still being terraformed; for already life-bearing planets, the process is more a matter of altering the local ecology to support Earth life (which is usually grossly simplified for story purposes).
- Riverworld is set on a planet terraformed into one big twisting river valley, to maximize the surface area ideal for human habitation.
- The Robert A. Heinlein story Farmer in the Sky is about a terraforming effort... on Ganymede.
- Dan Simmons' Hyperion Cantos universe has in its backstory humanity terraforming all their worlds, regularly committing genocide against sentient indigenous species. This bothers pretty much no one, human, AI, or transhuman.
- The major theme of Dune is the back-and-forth attempts by humanity to terraform the desert planet Arrakis inhabited by the various life-cycle stages of sandworms (which create an extremely necessary commodity) and by the (non-sentient) sandtrout phase of the worm species to counter terraform Arrakis (and later other worlds) back into desert.
- Honor Harrington has a major factor in the economics of the various colonies being how well they were terraformed. This is largely a function of when you left Earth and how much money you had when leaving. Haven and Manticore were settled fairly late with good resources. Other planets like Grayson were settled by cold sleepers who left very very early, had poor terraforming technology, and ended up on a planet full of heavy metal poisoning.
- The state of the terraforming efforts combined with the cultural base also give planets such as the Albino Zulus whose gene engineered solution to a poor Ozone.
- In Manticore's case it's stated that the only terraforming that was needed was the introduction of a few Terran plants, and that the unusual compatibility of the native life allowed a hybrid plague to develop.
- And it's probably no coincidence that the most populous planet in the Manticore system is the one that doesn't have high gravity or turbulent storms.
- The Magratheans seem worthy of a mention, taking this idea to its logical extreme by creating a custom planet-building business.
- A. E. van Vogt's The Voyage of the Space Beagle: Anabis, a galaxy-spanning consciousness that has terraformed all planets in its own galaxy by ripping a piece of its planets surface off and sending to to the target planet through hyperspace (called junglescaping).
- Like the Magratheans two entries above, Roger Zelazny's character Frank Sandow in Isle of the Dead and To Die in Italbar made a business of building planets, to order, or to his own design. Near the end of the first book, he has a vision of every planet he's built. After seventeen names, it trails off with "and so on." (He's over twelve centuries old; he's had time.)
- In Robert Charles Wilson's Spin, when the Earth is placed under a membrane that slows down time (which means that for the people of Earth the Sun will expand in a few decades), humans successfully terraform Mars; a whole civilisation appears there within a few years (for those on Earth)/a few millennia (for the people of Mars - humans who have evolved slightly differently.)
- The major plot element of the New Jedi Order. Picture a cross between Super Saiyajin and species 8472.
- Cthulhu's Reign, edited by Darrell Schweitzer, is a Cthulhu Mythos anthology of short stories on what
lifeexistence on Earth would be like ifwhen the Old Ones return. There are several references to the Eldritch Abominations 'terra-deforming' the Earth so it's more suited to themselves.
- In one Arthur C. Clarke novel Mars is being terraformed by selection and spread of oxygen-generating plants native to Mars, as well as by turning Deimos into a coninuous thermonuclear explosion, effectively providing the planet more sunlight than the Earth gets for a hundred years.
- In Helm, Epsilon Erdani II — known to its settlers as Agatsu.
- In part three of Alexander Kazantsev's Destruction of Faena, Mars' surface is made inhabitable by bombarding it with rockets made of ice, which melts, creating the first ocean.
- Savior by Robert Reed - A rapidly failing alien starship uses a massive laser cannon to melt the ice bergs to try and make the Earth habitable for them. Naturally, this doesn't go to well for the aliens.
- The Forgotten Planet by Murray Leinster is about a planet that was partially seeded and then lost in the galactic bureaucracy. Microbes and insects were seeded but not vertebrates resulting in a planet of giant insects.
- The Venus Prime novel The Shining Ones involves the protagonists traveling through a black hole into distant past and witnessing a race of squid-like aliens attempting to remake Venus based on a very specific template. They redirect comets to crash on Venus and create water. Unfortunately, they fail to ancitipcate a meteor storm that destroys their efforts. The settlers then split based on their opinion towards the official doctrine, which states that settled planets must be exactly like their homeworld. The rebels end up joining the humans and traveling to Mars to terraform it. One of they ways they do that is by inserting artificial spinning black holes (in containment, of course) into the poles in order to increase gravity to Earth-norm. In the end, though, the loyalists end up attacking Mars and destroying their efforts, returning the planet into the desolate rock we know. The rebels settle for traveling to Earth and lying dormant in the oceanic depths for human life to emerge.
