Alien Sky



""I could see the Earth and Moon in the sky of this strange world, Gaea...That's what they call this place.""

- Hitomi, The Vision of Escaflowne

You've used the Time Travel machine on "random", "borrowed" the professor's rocket ship, or walked through the strange glowy doorway. OK, everything seems normal, but for some reason you can't get your bearings. When you look up... it's an Alien Sky.

Used to bring home the fact that the heroes (and viewers just tuning in) are in another world! Maybe there are two moons. Perhaps Earth's all-too-familiar moon, the one in all the love songs, is broken into so many pieces it's become a ring of debris around the planet.

Having the moon orbit huge gas giants like Jupiter or Saturn that dominate the sky isn't rare, either. In the daytime, the sky could be a lovely shade of purple instead of blue, the sun could be a different color, or it could have a little and a bigger brother.

Sometimes used to comedic effect when our heroes just won't believe they've left Earth for good, and shrug off all other, often painfully obvious, hints as some kind of Masquerade ("Wow, great special effects! I'm on hidden camera, right?").

See also Sci Fi Writers Have No Sense of Scale, which is sometimes invoked for some of the more bizarre sky-types. Compare Zeppelins From Another World. The sub-trope Binary Suns is a specific example.

Anime & Manga

 * Two moons in Zero no Tsukaima and Seirei no Moribito.
 * A huge, red sun in Now and Then Here And There.
 * In Magical Girl Lyrical Nanoha Striker S, Midchilda seems to have, conservatively-speaking, at least six Earth-like planets hanging in its sky for no discernible reason. A number of other planets they visited in the previous season also have this unusually populated skyscape.
 * Rule of Cool.
 * The Vision of Escaflowne had Earth hanging in the sky.
 * The Digital World in Digimon Frontier had three moons.
 * The Digital World in Digimon Savers had rocks floating in the sky and it sometimes had electronic textures on it.
 * The Tamers era had a digital representation of the earth floating in the sky.
 * Digimon Xros Wars had this used, not to show that they were in another world, but that they went from one section of the other world to another section, with the island zone having a pattern in the sky
 * Manabe Johji's Capricorn is set in a Lunar-like alternate dimension in which our Earth is visible in the sky over the moon. The moon is itself a planet with Earth's density and gravity, if not its size.
 * A variation: It's not the sky which tells Youko that she's arrived in the world of The Twelve Kingdoms, it's the alien-looking sea. Later in the series, she flies to a palace on a high mountain and discovers there's another (watery) sea above the clouds.
 * Similarly, it's the not so much the sky itself in Eureka Seven that looks alien, but the luminescent clouds of light particles that blow across it. The ground's not exactly normal, either, what with the huge chunks of coral-like stuff jutting out of it.
 * Tengen Toppa Gurren Lagann played the double moon version during a chapter with the Moon.
 * Darker Than Black has as part of the back story that the normal sky of the Earth disappeared when Hell's Gate opened ten years ago, taking with it all constructs found above the Stratosphere. Attempts to reclaim space only result in silence from whatever is sent up there. Instead, the stars in the night sky are all artificial and bound to a particular contractor, blinking as the contractor uses its power and falling from the sky when the contractor dies. The moon has disappeared and even the sun is altered; every few years, the sunspots move around so much that the sun looks like a giant glowing eye for a while.
 * Simoun takes place on a planet in a binary star system, which accounts for the Fashionable Asymmetry in the clothes design of the Sybillae.
 * In DragonBall Z, Namek has a green sky (and blue grass), and three suns that illuminate the planet's entire surface at all times. And lollipop-shaped trees.
 * In Stellvia of the Universe space, and thus the night sky, is green now. This is justified in that Earth is in a part of space still suffering the effects of the supernova explosion of the star Hydrus Beta ( which almost destroyed human civilisation ) and so occupies what seems to be a nebula..
 * Cowboy Bebop has a cracked moon in Earth's sky and tons of debris that rains down upon the Earth on a daily basis. Of course, few people live there, opting instead for other, terraformed bodies in the Solar System with even weirder views of the heavens.
 * Speaking of space westerns, Trigun appeared to take place on wild west Earth at the beginning, but the twin suns, five moons, and purple night sky caused by three or more moons shining at one time is a tipoff to the contrary...along with all those alien-looking people and weaponry...and those giant Plant systems.
 * Allison and Lillia has, in addition to its Alien Geography, a moon which is much closer to the Earth, orbiting every eight days and producing spectacular solar eclipses on a disturbingly frequent basis. Strangely, however, calendar months are still roughly 30 days long...
 * In Trinity Blood, Earth has two moons: the normal moon, and a new "Vampire Moon", which is
 * End of Evangelion ends up with Earth surrounded by reddish ring . The sky looks even worse in the middle of the film.
 * Sentou Yousei Yukikaze has a hard version of simply making the atmosphere of Fairy green-tinged, with a double star system as its sun.
 * In the Sonic the Hedgehog OVA, a large planet with Saturn-like rings is visible in the sky over the North Pole.
 * In Star Ocean EX, Expel, a medieval Earth-like planet where the action takes place, has two moons, one glowing blue and the other glowing red.
 * This is a major plot point in Brigadoon Marin and Melan. Because of the impending mutual collapse of the two worlds, Brigadoon is visible in Earth's sky for the entire series, and vice versa. (On Submaton Color you can see both worlds at the same time.)
 * In Last Exile Fam the Silver Wing, Earth has six moons. Of course,.
 * Used in Avenger to show viewers that it is really Mars where the action takes places.
 * In Saint Beast, while the sky in Heaven may not make much sense, it's definitely very beautiful.

Comic Books

 * The setting of the Elf Quest comics also has two moons -- and is called the World of Two Moons, in honor of the fact.
 * The planet Elekton in The Trigan Empire has two moons and two suns.

Fan Works

 * In With Strings Attached, at the beginning, when Paul is awakened by John and discovers they're outdoors in a field somewhere, he angrily assumes John spirited him away, despite John's vehement and frightened denials. Trying to find a hidden camera crew, he notes that the full moon is setting over the nearby forest. Then, on the beach, he does a double take when he sees the crescent moon over the ocean... and then he knows John wasn't responsible for this predicament at all.

