History Main / CometOfDoom

* ''Literature/WingsOfFire'': A comet appears in the sky during the last third of ''The Brightest Night''. It's large enough to be mistaken for a [[AlienSky fourth moon]] by the dragons of Pyrrhia, and it passes close enough to affect weather patterns and tides and to cause earthquakes. Though, given that the comet's passing coincides with a peace summit ending a twenty-year three-way war, and that it being in the sky creates the illusion of three full moons (known in-story as a [[TitleDrop "brightest night"]]) which for in-story prophecy reasons is highly auspicious, this trope is seemingly averted or inverted. [[spoiler: And then we find out that the earthquakes caused by the comet's passing snapped the enchanted bracelet keeping The Darkstalker [[SealedCanOfEvil asleep underground]]...]]

* ''Series/TheLordOfTheRingsTheRingsOfPower'': The meteor that falls at the end of the first episodes, which hides one of the Istari inside, is mistaken for a falling star or a comet, and everyone interprets it differently. The Harfoots believe is a bad omen, The mages from Rhun mistakes for the coming of Sauron, and the Elves believe is a SignAfTheEndTimes. Most of the characters are right to link the falling meteor to a possible future distasters, because the Istar was sent on Middle-earth by the Valar themselves now that evil regained its strength.

* ''Videogame/Wizard101'' released some content in [[MayanDoomsday late 2012]] where a comet is threatening to destroy a {{Mayincatec}} FantasyCounterpartCulture, populated by [[EverythingsBetterWithDinosaurs dinosaur]] [[BeastMan men]].

* ''Creator/ParadoxInteractive'':
** ''VideoGame/EuropaUniversalis'': A random event involves a comet or meteor appearing and the superstitious peasants being concerned enough that your country loses stability. Players complained that the event only had one option, so in each major update the devs added a new option... which also reduced stability.
** ''VideoGame/HeartsOfIronIV'': Parodied with the "[[https://en.wikipedia.org/wiki/Messerschmitt_Me_163_Komet Komet]] Sighted" event.
** ''VideoGame/{{Stellaris}}'': The "Comet Sighted" event returns, and your empire will interpret it as a good or bad omen based on their ethics. Hive Mind, Pacifist, and Xenophile empires gain unity; Egalitarian, Militarist, and Spiritualist empires gain happiness; and Authoritarian and Xenophobe empires lose happiness. Materialist and Machine empires, however, don't see any particular meaning in a hunk of icy rock so they'll shrug and go about their business.
** ''VideoGame/VictoriaAnEmpireUnderTheSun'' has a Comet Sighted event, but, because it's set in [[OutgrownSuchSillySuperstitions more enlightened times]], the comet gives you research points instead.

Before people had telescopes, comets were frightening objects of awe and wonder that seemed to appear out of nowhere, blazed brightly in the sky, then vanished as quickly as they came. OlderThanDirt, the "[[TheStarsAreGoingOut falling stars]]" mentioned in ''Literature/TheEpicOfGilgamesh'' were possibly a reference to comets or meteor showers. For thousands (and perhaps tens of thousands) of years, they were seen by civilizations around the world as omens of good and ill, pronouncing the deaths of kings, horrible disasters, and military victories. Western civilizations have generally categorized them as harbingers of evil,[[note]]The word '''disaster''' comes from Greek words ''dis'' (bad, evil) and ''aster'' (star).[[/note]] but the universal consensus is that when a comet appears, something momentous is happening, enough so that the heavens themselves have taken notice.

* The GrandFinale of ''Anime/SamuraiPizzaCats'' involves one of these. Initially it was supposed to harmlessly pass by the planet but [[spoiler:since he was fired from his position, the [[BigBad Big Cheese]] decides to drop it on the city. Naturally the Pizza Cats take care of it but unlike most episodes in the series, this episode plays the situation very seriously]].
* In ''Anime/SpaceCarrierBlueNoah'', the aliens rain down surveillance cameras disguised as meteors onto planet Earth, to scope out whether the planet is worth invading.
* ''Anime/YourName'' starts with news reports about the passing of Comet Tiamat. This is why the film turns from comedy to drama at the half-way point.
* In ''Anime/YuGiOhGX'', such a comet indicates the imminent [[spoiler: fulfillment of Jim Cook's prophecy]]. For bonus points, it appears to ''turn'' and fly straight towards [[spoiler:him]] several times, causing alarm, though [[spoiler: this is only an illusion, albeit part of the prophecy, and the comet is never the real threat.]]