- In one of the earlier books in the series, Sparta muses that at the same time that humans are trying to make Venus more like Earth, Earth is becoming more like Venus, thanks to extensive use of coal power, coupled with humans' over-reliance on air-conditioning.
- In Aristoi, terraforming is so easy that humanity's spread through the cosmos is limited only by the Aristoi not wishing to have to run any more planets.
- In SA Swann's Terran Confederacy universe, the Dolbrians terraformed a number of worlds before vanishing, including Mars. Humans reterraformed Mars, and also terraformed Titan and several other large moons of the outer planets. Those colonies were later destroyed in a Grey Goo incident and the reactions to same.
- In the Paradox Trilogy, Hyrek gives a wry commentary on the various types of terraforming performed by different governments. Paradox uses robots to terrform planets for colonization, blithely wiping out all indigenous species. The Terran Republic, by contrast, takes great care to catalog all native life on potential colony worlds... then wipes it all out in order to transplant human-friendly organisms.
Live Action TV
- Andromeda has the Pyreans, aliens who exist on planets like Venus — super hot, toxic, and deadly to most organic life. They "pyroform" planets by burning them to their tastes, the old Commonwealth had to seriously fight them not to lose precious human habitable worlds.
- In Babylon 5, humanity is in the first stages of terraforming Mars.
- The Cosmos: A Personal Voyage episode "Blues for a Red Planet" discussed the possibility of terraforming Mars with dark-colored, hardy plants.
- Doctor Who
- In the episode "The Doctor's Daughter", the planet Messaline is turned from a desolate wasteland into a beautiful planet full of life by using a terraforming device.
- In Terror of the Zygons, the Zygons planned to modify the Earth’s climate to make it more suitable for their species.
- The Ice Warriors tried the same thing in The Seeds of Death.
- Firefly, where every planet and moon in the system is terraformed. The terraforming is mainly done by massive machines brought from Earth That Was, but human labor is still needed and it's hard, dangerous work.
- Plus, terraforming often has unintended side effects, like the newly introduced atmosphere interacting with minerals or gases to cause a massive plague, and at least one planet is considered an uninhabitable "black rock" because the terraforming never took.
- Red Dwarf did it twice, both due to Rimmer and both resulting in complete catastrophe.
- The first episode, "Terrorform", was based on a sentient moon which formed itself based on the psyche of those who landed — and it's long been established that Rimmer's psyche is not a good place to be...
Dave Lister: Remember, it's Rimmer's mind out there. Expect sickness.
- The second time was "Rimmerworld", where Rimmer, abandoned to his own devices (by his own cowardice) on an uninhabitable world for 600 years armed with only a planet seeding pod, creates a Single-Biome Planet of Rimmers — he lasted barely forty years before being slung in jail by the rest of him.
- Terraforming was the backgound plot of Back to Reality: Planet engineers in an ocean seeding ship had terraformed an ocean moon and created a marine ecosystem teeming with lifeforms by vastly speeding up evolution. Unfortunately it backfired when one lifeform arose that wiped out everything else: the Despair Squid.
- The first episode, "Terrorform", was based on a sentient moon which formed itself based on the psyche of those who landed — and it's long been established that Rimmer's psyche is not a good place to be...
- Stargate SG-1 has two whole galaxies full of planets terraformed by the Ancients and the Goa'uld, complete with Transplanted Humans.
- They also had a "pyroforming" species, similar to the Andromeda example above.
- Except these were Actual Pacifists, who wouldn't fight back when they were attacked by the Goa'uld. They have no problems "pyroforming" a world filled with plant and animal life (indicating they aren't completely "nonviolent"), but on the other hand when they learn that sentient beings (namely, some of the aforementioned transplanted humans) have made their home on the planet, they are understanding and do their best to help.
- They also had a "pyroforming" species, similar to the Andromeda example above.
- Star Trek: Enterprise has Mars terraforming in-progress. They had the atmosphere thickened enough to allow people on the surface without pressurized suits, and that's about it. By 2155 you still need oxygen tanks and thick clothing to stay alive.
- Star Trek: The Next Generation had a surprisingly good first season episode where the Enterprise was trying to help terraform a desert planet by pumping water for irrigation. Unfortunately, the planet was occupied by sentient lifeforms who were annoyed enough at the attempt to terraform to sabotage the drill. It took a while for everyone to figure this out because they were microscopic silicon lifeforms, and so were mistaken for parts of the sandy scenery.
- However Federation Terraforming regulation require a planet to be devoid of any trace of life, so not even possible future species might be prevented from evolving naturally.