Film

 * Star Wars had Luke framed against a simple but gorgeous twin sunset in the first movie--it's the first shot in the film to really drive home the point that this isn't Earth, and succeeds spectacularly, despite being one of the film's simplest effects - it's just a double exposure of a real sunset. It also featured the rebel base on an Earth-like moon orbiting a giant, red gas-planet.
 * The 2002 remake of The Time Machine had a cracked moon and debris field circling the Earth, the product of the man-made disaster that prompted the Morlock/Eloi Earth in this version.
 * The Dark Crystal makes a big deal out of the Great Conjunction of the Triple Sun, during which time huge world-changing events are known to occur.
 * The Quiet Earth (see the illustration) ends with Zac on an alien world, or radically changed Earth, immediately obvious because of the weird clouds and ringed planet rising in the sky.
 * The unnamed planet in Pitch Black has three suns, which causes it to be constantly daytime, except once every 22 years, when there is a triple eclipse.
 * The several other celestial bodies in the system (moons and planets, some with rings) that are responsible for the eclipse are also visually impressive.
 * The world Krull rotated around two suns. There were no double-shadows, we never saw the sky enough to find both suns, and there was no plot-significant reason for there being two suns. It was just cool.
 * The Reveal in Galaxy Quest, when the huge dome opens and Taggart finally realizes where he really is.
 * In the theatrical showing, there was another level to this. The opening minutes, where the 'clip' of Galaxy Quest is played, was in 4:3. When this ended, the aspect ratio pulled back to "standard" 1.85:1. When the doors open the ratio was again increased, this time to 2.35:1. The DVD, of course, ignores this.
 * Vanilla Sky. The sky is the same milky orange with white clouds because The film also toys with the perspectives of light, as in certain scenes the sunlight illuminates the set from impossible angles.
 * Stargate (the movie) showed an alien sky with three full moons visible at the same time. This turned out to be the basis for the planet's identifying symbol in the Stargate dialling system.
 * The 1980 version of Flash Gordon features an immense sky full of vivid, multi-colored clouds visibly surging and roiling. The "sky" may in fact be more akin to a nebula, as continent-sized "moons" are seen to float in it. Its relationship to the "Sea of Fire" the heroes fly through to reach Mongo is unclear.
 * Mongo probably orbits a companion star that spins around a red giant that has become a planetary nebula. It looks similar to the Helix Planetary Nebula when Zarkov's ship approaches it prior to reaching the Sea of Fire (the red giant's corona).
 * Mongo may be Jupiter; much surface area, with many moons. The current view of the Solar System at the time the strips were written might support this. Perhaps why the sky is a 'sea of air' filled with colourful clouds, even in the strips.
 * In Coneheads, the Conehead's home planet has three moons. The rare event of all three lining up perfectly in the night sky is commemorated as a holy day.
 * Highlander II the Quickening is set in the future, where the sky has this reddish cloudy color.
 * The "sky" in The Truman Show has an artificial quality, as it's painted/projected against the interior of an enormous dome and the moon is stationary in the same place, day or night. The "moon" is really where the mysterious director of the Truman Show resides and watches over Truman's life, and can in emergencies be used as a giant searchlight.
 * In Avatar, the gas giant Pandora orbits, and its sibling moons, are prominent in its sky - as is, in one scene, either Alpha Centauri B or the drive flame of an RDA starship.
 * In Predators, the protagonists go "we're not on Earth anymore" when at a certain point they see a sky with at least two gas giants.
 * Hunter Prey: A big red planet hangs overhead.
 * Damnation Alley: A symptom of the recently-fought nuclear war.