* ''ComicBook/MyLittlePonyFriendshipIsMagicIDW'': The Secretariat Comet will be passing the Horsehead Nebula in [[RuleOfThree three]] [[RaceAgainstTheClock days]], an astronomical event said to effect every magical being in Equestria.

* The Red Comet in ''FanFic/PurpleDays''. [[spoiler:Its passing over Westeros triggers the beginning of the Long Night, giving Joffrey an estimate of how long he has to prepare.]]
* ''Fanfic/AnEmpireOfIceAndFire'' has the Great Fall, a magical comet that passes Planetos every 8000 years. Last time around, the Children of the Forest channeled its power to create the Night King, but in the process accidentally tore a chunk of the comet free and caused it to hit the planet, causing the Long Night. [[spoiler: When it passes again in the present, the Night King intentionally tears off another piece, bringing about a second Long Night.]]

* ''Film/{{Lifeforce}}''. The arrival of Halley's Comet foretells doom for London, as it contains an alien spaceship that carried space vampires. [[DiscussedTrope Discussed]], as the characters mention that the appearance of Halley's Comet has been considered a warning of disaster for centuries, possibly because seeing it meant the alien ship within was near enough to allow the vampires to reach Earth and feed.
* ''Film/NightOfTheComet''. A comet is due to appear in the night sky, and this comet is such a rare event that it becomes a massive celebration for its very rare appearance. (With an orbit of 65 million years, it was last seen over Earth when the dinosaurs died out. [[SarcasmMode A coincidence, surely]].) As its trail sweeps across the Earth, anybody directly exposed to it, meaning almost the entire human race, [[ApocalypseHow is reduced to red dust]]; anybody who suffers indirect exposure becomes a homicidal, slowly-dying zombie. A small handful of survivors were people who managed to shelter themselves away from exposure.
* The romantic comedy ''Film/{{Wimbledon}}'' actually has this: Creator/PaulBettany's character seems to take on l33t tennis skills only while a comet is in the sky. And yes, he wins UsefulNotes/{{Wimbledon}}, because everyone knows it will take the intervention of God for an Englishman to ever win that tournament again.
* In ''The Brainiac'', a comet carries a magician who escaped execution by transporting himself there and who then returns to earth 300 years later as a monster with forked tongue which he uses to suck peoples brains out.
* ''Film/{{Dragonheart}}: A New Beginning'' features a prophecy where an ancient evil will take hold of the land using a dragon's heart when a two-tailed comet blazes across the sky.
* Used in ''Film/DeepImpact'', justifiable as the comet is set to impact Earth and bring another Extinction-Level Event.
* In ''Film/EndOfDays'' the appearance of a comet above the full moon known as "The Eye of God" by Vatican astronomers, and it's the sign of the prophesied birth of the woman that will give birth to the anti-Christ.
* The film ''Film/{{Coherence}}'' features a reality-altering comet that creates (a possibly infinite number of) alternate continuities of a dinner party. The protagonists are forced to contend with their doppelgangers and soon find it difficult to distinguish one reality from another.