- The Twilight Zone 1980's remake episode "Voices in the Earth". All life on Earth was wiped out and the planet made uninhabitable by a disaster a thousand years ago, including changing the atmosphere to methane. At the end of the episode a group of ghosts restores the biosphere, including changing the air back to normal, recreating life in the oceans and accelerating its evolution.
- The Neo Frontier of Ultramn Dyna was a terraforming project to colonize the solar system. during the series itself, Settlements had been created on Mars.
- In Defiance the Votan terraformed at least one planet in their home system and brought the technology with them to earth. They decided not to use it when they found that earth was already inhabitable and inhabited but when the Arks were destroyed the equipment they were carrying malfunctioned and created a variety of bizarre hybrid creatures when it crashed to earth.
- On Series/Space1999, the Moon is terraformed to have a livable atmosphere by aliens on the episode "The Last Sunrise". They did it because they believe real hard that Humans Are the Real Monsters, the terraformed Moon's atmosphere makes it impossible for the Alphans to deploy ships to check the Moon (let alone visit other planets), and they remove it once the Moon is too far away for the Alphans to explore their planet (which they foresaw as a massive potential contaminating hazard and didn't wanted to take their chances).
- The Mutant Chronicles universe has a terraformed Mars and Venus.
- Let's not forget about various asteroids, moons and the caves on Mercury.
- In the Centauri Knights setting for Big Eyes, Small Mouth, the planet being colonized has had its ecosystem wiped clean to the bedrock by nanomachines made by the natives. The native ecosystem survives on a couple of still-working, but unoccupied, space habitats near the planet. One of the conflicts in the game's politics is: do we terraform the planet into a new Earth, rebuild its own ecosystem by transplanting from the colonies, leave it a barren desert and mine it for technology, or abandon it and go home?
- In Yu-Gi-Oh!, there's a card called "Terraforming" that lets you search your deck for a field card. You literally make the environment more friendly to your creatures — whether human, beast, angel, demon, crystals, etc.
- In Warhammer 40,000 this is done by two factions, inverted by another, and subverted by a fourth.
- The Imperium still has the know-how to terraform planets that aren't already inhabitable by humans, but may end up turning them into Polluted Wastelands dotted by hive cities and manufactorums regardless.
- Back at the height of the Eldar empire, the aliens started long-term alteration projects to make some worlds on the galactic fringe inhabitable. Ten thousand years later these Maiden Worlds have developed into pristine paradises that unfortunately are very attractive to human colonists. Often the first sign that humans have settled a Maiden World is an Eldar warhost bent on exterminating the vermin infesting what they consider part of their ancestral empire.
- Inverted by the Necrons, whose idea of creating the perfect environment is to purge it of any and all life, down to the molecular level if necessary.
- The Tyranids use a process called Tyranoforming on worlds they take an interest in, seeding their atmosphere with spores that bring about runaway plant growth and global warming as Tyranid structures begin to emerge in the overgrown landscape. This is actually a subversion, however - the explosive plant growth is in anticipation of the world's harvesting. The digestion pools and capillary towers help the Horde of Alien Locusts consume every last bit of bio-mass and pipe it up to the hive ships in orbit, which proceed to eat everything down to the bedrock, drink the world's oceans, and even siphon up its atmosphere, leaving behind a barren rock. They eventually want to do this to all of the galaxy, though there is at least one system they're avoiding because it scares even them.
- The Orks can also do this, thanks to their spore-based biology. Left unchecked, Ork spores will gradually "Orkyform" entire planets. Orks are, in fact, even more virulent than the 'Nids in this regard. Where the Tyranids use a complex system of vanguard organisms, hive fleets and other specialized organisms, every Ork and related organism (orkanism?) contains the DNA of the entire Ork ecosystem (Orkosystem?) in its body. Once a spore lands in a spot with the appropriate resources, it will first form plants and fungi, then lesser orkoids like Squigs and Gretchins and finally proper Orks. The only thing that stops them from orkyforming the entire galaxy, let alone completely overtaking the ecosystems of most planets they wind up on, is that, unlike the hive-minded Tyranids, the Orks are Chaotic Stupid incarnate and so inveterately belligerent that they quickly resort to killing each other whenever there's nothing else around to fight.
- Buck Rogers in the XXVth Century. Mars, Venus and Titan (the largest moon of Saturn) are all in the process of being terraformed.
- Life on most of the Known Worlds in Fading Suns is supported by ancient terraforming engines, unfortunately many of them are now failing.