Literature
"Spock: "Vulcan has no moon."
 * Jennifer Fallon's Second Sons series takes place on a planet with two suns. The driving event of the story is one sun eclipsing the other for a period of many years, allowing a corrupt cult to take over the world.
 * Malacandra in CS Lewis's Space Trilogy has giant chunks of pink coral for clouds, set in an electric blue sky.
 * Due to Venus's thick atmosphere, the Venerean sky is solid gold during the day and pitch black at night.
 * Similarly, in The Magician's Nephew in the Chronicles of Narnia, the sky of Charn is very dark even in daytime, and the children see a second, smaller star (implied to be a white dwarf) close to the red giant that is the world's primary star.
 * The novelizations of Magic the Gathering's Mirrodin block had the four moons (corresponding to four of the five colours of mana) as its main plot element. The third set in the block, Fifth Dawn, is about what you'd expect. The better known world Dominaria has two moons, the Mist Moon and the Glimmer Moon or Null Moon
 * Isaac Asimov's short story (and later, novel) Nightfall takes place on Lagash, a planet with six (!) suns and one moon. This is a major plot point, as when the moon eclipses the sole sun remaining on one side of the planet (after the others have all set), which happens every 2049 local years, Lagash's people go insane and destroy their civilization. It wasn't just the darkness that drove the people insane; it was all the stars in it. Their astronomers had theorized that there might be other star systems, as many as twenty or even a hundred - a number which another character whistles at, commenting that it would reduce their world to insignificance. Earth's sky would be enough of a shock, but Lagash is close to the center of the Galaxy, and the splendor of a star-packed sky - the sudden revelation of how vast the universe really is, and how indescribably tiny they are by comparison - is enough to crush even the most "prepared" mind.
 * The Dragonlance novels are set in Krynn, a planet which initially has three moons. Each one has a color, the larger one is white, the medium one is red and the smaller one is black, and also invisible on regular circumstances. Sometimes the moons align and make a "eye" in the sky.
 * Used to truly horrible effect in the Legends trilogy. Normally, the constellations in Krynn's sky are many, one for each god. When Caramon steps into the future, the sky is empty of stars, save only for a single constellation- an hourglass signifying Raistlin, his twin brother. Every other god had been slain.
 * The Andalite Chronicles, a prequel to Animorphs, has a piece of Phlebotinum create a small universe based on the memories of the main characters. The sky is a patchwork of bright blue with fluffy clouds (Loren's memories of Earth), deep red (Elfangor's memories of the Andalite homeworld), and sickly green with lots of lightning (Esplin 9466's memories of the Yeerk homeworld, problems with that notwithstanding).
 * Near the end of Monica Hughes's Invitation To The Game, the small tribe of main characters believes they're still in a virtual-reality world until they realize that they can see the Milky Way from outside it, and there's no moon.
 * Marion Zimmer Bradley's Darkover has four moons and a dark red sun, colloquially known as "the bloody sun."
 * Dragaera's sky is covered with a reddish-orange overcast as a side effect of using sorcery, making the light dimmer during the day but also less dark at night. When Vlad Taltos ventures outside the Empire, he's taken off guard by the blinding days and pitch-black nights. In Issola, he visits an alternate dimension where the sky is very different from normal.
 * Played with in The Chronicles Of Amber; sky color is one of the ways to tell where you are when walking between worlds.
 * In the Warworld series, the Alien Sky is an important plot point, as the moon Haven has a day/night cycle 87 hours long, so having a heat-radiating Brown Dwarf in the sky can mean the difference between freezing to death and merely losing a few toes.
 * Another Co Dominium setting is the twin planets of New Washington and Franklin, which are tide-locked so that each sits unmoving in the same part of the sky every day when seen from the surface of the other.
 * In the Riverworld series, the sky is moonless, but has brighter stars than Earth, including some still visible in the daytime.
 * Larry Niven
 * Ring World: the Ringworld sky is dominated by the Ring, and "night" is produced by the Shadow Squares.
 * Smoke Ring is, if anything, more bizarre. The "planet" is the sky. The Ring is a (mostly) gas torus from a supermassive gas giant in close orbit around a neutron star, which is a binary with a yellow dwarf.
 * In A World Out of Time, Niven gives us an Earth that has been moved to orbit Jupiter, because.
 * Used in the Star Wars Expanded Universe to drive the point home as to just how powerful the Yuuzhan Vong are - they take one of Coruscant's moons and shatter it, turning it into a planetary ring. This ring and another of the planet's moons were thrown out of orbit when the living (and hyperspace capable) planet Zonama Sekot entered the system in the last NJO book.
 * In other novels sky colors are occasionally mentioned. Not a color as such, but it's said that Coruscant, with all that pollution, has an unbelievably beautiful sunset.
 * Gene Wolfe's Book of the New Sun is set so far into Earth's future, the terraformed Moon is covered in green forests, and the sun has dimmed to the point that stars are visible in the daytime.
 * In the novel Under Alien Stars, the title actually refers to the alien character in the book (which involves Earth becoming a backwater world between two empires who are at war), since pretty much the entire book is set within Earth's gravity well. That is, it is Earth's sky that is alien.
 * Against a Dark Background by Iain M Banks is set within a lone solar system that is outside a galaxy. This is revealed two-thirds through the book, but hinted at a several points, notably in night-time scenes where starlight is not mentioned but "junklight" (light reflected from satellites & space junk in orbit above) is.
 * Pern has two moons--Belior is the larger one, Timor is the smaller one. Since the dragonriders often use the moons' positions as coordinates for going between, it's likely that they can be seen during the daytime. However, the plot-important aspect of the sky is the Red Star, which starts raining Thread onto the planet once it gets closest to the sun.
 * In Dan Abnett's Gaunts Ghosts novel His Last Command, when Mkoll and Maggs have gone through a Chaos warp gate -- the stars are all wrong, and there are massive stone blocks floating in the air.
 * In Graham McNeill's Warhammer 40000 Ultramarines novel Dead Sky Black Sun, not only is the sun black, it never moves.
 * Perry Rhodan had for Earth or alternate main mankind worlds:
 * A failed teleport put Earth and Moon in interstellar space, with "atomic suns" in orbit providing light and heat, then was moved into a system with a red star.
 * During Earth's absence, the main human world was Gaea, around a normal star, but inside a dark nebula.
 * The newest "main" human worlds are in the Stardust system, with the 3rd to 6th planet habitable, the main (4th) having 2 moons, the 5th 4 moons, several gas giants further out in the system - and the system is in a globular cluster so it only really gets dark when it's cloudy.
 * The planet Krikkit from the Hitch Hikers Guide to The Galaxy is an example of an alien lack of sky, there are no visible stars or moons because the entire planet is surrounded by a dust cloud.
 * In The Pedragon Adventure, the territory Denduron has three suns. Eelong has a "sun belt," a thin line of sunlight that crosses the entire sky.
 * In The Wheel of Time, the prison of the Dark One is accessed through a simple tunnel into the mountain Shayol Ghul – but the view from the inside is "a sky that was not the sky of" the normal world, with "wildly striated clouds streaking by as though driven by the greatest winds the world had ever seen." Given the other atmospherics and the fact that the Pit of Doom is literally outside the universe, this may just be to freak visitors out.
 * Inverted in the Diane Duane Star Trek novel Spock's World, in which Sarek finds Earth's tiny, silvery moon a bizarre spectacle that helps him come to terms with the idea that he's really on another planet.
 * In one TOS episode Uhura flirts with Spock, asking him what his planet looks like under a full moon.

Uhura: "I'm not surprised.""


 * Godspeaker Trilogy takes place on a world with two moons, a large and a small one. The Mijaki call these "the godmoon and his wife". Whether the other cultures of the world have their own names for the moons is never mentioned.
 * The Fantasy Counterpart Culture novels of Guy Gavriel Kay (like Tigana) take place on a world with two moons.
 * The appearance of the first clouds to appear over Fourecks for thousands of years invoked this trope in The Last Continent for some local Discworld wizards, who'd never seen such a thing before.
 * Lisanne Norman's Sholan Alliance series puts the action on the distant planet of Shola, which has two moons. One of which is missing a large chunk.
 * Mars' twin moons Deimos and Phobos feature prominently in the descriptions of Barsoom's night sky in the John Carter of Mars novels.
 * The planet Erna of the Coldfire Trilogy has three moons--Prima, Domina, and Casca.
 * In Clive Barker's young adult fantasy book Abarat, it's seeing the unfamiliar stars in the sky that really hits home for Candy Quackenbush that she's in another world.