* In Creator/LarryNiven's novel ''Literature/LucifersHammer'', pieces of a comet slam into the Earth and destroy civilization.
* Ditto the book ''Comet Dis'Aster'', by L. Eduardo Vega, a book that incidentally has a lot of terror spread about it.
* In Creator/TadWilliams' ''Literature/MemorySorrowAndThorn'' trilogy, the Conqueror Star is a highly visible comet whose coming is said to portend the fall of empires. Given the limited amount of information presented in the story itself, it's hard to say whether it actually has supernatural powers, but its periodicity is certainly very odd.
* The Red Star in ''Literature/DragonridersOfPern'' is a captured planet in an elongated (comet-like) orbit. When you can see it in the sky, it means that it's nearby... and has dragged a bunch of frozen organisms from the Oort Cloud to the inner solar system with it. These organisms, upon entering Pern's atmosphere, become the Threads. They eat any organic material they can. Crops, wood, grass, fungi... people...
* In one ''Literature/{{Animorphs}}'' book the characters have traveled to the time of the dinosaurs and see a comet in the sky. Cassie mentions that humans used to believe that comets were a bad omen, and Ax says that Andalites had a similar superstition. Of course, said comet turns out to be [[TheCretaceousIsAlwaysDoomed the comet that killed the dinosaurs]].
* A comet pops up during the siege of a town in ''Literature/ColasBreugnon'', and is taken to be a bad omen, though no one can agree on what it is an omen of or to whom it is bad.
* In ''Literature/TheBlackCompany'' books, a Comet shows up twice in the story and once in the backstory, each time to portend the [[TheChosenOne White]] [[AntiMagic Rose]] coming to battle the [[EvilSorceror forces of]] [[ImplacableMan the]] [[BigBad Dominator]]. This leads to a shocking twist in book 3; [[spoiler:by that point everyone knows the major points of the centuries-long war are linked to the comet's cycle, but the final battle flares up decades early. The dammed comet shows up anyway.]]
* The very old story, ''Literature/HectorServadac'', has the titular hero and several others accidentally travelling into space on pieces of the Earth ripped away by collision with a comet and having to survive while forming a plan to get back to Earth when the comet returns near it again. Somehow, nobody else on Earth notices anything. Crosses over with ScienceMarchesOn.
* Creator/GeorgeRRMartin's
** A red comet appears in the sky early in ''Literature/ASongOfIceAndFire'' series, marking the deaths of both King Robert Baratheon and the murder of Ned Stark. Unusually, the characters aren't universally filled with dread; several of them decide the comet shows divine favour for their side (Daenerys thinks it's a sign that will lead her khalasar to safety; the Lannisters believe it is a sign of good fortune for their family and especially Joffrey; etc.) At the end of ''A Feast for Crows'' it seems to be confirmed that [[spoiler:it's a part of the prophecy of the Prince Who Was Promised]], though in ''The Winds of Winter'', Euron Greyjoy claims that it is a sign of the end times. Unlike most cases, however, [[OmnicidalManiac he seems perfectly happy with this.]]
** Also used by Martin in "Literature/ThePlagueStar", one of his "[[Literature/TufVoyaging Haviland Tuf]]" stories (chronologically the first); the recurring "star" is actually a (''huge'') derelict starship automated to bombard a planet with bioweapons.
-->If this is found after the plague star has waned, as the night-hunters say it will, do not be deceived. This is no fair world, no world for life. Here is death, and plagues beyond numbering. The plague star will shine again.
* In ''Literature/TheLegendsongSaga'', the comet appears to be the Earth equivalent of the Unraveller, the sign that the balance between [[OrderVersusChaos Chaos and Harmony/Song]] is about to change.
* In ''Literature/WarAndPeace'', the Great Comet of 1811, still visible well into 1812, is taken as a harbinger of UsefulNotes/NapoleonBonaparte's invasion in June of that year.
* In Tove Jansson's ''[[Literature/TheMoomins Comet in Moominland]]'', the eponymous object comes very close to earth, causing quite a bit of upheaval, but in the end just misses the planet and goes zooming back into space.
* Creator/RaymondFJones's ''Literature/TheYearWhenStardustFell'', a 1958 sci-fi juvenile. Earth has been caught in the tail of a comet whose particles have caused all metal to bind together, leading to technological and social collapse.
* When reality starts getting ''really'' weird in ''Literature/TheColourOfMagic'', we're told that "In the cometary halo around the fabled Ice System of Zeret a noble comet died as a prince flamed across the sky."
* Creator/IsaacAsimov's ''Literature/WordsOfScienceAndTheHistoryBehindThem'': The entry for "Comet" explains the fear from ancient people that comets heralded disaster, and not until the 16th century were they able to be studied in enough detail to determine that they were further away than the moon. The first comet to have its orbit calculated is now called Halley's Comet, after the astronomer Edmund Halley who (in 1704) predicted its return around the year 1758 (the approximation is important as it returned in 1759).
* In ''The Alchymist's Cat'', a prequel to the ''Literature/DeptfordMice'' books, a comet signals the birth of Jupiter, who would go on to become the BigBad of the original trilogy.