- In Eclipse Phase the Planetary Consortium is terraforming Mars as part of their plan to make the planet transhumanity's new home, at the current point genetically modified "Ruster" morphs are capable of breathing the atmosphere. They were planning to do a similar thing on Venus but when the Morningstar Constellation seceded they adopted a more cost-effective plan to only alter the upper atmosphere (where the majority of Venusian habitats are located anyways). The Pandora Gates have been used to discover dozens of more easily terraformable planets (as well as a few that don't need it) and the TerraGenesis hypercorp has made it a speciality of theirs. Finally the Reclaimers hope to eventually re-terraform earth.
- In GURPS Transhuman Space terrraforming was started illegally on Mars by an anarcho-capitalist group called the Duncanites. After driving them off world the countries colonizing Mars decided the damage was done and continued the project, in 2100 modified humans can breathe the atmosphere. The Duncanites are currently attempting to terraform Europa, and at war with environmental activists trying to protect the native (microbial) ecosystem.
- In Hc Svnt Dracones Mars has been turned into practically a lower-gravity copy of (pre-nuclear war) Earth, while Venus tried to preserve as much of the original landscape as possible and the eco-engineers got a bit creative with the flora and fauna. Ganymede also has a breathable atmosphere but it's so cold that most of the population still lives in domes. While Transcendent Technologies Inc only terraformed Europa a little bit for their research into the Monolith.
- Mata Nui does this as he reforms Spherus Magna in BIONICLE, making parts of the desert Bara Magna into jungle, mountains, etc.
- In Command And Conquer 3 Tiberium Wars, it's revealed that the onset of Tiberium on Earth was part of an alien mining operation. The Scrin seed worlds with the substance, which leaches resources from deeper within the crust and brings them to the surface in the form of green (or blue) crystals which can then be converted into just about anything. Any native populations will naturally seek to utilize this miraculous mineral and fight for control of it, while at the same time Tiberium's mutagenic properties will corrupt native lifeforms and the world's ecosystem. So, both directly and indirectly, Tiberium serves as a Depopulation Bomb that lets the Scrin descend upon a planet all but unopposed before harvesting the crystals at their leisure. The only reason they can't do the same to Earth is because Kane tricked the Scrin into arriving early, in the middle of a world war.
- Sid Meiers Alpha Centauri has terraforming as a big part of the gameplay, even allowing you to decide how much you want to incorporate the native environment (which is a good idea, because this environment fights back!).
- The Spiritual Successor Civilization: Beyond Earth has three main paths for your faction to take: Harmony, Supremacy, and Purity. Only the Purity path involves terraforming the planet to be more Earth-like in order to allow humans to breathe the air (it's normally poisonous). The other two paths, instead, focus on adapting the human body in either the biological (Harmony) or technological (Supremacy) manner to survive on the planet without the need to terraform it.
- Freelancer has no terraformed planets, but instead has terraforming planets like California Minor. It also shows a little bit of the process with Planetform, Inc., the company that handles terraforming operations, and by letting you trade stuff like terraforming gases, alien organisms that eat carbon dioxide and release oxygen, and H-Fuel to power these operations. The game also features the Gaians, a rebel faction of Well Intentioned Extremists who firmly believe that terraforming is the same as ecocide.
- Not that all these efforts are successful. A Planetform NPC in Bretonia mentions that the efforts to terraform a planet in Bretonian borders has had mixed results. Although habitable, the planet is mentioned to be suffering from bouts of extreme weather and the NPC mentions it will revert to its original state as soon as Planetform packs up and leaves.
- Inverted in Half-Life 2 when the invading aliens, the Combine, aim to strip the planet of its atmosphere and water leaving it desolate and uninhabitable. An effective reverse terraform.
- The Mycon in Star Control 2 use their "Deep Children" to pyroform worlds to their standards.
- In KOTOR II, one of the planet/levels that you visit, Citadel Station, exists for this purpose. This is unique, however, in that the planet, Telos, was originally habitable, but the Sith razed the planet for no particularly good reason.
- UFO Afterlight has this as much of the point. Humans, forced off of Earth, travel to Mars to create another habitable planet. Terraforming technology very slowly changes the red planet to a blue and green planet in real-time, and tactical combat maps change from red and deadly to green and (relatively) safe. In fact, if you fail to start the terraformation process shortly after the beginning of the game, the environmental hostility will quickly go out of control, and your space suits will not protect you. The terraformation is also shown in "stages", with the dead, red planet as stage 1, small "plant" organisms and cacti as stage 2, and the appearance of water and more complex organisms as stage 3.
- Terraforming Mars is mentioned in Doom 3. You have to go outside a few times, and you can last only a few minutes.