Live Action TV

 * The Sliders episode "State Of The A.R.T." changed the color of the sky to lilac. The Ridiculously Human Robot gives it a Hand Wave about pollution particles-- not one that makes scientific sense, of course, but at least it was acknowledged.
 * Later episodes brought us green skies (for worlds hidden in hyperspace), and a sky with a moon plus two additional Earths (incorrectly said to be "in syzygy.")
 * Space 1999 actually takes place on the moon after it's been blasted out of Earth orbit and the solar system.
 * Doctor Who: Pick an alien planet, it's there.
 * The Time Lord homeworld Gallifrey is perhaps the most well-known example with its fabled "burnt orange sky", although the Doctor never arrives there at random (and it isn't shown on-screen much at all).
 * An early example was the planet Vortis, in "The Web Planet", which had an atmosphere so thin that the stars (and multiple moons) were visible during the day.
 * During the eighties, a particular new postproduction technique resulted in a minor run of planets with pink skies, including Thoros Beta in "Mindwarp" and the unnamed planet in "Survival".
 * A story arc in the eighteenth season upped the ante with a trip to the pocket universe E-Space - where, of course, all the planets had a particular sort of alien sky
 * Only at night - space was green in that universe (and since it was later established that inter-universe portals were built to drain off entropy, entropy is green.
 * The planet Krop Tor in The Impossible Planet had a large black hole in the sky, as well as hurricanes created by whatever said black hole is currently consuming.
 * Pylea in Angel has two suns, not that we see either more than once. Conveniently for any vampires present, neither are of the undead-frying variety.
 * The Land of the Lost has three moons (and sometimes two suns), but given what's learned about the Land during the series, they may not be exactly... real.
 * Planet Hell (the "planetary surface" soundstage) from Star Trek the Original Series, which always had a different-colored backdrop. I mean, sky.
 * And the "demon-class" planet, which had both Alien Sky and Alien ground.
 * An Egregious example is when Vulcan was seen in Star Trek the Motion Picture with two really big moons in the sky, even though it had previously been said that Vulcan doesn't have any moons. A Fan Wank Retcon turned these into a sister planet with its own moon ... And then the eleventh movie actually put characters and a starbase on the sister planet so one of them could watch in a flashback.
 * The planet Vulcan is supposed to have a red sky, and no moon - though an animated episode shows a huge disk hanging the sky, usually explained as a twin planet of some kind.
 * Stargate SG 1 loves putting many moons and big moons into an alien sky - probably because nine-tenths of the planets look like British Columbia, so you have to show variation somehow. The trend started in the Stargate film, where Abydos has three moons. This trope was used quite well in any episode where Muggles were invited through the gate; they'd say the planet looks just like earth until either they encounter alien technology or a cast member tells them to look up... at the gas giant or pair of moons in the sky.
 * Firefly does this all the time, as the series is set in a solar system with lots of gas giants and habitable moons. The "first episode" features, in its first scene a celestial object hanging in the sky that you really wouldn't want to see on Earth, because it would mean the moon had suddenly and drastically reduced the distance between itself and Earth and altered its surface features.
 * Power Rangers often depicts alien planets as generic rocky wastelands... but with a color filter over the camera so you know it's definitely not Earth. The Earth's moon (which has a breathable atmosphere, by the way, ever since the first season), has a distinct blue colour, while the hot planet Kalderon has a red atmosphere. Etc.
 * Done on Earth in Power Rangers RPM, to show just how much damage Venjix has caused. Outside of the Domed Hometown of Corinth, which projects blue skies onto the underside of the dome, the world is covered with a yellow filter to suggest yellow toxic clouds, high radiation levels, and storms of dust.
 * The skies of Arrakis in the miniseries Dune deserve a special mention because of the final shot. The hero and his new wife are depicted silhouetted dramatically against a sky which has two moons - in different phases. The creators were going for Alien Sky, and ended up with something way more alien than they were hoping for. Anyone else see a problem here?
 * Well, if two moons are at different points in the sky, then the viewing and lighting angles would be different, and the moons would be in different phases. For example, if the sun has just set in the "west", one moon is in the western part of the sky, and another moon is in the eastern part of the sky, the first moon would be a crescent while the second would be more gibbous. The problem with the scene at the end of the Dune miniseries is that the moons are almost in the exact same position in the sky and are still in significantly different phases.
 * The David Lynch Dune movie had a colour process where the film shot 'on different worlds' was processed to give a different colour palette; Gold for Kaitain, Green for Caladan, etc.
 * In the Tin Man miniseries, when DG first wakes up in the O.Z., she finds herself in a huge forest with two suns in the sky, just to make it clear that (all together now) she's not in Kansas anymore.

Music

 * In the music video for The Sword's "Fire Lance of the Ancient Hyperzephyrians", the moon is cracked during a global nuclear war. This corresponds to the lyrics, "Within a shattered planet, beneath a broken moon."
 * Surely one of the most iconic examples in music is the video for David Bowie's Ashes to Ashes, in which the sky is black.