* In ''Series/BabylonFive'', the Brakiri solar system contains only one comet with a period of 200 years. The comet is considered a death omen (and the focus of the season five episode "Day of the Dead"). As a result, the Brakiri don't even like comets to be ''mentioned''.
* In ''Series/{{Beauty and the Beast|1987}}'', a comet was blazing in the sky the night billionaire Elliot Burch is murdered by operatives of his rival, Gabriel. Father marks the occasion by quoting Shakespeare: "When beggars die there are no comets seen; The heavens themselves blaze forth the death of princes."

** In "[[Recap/DoctorWhoS19E4TheVisitation The Visitation]]", the Terilepils' ship is mistaken for a comet and taken as a harbinger of doom by the locals.
** In ''[[Recap/DoctorWhoS25E3SilverNemesis Silver Nemesis]]'' there is a comet with a period of 25 years that, according to the Doctor, really does bring misfortune: it's actually an alien superweapon that somehow (ahem) wound up in a solar orbit. He cites the the two World Wars and the assassination of JFK as the results of the last three times it came near Earth.
* ''Series/GameOfThrones'': Red comet during the Season 2 episode "The North Remembers" coincides with birth of dragons and return of Magic, though everyone interprets it differently.
* In the third episode of ''Series/CosmosASpacetimeOdyssey'', "When Knowledge Conquered Fear", UsefulNotes/NeilDegrasseTyson explains the origins of this trope and how it was based in superstition and ignorance of how the solar system worked. He goes on to tell an absolutely ''epic'' version of how Edmund Halley went about utterly crushing this superstition. It ended with Halley's "prophecy" that not only would one particular comet return in 50 years, but accurately and correctly predicting where in the sky it would appear, and how long it would be visible, and how "Halley's Comet" became the best known comet in the history of the world.
* ''Series/{{Benson}}'': The episode "Last Man on Earth" shows the passing of Halley's Comet causing almost everyone on Earth to dissolve, leaving only piles of clothes and dust (very much like ''Film/NightOfTheComet''). However the whole situation is AllJustADream.
* A non-supernatural variant occurs in the ''Series/StarTrekTheOriginalSeries'' episode "The Deadly Years" when radioactive particles in a comet's tail contaminate a planet and cause RapidAging.
* In the ''Series/StarTrekDeepSpaceNine'' episode "Destiny", a comet appears that Kira believes heralds the fulfillment of a prophecy that will result in the destruction of the wormhole.

* In a rare example of a comet being a ''good'' omen, some theologists believe that the [[Literature/TheBible Star of Bethlehem]] was one. Others discount this because of said stigma of comets being doom omens, instead assuming that the event (assuming it actually happened at all) was an alignment of several stars. Conversely, ''Literature/TheBookOfRevelation'' predicts a comet or other stellar object named Wormwood will hit the Earth, causing devastation, as part of the end times disasters.

* In the ''TabletopGame/DungeonsAndDragons'' adventure module ''X2 TabletopGame/CastleAmber'', the appearance of a blazing red comet over Averoigne causes an NPC to become a deadly monster.
** "King-Killer Star" of TabletopGame/ForgottenRealms. It ''did'' cause damage, and turned out to be [[spoiler:just a random comet with right period chosen as the trigger condition for a magical device -- until the latter was "hacked"]].
* In the ''TabletopGame/{{Shadowrun}}'' supplements ''The Year of the Comet'' and ''Wake of the Comet'', the passing of Halley's Comet in 2061 greatly increased the magic level on Earth, which caused SURGE (Sudden Recessive Gene Expression) mutations in (meta)humans, animals and plants, the re-appearance of the dragon Ghostwalker and natural disasters in the Asia that brought down the Japanese Empire.