- In the first two Master of Orion games, terraforming goes on for much of the game. Together with the tech for planetary gravity generators, radiation shields, enriching biospheres and installing biospheres, it's possible to transform an empire into a verdant garden where previously inhospitable planets have between three and fifteen times their original population limits. In the second game it's then possible to fashion asteroid belts and gas giants into new planets and terraform them as well. It's great fun for those who get attached, and well out of place in games of galactic politics and warfare where genocide is what's for dinner. The third game has Spore — like circles and something about "Terra approxima".
- Interestingly, despite the ability to take a gas giant, squeeze it into a rock, and turn that rock into a lush world, you can't de-toxify a planet. Possibly, an oversight on the part of the creators. The only alternative is to destroy the planet with a Stellar Converter and then rebuild it into a world of your liking.
- Galactic Civilizations 2 has three levels of terraforming techs that improve the quality of your already-inhabited worlds, while the first expansion introduced planets with extreme conditions - high gravity, radiation, toxic atmospheres, etc - that required expensive technology to be researched before you could even settle them. Meanwhile, one particular mega-event involves someone randomly poking a Precursor artifact that immediately turns every uninhabitable world within a couple of parsecs into a verdant planet (including, oddly, the gas giants), sparking a galactic scramble to settle as many of them as possible or a major power shift if it goes off in the middle of someone's empire.
- The old 4X game Ascendancy had terraforming as something that could be done only after discovering a fairly high-level technology. In this game, all territory considered of "squares", which could be different colors, each color corresponding to its suitability to different tasks (green for prosperity, red for industrial, for example). Black squares were uninhabitable (except to one species) unless terraformed. Further, the Lush Growth Bomb project increased the maximum population of a planet.
- Very mild degrees of terraforming take place in Mass Effect, as the process is noted to be extremely expensive. Generally, the various species just look for planets that can sustain their biologies naturally, which are few and far between.
- However, in the Arrival DLC for Mass Effect 2, it's revealed that the Batarian Hegemony has been trying for years to force Aratoht to support life via heavy importation of cyanobacteria. According to the codex, after 23 years of labor, their efforts have resulted in a 1% increase in atmospheric oxygen.
- Interestingly, it's also suggested in the codex that some degree of terraforming is taking place on Earth in an attempt to undo the environmental damage that resulted from present day burning of fossil fuels.
- Present in Spore, where using various upgrades to your starship, or purchasing other, various, one-shot machines, you can improve the "T-score" of a planet (which range from T-0 to T-3), which allows it to sustain life better, which, in turn, allows you to plunder it for more Spice to sell. It can also be used to kill all Grox on a planet by raising the T-score to at least 1. Colonized planets can only sustain a number of settlements equal to the T-score. T-0 planets can be claimed by placing a colony, but they will not be able to produce any spice until the atmospheric conditions are improved and then a basic ecology is introduced, establishing a T-score of at least T-1.
- It's also possible to deterraform a planet, lowering the T-score, reducing its habitability and extincting its indigenous lifeforms. Doing this on a foreign planet is considered an act of war (while improving a foreign planet's T-score can earn you their gratitude). It is, however, one of the simplest strategies for wiping out or conquering the home-world of a hostile race before your ship has top-tier weaponry available. Home-worlds are almost always T-3s with extra settlements (as many as 10 fully defended sites with fleets of defending ships). Using terraformer tools to lower the T-Score even a single level will wipe out almost all the settlements, leaving the place far more vulnerable to conquest or extermination and recolonization.
- Star Fox: Andross apparently planned to terraform Venom, a rather barren planet with acidic oceans. In Star Fox Command, this becomes central to the better endings since these oceans are also the home of the hostile Anglar. In 2 endings, his invention is used successfully and causes Venom to be as fertile as Corneria.
- The simulation game Outpost had terraform-buildings available in the late game. Of course, it took an inordinate number of turns for them to complete their job, and successful terraforming provided no real benefit over the life-support buildings you had since Turn 1.
- Outpost 2, in its Genre Shift to real-time strategy, made terraforming into the cause for the game's plot — a huge increase of natural disasters and the unleashing of an all-consuming biological nightmare likely to be The End of the World as We Know It. Second world, that is — Earth was already gone by that time.
- Perimeter has terraforming as important game mechanic. Not so much terraform the whole planet as local area, but idea's the same.
- In Machines Wired For War, this is the Machines' primary function before they get into a war.
- In Imperium Galactica II you can use Genesis-type devices on planets that explosively terraform them to your civilization's needs.