Tabletop Games

 * Many Dungeons and Dragons settings have multiple moons.
 * Greyhawk has two moons.
 * Dragonlance has three morally-aligned moons -- Solitari (good, white), Lunitari (neutral, red), and Nuitari (evil, black) -- but only so long as the gods are around.
 * Also, they have a constellation for each of the gods, which vanish from the sky when their god is wandering about on Krynn.
 * Eberron has a whopping twelve moons, and it is said that there was once a thirteenth. To top it off, it also has a ring composed of dragonshards.
 * Toril (Forgotten Realms) while only having one moon (Selûne), has visibly trailing behind it a string of asteroids (called Selûne's Tears). Plus, it's also worshipped as a goddess. Or seen as a personification of goddess. It's complicated.
 * And if you roam the Realmspace, Selûne is inhabited, but they think entire Toril wants to conquer them so entire visible lifeless surface is an impenetrable illusory disguise woven by a goddess (and not the same goddess). But then, for Spelljammer it's not too weird.
 * A late 3.5 sourcebook suggested the Tears may be a result of what sounds somewhat like a Giant Draconic Ground-to-Space Fantasy Death Ray missing its intended target (a certain comet) and hitting Selûne instead (which may explain why the Selûnites regard Toril as they do...).
 * The Iron Kingdoms setting uses three moons, on very different orbital planes. It is mentioned that the interplay between the moons causes violent and unpredictable tidal effects and maritime weather.
 * Wilderlands of High Fantasy features a ring of asteroids in the sky, which change colour every few hundred years.
 * Mystara has two moons, one of which is invisible, the other of which is home to the gods.
 * Different Clusters within the Ravenloft setting may have different constellations, and specific domains' skies may differ in other ways. Bluetspur's sun never rises, but traces a path just beneath the domain's mountainous horizon; the Nocturnal Sea's skies are always overcast.
 * In Dragon Mech the moon has been pulled closer to the world, such that giant rocks (and occasional creatures) are raining down from it, and thus takes up about a third of the sky in most of the art.
 * In Elder Evils, the arrival or awakening of an Elder Evil is preceded by a sign. Among the many possible signs provided is Alien Skies.
 * Warhammer features a world with two moons, one normal looking, the other a sickly, evil green.
 * The green moon is actually made entirely out of the powerful, but incredibly dangerous magical substance known as Warpstone.
 * Warhammer 40000 has this in spades - pretty much every planet has, or is implied to have, a screwed-up sky to some extent. Considering the million-something habitable worlds that make up the galaxy, that's quite a lot, and it's pretty much justified, as well. A Warp Storm over a world is liable to induce the most horrifying variety of this, too.
 * This also includes Earth/Holy Terra, if you're curious. The inhabitable ecumenopolis (planet-covering city) sees a sky of smog, pollution and storms, but on a relatively clear night you can see the moon... Because it's covered with just as much infrastructure and glows brightly. If you're actually down on the surface (and not dying from millenia of refuse, toxins, radioactive waste/fallout and Warp filth) then you'll have a lovely view of the underside of the foundations of said planet-city.
 * Exalted
 * Yu-Shan, the celestial city and home of the gods, has the sky change depending on which god is currently winning the Games of Divinity.
 * Also, it has Malfeas, home to The Legions of Hell, whose fake sky is lit by a green sun, which is itself an exceptionally powerful demon.
 * A sun which is stated to have shared the sky with the Unconquered Sun before the Primordials were overthrown.
 * You can punch it.
 * Creation's physical sun and moon are gigantic artificial structures piloted across the sky, both of them entirely viable adventure settings in their own right.
 * In Magic the Gathering, Dominaria has two moons. One of them is artificial. And Mirrodin has four (and later, five) "suns."
 * Don't forget Esper, with its star chart for a night sky and bisected clouds.
 * The Lost World of Zorandar, the setting for the Lands of Mystery supplement for the Justice, Inc. roleplaying games, has three suns.