** The presence of a twin-tailed comet is often seen as an omen to the people of The Empire, due to the legend that their founder Sigmar's birth was heralded by it's appearance. This is not always seen as a ''good'' omen, however, especially to the city of ''TabletopGame/{{Mordheim}}'', which was ''hit'' by one.

* In the Alliances expansion for TabletopGame/MagicTheGathering, General Varchild saw a comet which she believed meant that she was to conquer the barbarian tribes as a part of a manifest destiny for her people. So she took her army and began the slaughter.

* A comet appears in the sky after the assassination of Theatre/JuliusCaesar, in [[Creator/WilliamShakespeare Shakespeare's]] play of the same name.

* In ''VideoGame/UltimaV'', each of the Shadowlords has their own comet; if you have a telescope you can determine which city they're in by looking for where the comets are.
* ''VideoGame/FinalFantasyVII''. Though it's technically a meteor, and not so much an omen of TheEndOfTheWorldAsWeKnowIt as the cause of it.
** VideoGame/FinalFantasyV also has prophetic falling heavenly bodies, but they are used to help save the world instead of destroy it.
* ''VideoGame/SuperMarioGalaxy'' has the Prankster comets, which enable [[ChallengeRun Challenge Runs]] for certain levels.
* A random event in ''VideoGame/EuropaUniversalis'' involves a comet or meteor appearing and the superstitious peasants being concerned enough that your country loses stability. Players complained that the event only had one option, so in each major update the devs added a new option...which also reduced stability. ''[[VideoGame/VictoriaAnEmpireUnderTheSun Victoria 2]]'' also has a Comet Sighted event, but because it's set in [[OutgrownSuchSillySuperstitions more enlightened times]] the comet gives you research points instead.
** Having a Natural Scientist advisor makes the comet event actually beneficial for once.
** The "Comet Sighted" event returns in ''VideoGame/{{Stellaris}}'', and your empire will interpret it as a good or bad omen based on their ethics. Hive Mind, Pacifist, or Xenophile empires will gain unity; Egalitarian, Militarist, or Spiritualist empires gain happiness; and Authoritarian or Xenophobe empires lose happiness. Materialist or Machine empires, however, don't see any particular meaning in a hunk of icy rock so they'll shrug and go about their business.
** Parodied in ''VideoGame/HeartsOfIronIV'' with the "[[https://en.wikipedia.org/wiki/Messerschmitt_Me_163_Komet Komet]] Sighted" event.
* ''VideoGame/IllusionOfGaia's'' entire plot is influenced by a comet that returns every few hundred years. Each visit affects all life on Earth in unexpected ways, although the end results thus far (that tend to linger even until the next visitation) are usually the same (mutations, destroyed civilizations, famine, etc.).
* In the ''TabletopGame/CallOfCthulhu'' PC adventure game VideoGame/ShadowOfTheComet , the passing of Halley's Comet coincides with [[EldritchAbomination some truly creepy stuff going down]].
* A comet herald for the arrival of [[BigBad Balor]] in ''VideoGame/{{Myth}}''.
* ''VideoGame/GadgetPastAsFuture''. The player has to gather gizmos to build a spaceship before a comet hits some {{steampunk}}-ish, ''Literature/NineteenEightyFour''-esque eastern European nation.
* In ''VideoGame/ShadowTheHedgehog'', there is the Black Comet. Not an actual comet, however, but a meteoroid that serves as the vessel of [[BigBad Black Doom]] and his army. Black Doom uses the Chaos Emeralds to teleport it into the atmosphere and start sucking energy out of the planet. Fortunately, it turns out that the space colony A.R.K.'s [[KillSat Eclipse Cannon]] was created to [[Awesome/SonicTheHedgehog blow the Black Comet to smithereens. After Shadow teleports it back out into space.]]