- Another 4x game, Sword of the Stars, has terraforming as a mandatory part of colonization. You can get techs that boost terraforming speed and the range of environments that are cost-effective to terraform, though some planets will always remain out of reach. However, since up to five different races can live on a planet at a time, all with different ecological backgrounds, sometimes some population juggling is necessary. It's possible for a race to colonize planets that are completely inhospitable to another - and conquering these planets instantly pops their habitability zone right to yours (when using assimilation plague missiles). Useful when most planets are hostile.
- The "aliens" in Hostile Waters embark on a great xenoforming project of Earth itself, starting with Greenland. Given that they are, in part, living universal constructors, it becomes of vital importance to stop them.
- Haegemonia: Legions of Iron has terraforming capabilities for all races. Planets can be sorted into four groups: for humans, the first group is gaia/terran/oceanic (can be colonized from the start), the second is forest/swamp/desert/arctic/plains/volcanic/rocky (needs research), the third is barren/acidic (needs more research) while the final one is gas (uninhabitable). Kariaks and Darzoks have different qualifications; for example, both like barren. If it's not good enough, it can be terraformed once which improves the quality of the planet; once the next level is researched, it can be terraformed again. For example, level 1 human terraforming can turn plains into forest while level 3 instantly pushes any planet to oceanic/terran. In the expansion The Solon Heritage, spies can actually reverse-terraform, causing an ecological catastrophe (talk about overkill...).
- Final Fantasy IV: The After Years reveals that the Four Elemental Crystals that show up in so many games of that series are actually terraforming implements. They're a bit less reliable than slower methods though, given that their terraforming effects tend to wear off once they're removed or destroyed.
- Egosoft's X-Universe games have terraforming as the event that started the whole series. After a glitched software update, the Von Neumann machines that man had sent out to terraform the gate system started "terraforming" everything, including inhabited planets and ships. Mankind fights back, the terraformers swat them out of the way, and all seems lost until they're tricked into moving en masse to a distant part of the universe — which they promptly start terraforming as well.
- Escape Velocity: In these games, Mars was always the first planet to be terraformed. And it always went very, very wrong, and the next few hundred years are spent trying to fix the mess. The third game, EV Nova, lets you see somebody get terraforming right in one quest line. And the Polaris have largely mastered it, with several planets listed as terraformed in the "communicate with planet" dialog box.
- Starting from Space Empires IV, you can terraform a planet's atmosphere to suit your population.
- Fallout has an example in the Garden of Eden Creation Kit (GECK), which turns several square miles of nuclear wasteland into a lush, green paradise.
- Fallout 3 featured one side-quest involving a mutated tree and its offspring which are (thankfully) non-hostile and thriving in the wasteland. A small cult has sprung up around worshipping this tree and they believe it may eventually re-terraform the entire planet (or at least the DC area) into a state more capable of sustaining life and human populations.
- Star Wars: The Gungan Frontier has the player setting up a complete ecosystem on one of Naboo's moons so the Gungans can colonize it.
- In Jeff Wayne's War Of The Worlds, much like the novel, the Martians engage in xenoforming with their red weed.
- Champions Online features as a mid-level quest chain fights against the froglike Gadroon who are seeking to Xenoform Earth into a much warmer, swampier habitat — starting in the middle of Canada.
- Lost Planet, though the original plan for making E.D.N. III hospitable would have fried the Akrids and more importantly the colonists already on the planet.
- SimEarth has terraforming machines for its Mars and Venus scenarios.
- Deconstructed in Jak 3: Wastelander, when Jak has to fight the Big Bad operating a massive machine called a Terraformer, meant to be used to fix the unfinished planet. Unfortunately, as it's Dark Maker technology, "fix" here means "ruin and make completely uninhabitable to current life".
- Also deconstructed in Space Quest 5, where a biological agent meant for terraforming planets turns out to have horrible, HORRIBLE effects on actual living beings, including humans. The company that made it bribes a corrupt starfleet captain to get rid of the stuff by dumping it on "unwanted" planets, which ends up causing something similar to a Zombie Apocalypse.
- Endless Space, another 4X game, features this deep in the colonization and exploration tech tree. However, terraforming a hostile world isn't easy, and there are multiple stages of planet types that must be successfully transformed in order to slowly turn a hostile world into a garden: barren and lava worlds can turn into arctic or desert worlds can turn into tundra or arid worlds which finally turn into terran, jungle, or ocean worlds. Terraforming sideways within tiers, or even down tiers, is also possible. Gas giants and asteroid belts, however, can't be improved at all. In a separate form of terraforming, negative and mixed planetary anomalies such as strong magnetic fields, seismic activity, and toxic environments can be alleviated through other technologies in the same tech tree - the first stage allows the removal of minor anomalies, then later the ability to remove severe anomalies. Played with in that descriptions for remedied anomalies indicate that it's just as often the result of adapting the colony's systems to the environment.