Video Games

 * In Fusionfall, the show mash-up game from Cartoon Network, if you look up, you can see the evil titular planet(Planet Fusion) with half-swallowed planets from our solar system in it.
 * Skies of Arcadia deserves a special mention here. Six moons (and no visible sun, despite there being a normal day/night cycle), and they're arranged in such a way that you can only see each one in a particular region of the world. Besides the Moons hanging over their country of choice, just try to fathom how that map works when you really think about it. (The two ends of Glacia should not be connected to each other if the world is round...) Of course, the game is premised on the assumption that there's no ocean and all the landmasses of the world are floating in the sky, so maybe we should just relax.
 * Lunar takes place, appropriately enough, on the moon, so it has a huge floating Earth in the sky.
 * The Ratchet and Clank series, taking place on multiple worlds, naturally gives a good number of odd skies to look at when you're not blowing everything to Kingdom Come.
 * Tools of Destruction has a memorable part during the final battle. You teleport to another dimension, where you fight above a raging black hole against a crashing asteroid ring.
 * From the same developer: Insomniac Games did the same thing with their Playstation 1 Spyro games. Enchanted Towers from Spyro 3: Year of the Dragon is one example.
 * One of the many links between Tales of Symphonia and Tales of Phantasia is the names of Phantasia's two moons: Sylvarant and Tethe'alla, the names of the two worlds in Symphonia. When the original world was split in two, the residents of each world named the one moon that remained in their world after the other world, to "explain" where the missing people went. This caused some confusion when someone from the world of Tethe'alla came to Sylvarant (whose people had long forgotten about the other world).
 * Not to mention that after the magical seal holding Sylvarant and Tethe'alla together, the both world's skys get all purple and cloudy.
 * The world of Chrono Cross has two moons, one large and familiar-looking, the other small and red. Its predecessor Chrono Trigger, set in the same world, only had one..
 * Many of Psygnosis's Amiga games, usually featuring a blue-to-pink/green-to-pink gradient and an impossibly large moon.
 * In Freespace 2 a scouting expedition is send through an ancient subspace portal. The other side of the portal lies deep inside a massive stellar nebula that limits sensor range to a few kilometers and visual range to only a few hundred meters, while usually being of a pale blue or green color. One infamous, but optional mission takes place in the center of a massive electromagnetic storm that completely shuts down sensors and missile targeting, while turning the vapors to an almost black dark red, with massive lighning discharges all around you.
 * Sid Meiers Alpha Centauri is set in the Alpha Centauri star system, which consists of two mid-sized, sunlike stars (Alpha Centauri A and Alpha Centauri B) and a red dwarf (Alpha Centauri C or Proxima Centauri). The planet you colonize (officially called Chiron, usually called Planet) is the second planet of Alpha Centauri A; Alpha Centauri A and B orbit around each other in an 80-year cycle. Since the orbit is elliptical, this means Alpha Centauri B's actual distance from Planet varies noticeably, and every time Alpha Centauri B approaches perihelion (i.e., gets its closest to Alpha Centauri A) Planet gets warmer, causing the native life to pester your bases even more for a period of 20 years. However, you rarely get to see the actual sky of Planet in cutscenes.
 * The name of the trope is also used, when the opening video refers to the settlers seeking a new life "beneath an alien sky."
 * Drakengard
 * After the final seal is broken, the world's sky turns from a happy blue to a blood-red. This also accompanies fireballs that rain from heaven and explode with the force of a nuclear blast, turning your recent major military victory into a devastating loss.
 * In the bonus level of Drakengard, Caim and his dragon emerge in . To emphasise that it's an alien dimension to them, everything is disturbingly in black and white.
 * The first few levels of Serious Sam: The Second Encounter are supposed to take place in South or Central America, on our Earth, in the Mayan age. However, as you near the end of this set, the sky goes completely dark, and a bit later on the night-time sky is blue-purple and... is that a nebula? Cool and beautiful but quite bizarre.
 * The Elder Scrolls Series features two moons in the sky: Masser and Secunda. One of these moons is reddish-brown while the other is grey. Oh, and when the moons aren't full, you can see stars behind the dark parts (A Wizard Did It) The constellations and nebula shown on the night sky are also completely different, creating a beautiful spectacle. In Oblivion, the skies are even wierder, even during daytime.
 * The moons are actually the rotting corpse of Lorkhan.
 * more like all being the crazed schizo mind of the godhead. Tamriel is little more than a guy with sensory deprivation hallucinating to an unholy extreme.
 * In the second game, the sky would occasionally turn green for a few hours, with no reason given. Perhaps it was a bug; perhaps it was intentional and meant to drive home the point that Tamriel isn't Earth.
 * Concept art and early beta footage of Elder Scrolls III: Morrowind having a daytime sky that is a pleasant shade of orange. This was scrapped in favor of a normal blue one.
 * Also in Morrowind, the sun is fucking huge.
 * In Oblivion, entering the eponymous Oblivion World lands you in somewhere closely resembling hell, with a red stormy sky. Going near an Oblivion Gate in Tamriel causes the same sky effect, which can be very unsettling.
 * Indeed. The game can shift from a rainy, grey sky to a weather-less monstrosity that looks like it's been set completely on fire.
 * Shivering Isles, Shivering Isles! It's gorgeous! Huge, multicoloured stars and nebulae streaked across a deep purple night like paint on a canvas...the first time you enter the Isles and look up, it's hypnotising. And it changes (becoming no less alien and beautiful) depending on where you are.
 * Including a large, distorted line going the length of the sky, which follows the single prominent border in shivering isles, for its entire length.
 * Skyrim continues this trope in fine fashion, not only including many of the aforementioned delights, but also with some spectacular auroras going on. Whilst they fit with the northern, snowy province, they are far more extravagant than those featured on Earth and come in some pretty otherworldly colours. One of the Dragon Shouts you can learn even clears away all the clouds, mist, and rain to show off how pretty the sky is.
 * Half-Life's Xen. For all it was slated for having poor playability, arriving there and realising you're on a rock island suspended in some sort of nebula extending all the way below the horizon with no ground below you, just more startlingly alien sky... it's a pretty cool moment.
 * Borderlands has planet Pandora, whos moon isn't exactly round.
 * Final Fantasy IV follows the "one normal moon like Earth's, one special plot-related moon you get to visit" pattern.
 * The game confirms that
 * The world of Final Fantasy VIII has a fairly normal blue sky with one moon... except that the moon is enormous, taking up at least a quarter of the sky in most of the backdrop images. It is also, as the characters learn during the third disc, covered with monsters, and the "Lunar Cry" which carries those monsters to the planet below causes the planet-facing side of the moon to temporarily sport a huge blood-red spot with a milky white center that makes it look like a giant alien eye.
 * In The Legend of Zelda Majoras Mask, an intimidating moon growing ever-larger in the sky serves as both a timepiece and to remind players that (despite widespread recycling of character models) they're in the parallel world of Termina, not in Hyrule. Additionally, as the moon nears collision, the sky turns a sickly green during the day and reddish during the night.
 * Likewise, the Sacred Realm is said to have a gold-colored sky. It is blood-red by the events of A Link to the Past.
 * In Twilight Princess, the Twilight version of Hyrule has a yellowy brown sky, and there are black squares floating upwards. In the "real" Twilight Realm, the sky (such as it is) is swirling black, blue and purple.
 * Grandia II has a moon similar to ours, and a smaller red one -- Valmar's Moon.
 * Jak and Daxter: the unnamed planet has three celestial bodies: a sun, a moon, and a green, glowing planet that is out independent of day and night.
 * The titular Halo of the game series has a sky that looks like a normal Earth sky....except that you can see the horizon curling up and narrowing in the distance, stretching up above you, and coming back down around to the other side.
 * When you reach in Halo 3, the sky is blue but stars are visible. The Milky Way itself dominates the skyline.
 * The world of Wild Arms contains two moons. The usual boring old moon, and the new moon Malduke.
 * The skies of Brutal Legend are a tribute to Frank Frazetta, in which they shift all kinds of brilliant colors, and are never a clear blue. At night, brilliant stars and nebulae in the shape of skulls light up the night. It is inspired from the work of Frank Frazetta.
 * Doom features several variations on a red sky for Fire and Brimstone Hell. One sky is even made out of screaming, grimacing faces.
 * It gets better: One sky from an official MegaWAD is made out of what looks like twisted flesh.
 * Mass Effect. One of the few things that was unique about the otherwise cookie-cutter secondary planets were the sometimes awesome exotic skies. This is particularly true with moons.
 * Some explorable areas had skies that contained enormous planets and moons (which could actually get a little creepy, if only because the player would not be used to seeing things like this) ... which can make one wonder why the gravity on these planets isn't completely impossible to deal with.
 * In the second game it's suggested that mass effect fields were commonly used by visitors to compensate for different gravity levels among worlds.
 * One planet in the first game orbited a dying star, and was rather close. On the planet itself, this star dominated the sky. You could actually watch the surface of this alien sun boiling with it's own heat. --Awesome.
 * Na Pali, the planet where Unreal takes place, has two suns and two moons, which lead to some interesting landscapes and light effects. Unreal 2: The Awakening has some skies being almost completely dominated by other planets and their rings.
 * Although it was never seen on screen, the manual of Tass Times in Tonetown (a game mostly set in a Totally Radical dimension) mentions a triangular moon.
 * World of Warcraft has Alien Skies all over the place. Often, merely walking from one zone into the next is enough to turn the sky a completely different color (ostensibly it's always an effect of smoke or haze or the like, but it's far more dramatic than this could account for). The skies of Outland are even more exotic (and utterly gorgeous), full of an effect akin to a particularly dramatic aurora.
 * The aurora-like things you see in Outland are actually parts of the Twisting Nether that is bleeding physical world after Draenor was ripped apart by opening too many portals to the Nether. The Netherstorm zone is a result of an extreme version of this process.
 * Azeroth used to have two moons, but the smaller one disappeared in a patch that introduced weather effects. It's still mentioned in the background, tho.
 * The entire Marathon trilogy counts, every time you get to go outside. Especially on the planet L'howon, where most of the second and third games take place.
 * In Quake the sky was filled with ominous purple clouds; in Quake II the sky of the alien planet Stroggos was reddish-orange and sometimes had orbiting asteroids visible.
 * Spore's space stage allows you "Atmospheric coloring tools", which let you dye the skies of various planets.
 * In addition to planets that simply have strange skies by default. In addition to unusual colors, low-atmosphere planets have black starry skies and unusual features like binary stars, rings, or nearby gas giants can also be seen from the ground.
 * Heavily utilized in the Myst/Uru series of games, to distinguish Ages located on different planets.
 * In Fable I, the moon takes up a fifth of the sky, even during daytime.
 * The Homeworld game has coloured space(s); in imitation of the art of Chris Foss, often seen on paperback covers of the seventies and eighties. Ship design and colours, too.
 * In Team Fortress 2, the map Ctf_Doublecross originally had seven moons. Although one could write this off as a glitch or a mistake due it being nixed in a later update.
 * In Deadly Premonition, the sky turns weird every time there are enemies around.
 * In Metroid Prime 2: Echoes Dark Aether naturally has a purple or reddish sky, and in Light Aether, around the Temple Grounds, the sky will occasionally become unstable and shift between normal and a deep purple color.
 * In Metroid Prime 3: Corruption, the planet Bryyo does not rotate, so one half of the planet is stuck in perpetual daylight, and the other is stuck in perpetual night. The area Samus explores is where the two hemispheres meet and the sky there is in a permanent state of sunset.
 * In The Legend of Spyro, the world has two moons. This also plays a large role in the second game where its revealed that.
 * Red Faction: Guerrilla takes place on Mars, so yellow-orange sky is pretty understandable. There is also an oddly-shaped object in the sky that looks definitely out of place unless one knows that Phobos and Deimos actually have highly irregular forms.
 * According to this article, both moons can be seen from the Martian surface by the naked eye (Phobos even causes partial eclipses) but Deimos is too small and faint to be identified as non-circular. Therefore, the object in question is probably Phobos.
 * Quite a few galaxies from the Super Mario Galaxy games have these. Super Mario Galaxy 2 reveals that the Mushroom World has six large moons, along with the hundreds of smaller ones that serve as galaxies.
 * The Sky of Lennus in Paladins Quest is mostly normal, save for having multiple large purple moons. The flora, fauna, and overall terrain is far more alien.