* In ''VideoGame/BatenKaitos Origins'', Guillo's strongest special attack, Aphelion Dustwake, showers enemies with the ice trail of a comet. It's quite overpowered.
* In ''VideoGame/ChronoTrigger'', the "Red Star" that heralds the end of the dominance of the Reptites and beginning of the ascension of mankind as the dominant species is actually [[BigBad Lavos]], and he not only ''heralds'' [[ColonyDrop the change]], [[PhlebotinumKilledTheDinosaurs he causes it]].
* In ''VideoGame/{{SOMA}}'', the comet Telos completely scorched the Earth's surface on impact, leaving only the crew of the Pathos-II UnderwaterBase alive. [[spoiler: This prompted some of them to begin work on a machine called the ARK, that could hold a virtual world for human [[BrainUploading brain scans]] to inhabit.]] By the time you arrive, a year already passed since the comet's impact, and things have taken a [[LateToTheTragedy far greater turn for the worse]].
* In {{VideoGame/Strife}}, the plot is triggered (some time before the events of the game) by a comet striking the Earth. [[spoiler:The last levels reveal that the "comet" was almost certainly [[BigBad The Entity]]'s spaceship crash-landing -- probably deliberately.]]
* The ''VideoGame/MetroidPrimeTrilogy'' is all about this. ''VideoGame/MetroidPrime'' and ''VideoGame/MetroidPrime2Echoes'' are about saving the planet after the comet lands and starts mutating everything / creating an interdimensional rift. ''VideoGame/MetroidPrime3Corruption'' has 5: One in the intro sequence that requires you to activate an Anti-air cannon in time, three more that already landed and you're trying to fix, and the final one is inside the GeniusLoci planet that makes these to spread its influence.
* The third ''VideoGame/KillerEscape'' game reveals that [[spoiler: a dwarf star called "Nemesis" carrying tons of debris from the Oort cloud will strike the Earth as it passes through the solar system. Bonus content from the ''VideoGame/{{Icescape}}'' series also foreshadows this.]]
* In chapter 2 of ''VideoGame/TheWitcher2'' a comet is visible in the skies, even at daytime, this is during an endless spectral battle is taking place.
* One of these kicks off ''VideoGame/DiabloIII'', falling on Tristram Cathedral and blasting Deckard Cain into its depths, in addition to making the dead rise in its wake. The fallen star is mentioned as the first sign in the Prophecy of the End Days that the end has begun, and turns out to be [[spoiler:the archangel Tyrael, having fallen from Heaven because he's sick of being constrained by his angelic brethren from helping humanity against demonkind]].
* ''Videogame/Wizard101'' drove this thing into the ground by releasing some content in [[MayanDoomsday late 2012]] where a comet is threatening to destroy a {{Mayincatec}} FantasyCounterpartCulture, populated by [[EverythingsBetterWithDinosaurs Dinosaur]] [[BeastMan men]].
* The ShootEmUp ''Halley's Comet'' is about defending the solar system from aliens and comets spawned by the titular comet. Any aliens not destroyed (and occasionally, enemy fire) will collide with the planet being defended, and if any planet reaches 100% damage, it will cause a NonstandardGameOver. It was released in 1986, the same year it was last visible from the solar system.
* The ''VideoGame/DarkestDungeon'' DLC ''The Colour of Madness'' centers around a comet that crashed into a farmer's field. The Ancestor promptly swooped in and took over so he could investigate. As it turned out, [[spoiler:the comet contained an infant EldritchAbomination]], and its presence began to warp time in unnatural ways around the farm.