- The Eldan of WildStar have left plenty of these devices on Nexus. Sometimes, it works on a very small, local scale (Deradune), and sometimes, encompasses an entire region (the Northern Wilds).
- Part of the background to Infinite Space. At one point, you visit a newly discovered planet still being terraformed and the resident Mr. Exposition scientist explains how it all works.
- In Warframe, there is snow on Venus and Mars, strongly implied to be due to the Orokin.
- Minecraft, sort of— planting lots of trees to ensure a healthy wood supply is an important part of the game, and if you're in a desert or a tundra it can come off as turning the wastelands into a forest. However, the weather patterns won't change, and creatures specific to your intended biome still won't spawn.
- Terraria, like Minecraft above, lets you plant trees and build mountains and such, but you can also change the surrounding biomes!
- Freefall is set on an alien world which is in the process of being terraformed.
- A Miracle of Science has a terraformed Mars that has become a Hive Mind of post-human and AI inhabitants.
- They also terraformed Venus and Europa to give the rest of pre-singularity Humanity more places to live. In the case of Mars and Venus the process is still ongoing: Venus is constantly raining, while one character (a Martian of course) works on a project to restart Mars' plate tectonics and make the atmosphere self-sustaining.
- In The Inexplicable Adventures of Bob!, Butane, the planet of dragons is a terraformed world in the Kuiper Belt. Jolly the Giantess has been given the job of helping to maintain it.
- In Schlock Mercenary Mars, Venus, Europa, and Luna (Earth's moon) have all been terraformed.
- This becomes a plot point when they visit a planet which hasn't introduced many oceanic species because its economy is based on tourism and ocean resorts. There are a few deaths which look like shark attacks, and the first suggestion offered by a character is that someone made a robotic shark with a robotic jaw to murder people.
- Far Out There uses this to explain its habitable planets (as well as why Trigger grew up in an underground bunker)
- In Campus Safari the Cyantians are terraforming Mars and Venus as gifts for humanity when they make First Contact. Their colony on Mars doubles as a Wacky College.
- In Homestuck, Betty Crocker tries making Earth more like her homeworld Alternia, introducing Alternian life and flooding the planet.
- She also tries to subvert human culture to more closely resemble her species', but it fails miserably because of basic biological differences (really basic differences). Her attempts to genetically alter humans to use the Alternian mode of reproduction and blood castes results in complete extinction.
- In Orion's Arm Mars has been terraformed just enough for genetically modified "tweaks" to live there. Venus, after millennia of terraforming and wars, is practically a second earth. Many exosolar planets have also been terraformed to varying extents, and some alien species such as the To'ul'h have their own versions of terraforming (To'ulforming).
- Some Transformers continuities have a thing called cyberforming, whereby a planet is made suitable for Transformer life.
- In some continuities Unicron was originally created as a quick and dirty terraforming engine by an alien named Primacron. He was meant to eat lifeless rocks and shit out planets suitable for habitation, but he decided to skip step two and absorbed planets of any kind into himself to increase his power.
- In the season 2 finale of Transformers Prime, Megatron tries to use the Omega Lock to terraform Earth into a Cybertron like world (which would have fatal consequences for humanity). Optimus is forced to destroy the Omega Lock, dooming Cybertron in the process, to save humanity.
- Beast Machines ends with Cybertron being turned into a technorganic paradise, with most of the Cybertronians restored as technorganic lifeforms. Unfortunately, this required the Heroic Sacrifice of Optimus Primal, who pulled a Taking You with Me on Megatron.
- In Exo Squad, Mars and Venus were terraformed. This is a key part of the Backstory, since it's the job the exoframes and Neo Sapiens were invented for.
- In Aqua Teen Hunger Force, the crappy clone of Master Shake made by the Plutonians is sent to Earth to "de-terraform" it. This plan is not well thought out. Not only does the clone not feel obligated to do so, it has no idea what "de-terraform" means, or how he'd do it, or if it is in fact a real word.
- Mars has been terraformed in Futurama, as explained in the opening quote. Later episodes, however, show that much of the planet is still desert. Oddly enough, the native Martians that still live there don't seem to have any negative effects from the wholesale transformation of the atmosphere.
- In the Phineas and Ferb episode "Moon Farm", the main characters decide to terraform the moon so that they can take cows there, and make the best ice-cream ever, as detailed in the lost sacred stanza of "The Cow Jumped Over The Moon".