Webcomics

 * Broken Space features Veldin, a world with an electric yellow sky, made all the more shocking for the protagonist because his home lacks a visible sky.
 * Tales of the Questor has two moons in the sky, one of which is twice the apparent diameter of the other, and which have 7 and 28 day orbits (a 13 month year, with 4 weeks to a month exactly. You can literally tell what day of the week it is by the phases of the moons.)
 * Slightly Damned has hell with a featureless sky that gets bright or dark instantly. Medius itself has a red moon and green moon.
 * Pibgorn Where the ghost throws Dru.
 * And the give away in the computer game
 * Smoke comics (a sub comic of WTF Comics) shows the sky as an indication smoke isn't on earth any more.

Web Original

 * Many of the planetscape wallpapers at Digital Blasphemy qualify.
 * Felarya has this trope, with a slight twist. The world is a dimensional plane which randomly connects to a sun, switching suns at, it seems, equally random intervals. Denizens wake up now and then to find a different sun in the sky - and a different night sky once the sun goes down.
 * This video shows what Earth's sky would look like from various locations if a scale replica of Saturn's rings was placed in orbit around our planet.
 * Here's an article from the Orions Arm encyclopedia that makes detailed predictions of what conditions would produce what sort of Alien Sky.
 * Land Games: Dark green at night, pale yellow during the day.
 * Homestuck: Alternia has two moons (third panel on the linked page), one large and green, one small and pink which has its own little natural satellite. Its sun is also large, red, and invariably described as blistering. Then you have the various Lands inside the game incipispheres:
 * Land of Wind and Shade: While the sky is blue and the near-omnipresent cloud cover is gray, said cloud cover is filled with fireflies.
 * Land of Light and Rain: While the sky is blue, the clouds (and the eponymous rain) flash colourfully.
 * Land of Heat and Clockwork: The sky is simply black and featureless.
 * Land of Frost and : The sky seems normal... Except there are auroras everywhere!
 * Land of Pulse and Haze: The sky is red, the clouds are purple, and there is a constant gray mist.
 * Land of Thought and Flow: The sky and the giant neurons that populate it are all various shades of teal.
 * Land of Quartz and Melody: The sky is purple, and there appears to be a glowing ring around the planet.
 * Land of Sand and Zephyr: The sky is yellow, and yellow-tinted wind swirls constantly.
 * Land of Brains and Fire: The sky is brown.
 * Land of Little Cubes and Tea: Both the sky and clouds are yellow.
 * Land of Rays and : The sky itself is a featureless black, but the rays probably afford an amazing skyscape when viewed from the ground.
 * Land of Maps and Treasure: The sky is a hodgepodge of maps, with brightly-coloured compass roses.
 * Land of Caves and Silence: The sky is black and featureless.
 * Land of Tents and Mirth: The sky has a glow in various shades of brown, dark yellow, and dark green.
 * Land of Wrath and Angels: The sky is an all-consuming, oppressive white glow.
 * Land of Dew and Glass: The sky has all this fluorescent, spiral shell stuff everywhere.
 * The world of Vytal in RWBY has two moons, one of which is shattered.

Western Animation

 * The planets Foodcourtia and Conventia in Invader Zim seem to all share a magenta-like sky. Hobo 13 has a yellow one, and others have a mostly transparent atmosphere. The stylization is truly apparent when Earth has a hideous red sky during the day, and the only time it looks normal is during a snowstorm.
 * Thundarr the Barbarian actually had a plot-related reason for its Alien Sky: The moon was broken in half by a "runaway planet" passing between the Earth and the moon, plunging the world into a new dark age. This gave many tropers copious amounts of Nightmare Fuel in their youth, especially as the show indicated it would happen in the far-off year of 1994.
 * The planet in Beast Wars had two moons. But, of course, one wasn't really a moon, revealed as part of the Planet of the Apes Ending of the first season.
 * The Futurama episode "My Three Suns" took place, appropriately, on a planet with three suns, one of which stretched from horizon to horizon. The humans and robot had no problems functioning there, though it was Death-Valley-level hot. In the Alternate Universe episode "The Farnsworth Parabox", the second universe has a psychedelic-colored sky. Amusingly, later in the Alternate Universe episode there's a shot of the (alternate) Earth from space, and it shows that the weird psychedelic sky is only a small patch over New New York. The rest of the planet looks normal, which indicates that it's probably Farnsworth's fault as all differences between the two universes were caused by coin-flips going one way instead of the other. That must have been some coin-flip...
 * Most Filmation shows set in outer space have planets with green skies.
 * An interesting variant in Superman the Animated Series. It's a cloudy day, and Luminous taunts Superman, saying he can bring Superman to normal human levels. Indeed, Superman has been getting weaker and weaker. Finally Superman goes outside city limits to punch rocks and the clouds break. And that's when it hits him... the sun is RED.
 * Visionaries The alignment of Prysmos's triple suns acts as a catalyst for the Age of Magic/Science. They are often seen throughout in the background of the series.
 * Oban Star Racers. If you're actually paying attention to the sky.
 * In the Justice League multi-part episode "Hereafter", Superman
 * This is later revealed to be the work of
 * Miseryville on Jimmy Two-Shoes has three suns. "Rocket Jimmy" revealed that there are multiple moons as well.
 * Xyber 9 New Dawn has Terrana, which has two moons, with both usually visible in the night sky at the same time.
 * In the last few seasons of Teenage Mutant Ninja Turtles, the sky is red instead of its normal blue. This wasn't actually done by an alien but rather to convey the relatively more serious tone of those seasons.
 * Thundercats 2011 has Third Earth, which orbits a gas giant with a great spot visible on its surface. Two moons are also visible.

Real Life

 * Many real-life planets have skies that look very different from Earth's. Mars, for instance, normally has a tan-gray sky and two tiny moons. Weather does affect it; a violet sky has also been photographed. Venus is enveloped entirely in yellow-brown clouds, which don't change. Furthermore, there are many differently-colored stars in the universe that have planets orbiting them, meaning that those planets do indeed have differently-colored suns. That, in turn, means that not only are atmospheres different, they are differently highlighted, which widens the variety of dayglow hues.
 * That without including the effects of stellar evolution -from a sun that looks not very different of the ours to a huge, red, one when the star becomes a red giant, and finally just a very bright star when the star has become a white dwarf-, or where's located the planet -just imagine, for example, the view of the Milky Way from the Magellanic Clouds or the star-studded sky of a planet in a globular star cluster.
 * The Earth also have vastly different skies. The Moon has a perpetual black sky, due to lacking an atmosphere. The same effect can also be seen at high enough altitudes on Earth. Titan (the largest moon of Saturn) has a dark tan-orange sky, due to its thick atmosphere, and so lacks a view of Saturn.
 * Also, Earth's moon is tidally locked, so from any one place in the "light side" the Earth barely moves in the sky. It just hangs there rotating on its axis and waxes and wanes depending on the time of the month i.e. the phase of the moon/earth. The sun would likewise rise every 28 days.
 * Actually the color of the sky is because of the particles in the air scattering the colors in the light spectrum from the sun/star, blue-violet is scattered and reflected back into our eyes giving the look that the sky is blue, and the sun is yellow because the other colors of light made it through the particles without completely scattering. This is because of frequencies and wavelengths, the specifics sounds utterly ridiculous so it's better if you don't know. Interesting Trivia: If our sky had enough particles to scatter most of the spectrum light from the sun while letting the rays through the sky would look white and the sun an extremely deep dark shade of red.
 * Occasionally one has such experiences on Earth, too. Ever wake up in a dust storm? When the millions of residents of Sydney, Australia woke up on 23rd September 2009 to a completely opaque red sky, there seemed to be only two things they could describe it as, neither of which any of them had experienced: The Apocalypse, or Mars.
 * Big enough volcanic eruptions can change the coloration of the sky over the places where the dust travels. The Krakatoa eruption is said to have given a green hue to the sun.
 * Not to mention when changes in barometric pressure (such as before a tornado) turn the sky green or orange, which can look very strange, especially to people who aren't used to that sort of thing.
 * A more common occurrence would be the occasional hunter's moon in which the moon appears red.
 * The Aurora Borealis, better known as Northern Lights (Aurora Australis if you're on the South Hemisphere) which are caused by the effect of certain solar particles on Earth's magnetic field, can look like someone was having fun finger-painting the sky.
 * Excessive light pollution on Earth at night, especially on cloudy nights, can produce a yellow sky.
 * Don't forget the skies of some planets that could fall into the category of Scenery Porn. Imagine, for example, how would be to see Saturn's rings from the planet itself, with them stretching from one side of the sky to the other like a huge rainbow (albeit with different colors, of course). Or the skies of Jupiter, with its moons (although only Io would appear larguer than the ours).