- Super Friends. An inverted version in the 1973-74 episode "Too Hot to Handle" when the Solar Terrarians try to move the Earth closer to the Sun so it will get hot enough for them to move here and live comfortably. Unfortunately, that would make it so hot that humanity would perish.
- This French mini-film about the terraforming of Mars.
- The Earth, in its long existence, has had three atmospheres. The first, composed of hydrogen and helium, is believed to have been blown by the solar wind. The second, believed to have been formed by volcanic outgassing, was around 100 times as dense as our current atmosphere, and composed mostly of carbon dioxide with some nitrogen. This was converted into our current atmosphere by two processes. One, the carbon dioxide was scrubbed by chemical interaction with minerals dissolved in the oceans, forming carbonate rocks. Second, the development of photosynthetic bacteria started producing oxygen, which eventually built up in the atmosphere.
- Venus is basically stuck with a stage two atmosphere, because it lacks liquid water. Possibly something to do with being too close to the sun, and thus outside the habitable zone. Earth had, literally, oceans of water even early in its existence. Where the water came from is still a subject of debate. But water is necessary for the carbon sequestration that removed most of the carbon dioxide from the stage two atmosphere.
- Terraforming planets, by current human technology standards, is possible, but scientists theorize that any such process to turn a completely uninhabitable planet into a habitable one would take hundreds of years, perhaps even a full millennium. Planets that are closer to Earth standard might be capable of terraformation in as little as 300 years. So, don't count on it. (As a point of interest, many scientists theorize that Venus would be a better candidate for terraformation, instead of Mars, due to the fact that Venus is tectonically active, while Mars isn't.)
- NASA's even done studies on the idea of terraforming the Moon into an Earth-like world. While the lunar gravity's too weak to hold a permanent atmosphere, it'd take thousands of years for a newly created one to dissipate, and in the meantime the Moon could conceivably have blue skies, oceans and forests. It seems like a colossal waste of resources by today's standards, but the possibility does exist for any future civilization that really wants to go sunbathing on the Moon.
- One of the problems with terraforming is an ethical one. If, hypothetically, microbes exist on Mars (which is possible), Terraforming would likely lead to their extinction. This may seem insignificant until you realize that humanity has also evolved out of microbial life, so we would potentially be exterminating intelligent life before it is even able to evolve to that point. This is the subject of a lot of debate within the scientific community with some in favor (Mars Society founder Robert Zubrin, for one) and others opposed (such as the late Carl Sagan). It doesn't help that the quickest way to terraform is to explode nuclear bombs all over the surface. Another issue is that microbes or chemicals may have been brought to Earth from Mars via asteroid strikes.
- An twist on this was raised up late in the nineteenth century. If Mars does have microbes then the situation could turn into something out of H. G. Wells The War of the Worlds. At the very least, both the Earth life and the Mars life would have a long drawn out battle with unpredictable results.
- An added difficulty of any theoretical terraforming that real life scientists have seriously discussed is also the issue of maintenance of the terraforming. It would be pointless to expend so much time and effort to terraform a planet only to have it undone. This is one of the reasons why some consider Mars a poor candidate. Mars's core has long since hardened, which means it has no magnetic field to protect life from solar radiation and from solar winds blasting away its atmosphere. The atmosphere Mars now retains is a mere wisp compared to what scientists theorize it may have once had.
- Mars has some issues with potential terraforming, but atmosphere retention isn't really a huge problem. The planet could hold on to a breathable atmosphere for tens or possibly even hundreds of millions of years, unlike a possible terraformed Moon.
- This is largely conjecture, but if the atmosphere is being blown away over millions of years is it really that absurd to import atmosphere to replace it as it is blown away? To even settle Mars at first would require at least some level of casual inter-planitary travel.
- To an extent, terraforming is already happening right now, here on Earth: Human beings have been "reclaiming" land from the sea for centuries, particularly in the Netherlands, Hong Kong, and Dubai.
- Also, this. Darwin did it first.
- European colonists have done this to other parts of the world for centuries, bringing their home plants and animals even to places where local domestic alternatives existed. This has sometimes lead to ecological disasters, particularly on islands.
- The age of a star can change the conditions of whatever planets orbit it as it grows bigger and hotter as it ages by pushing the habitable zone (an invisible boundary where liquid water can exist) outwards. While doing so will render any planet originally in that habitable zone uninhabitable, it will also make planets too cold for life to become warm enough for life to evolve. When our Sun dies in about 5 billion years, this will actually happen to all of the outer planets in our Solar System. In fact, even Pluto may eventually become Earth-like one day!