* In ''VideoGame/TotalWarWarhammerII'', the plot of the game's primary campaign begins with the appearance of the Twin-Tailed Comet, heralding the destabilization of the Great Vortex of Ulthuan -- a CosmicKeystone that protects the world from demonic invasion. The four playable races swiftly enact plans to fight for control of the Vortex's energies, either to protect the world or fuel a campaign of conquest. [[spoiler:The final act reveals that the Comet was an elaborate rocket-propelled hoax created by [[RatMen the Skaven]], who want the other races to fight and further destabilize the Vortex so they could use it to summon their god, [[EldritchAbomination the Great Horned Rat]], into the mortal plane.]]

* Happens at least one time in ''WesternAnimation/TheFairlyOddParents''. Of course, Timmy has wished for there to be no noise, and he cannot wish away the comet. Until he figures out that he can use charades ([[ChekhovsGun conveniently played in the early part of the episode]]) to wish for sound.
* This happened at least once in ''WesternAnimation/XiaolinShowdown''. A comet accompanies a mysterious event that could quite easily cause TheEndOfTheWorldAsWeKnowIt.
* In ''WesternAnimation/AvatarTheLastAirbender'', Sozin's Comet grazes the sky every 100 years to grant firebenders the ability to, well, shoot a lot more fire. A century before the series begins, it provided Fire Lord Sozin and his army the strength for a near all-encompassing genocide of the Air Nomads. The impending doom it will bring if [[BigBad Fire Lord Ozai]] is allowed to use it makes our heroes' mission much more urgent. Near the climax, [[spoiler:Ozai decides use it to burn the Earth Kingdom to the ground.]]
* ''Comet in Moominland''s main plot.
* ''WesternAnimation/TheSmurfs1981'' episode "The Comet Is Coming" is a story where the Smurfs think from a message that was torn in transit written by Papa Smurf that the night of a comet's appearance is their last night of living, and so they make preparations insofar as even [[Franchise/{{Superman}} creating a rocket that would send Baby Smurf off to another planet]].
* ''WesternAnimation/AdventureTime'': The Catalyst Comets, terrible events happen whenever they are near. [[spoiler:However, this is averted in "The Comet", where it is revealed Catalyst Comets are sentient, and are more of agents of change rather than malevolent forces.]]
** [[spoiler: Played straight in "Evergreen" with the Lich Comet, which is implied to [[PhlebotinumKilledTheDinosaurs be responsible for the extinction of the dinosaurs]].]]

** In the episode "Let's Play the Quest for the Wholly Gruel", [[UnwittingInstigatorOfDoom Stumpy unknowingly launches a comet onto the planet using a magical artifact.]] It's stopped just before it hits.
** In Episode 77, Kaeloo launches a comet onto the planet. [[spoiler: This time, the planet actually does get destroyed, but everyone survives ([[ResetButton and the planet is fine by the next episode]]).]]

--> "On the very days of my Games a comet was visible for seven days in the northern part of the sky. It was rising about an hour before sunset, and was a bright star visible from all lands." -- Caesar Augustus

* The [[https://en.wikipedia.org/wiki/Great_Comet_of_1811 Great Comet of 1811]] was visible during the first of the [[https://en.wikipedia.org/wiki/1811%E2%80%9312_New_Madrid_earthquakes New Madrid earthquakes]] that rocked six American states.
** Speaking of that comet, it was popularly thought to have portended Napoleon's invasion of Russia and the War of 1812, among other events.

* OlderThanDirt: Mentioned on ancient Chinese oracle bones from the late Shang dynasty. A comet was also among the omens thought to have foreboded the fall of the Shang dynasty by the victory of King Wu of Zhou over King Zhou of Shang, c. 1050 BCE.
** In modern times, comets are colloquially known as 掃把星 ("broom star"), which is also used to describe people who are TheJinx.

* [[UpToEleven Even Older Than The Older Dirt]]: A comet may have been involved in [[TheCretaceousIsAlwaysDoomed the most famous extinction event in prehistory]].
* [[Creator/CarlSagan Carl Sagan]] included a lot about the naming and mythology surrounding comets in different cultures in his 1985 book ''Comet'' (co-authored with Ann Druyan) and noted that Comets could be seen as portents of ''good'' depending on when they appeared. Most interestingly, he suggested that the Swastika symbol was the result of a comet appearing head-on to Earth so that the rotation of its jets of gas and dust were visible. The Swastika averted this for ages by being a symbol of ''good fortune'' in many cultures and religions, especially Hinduism (from where the name comes). It was also a symbol of good luck in Europe and North America all the way into the early 20th century [[UsefulNotes/NonNaziSwastika before its association with Nazism]] turned it into a symbol of evil and doom.

* In ''VideoGame/TotalWarWarhammerII'', the plot of the game's primary campaign begins with the appearance of the Twin-Tailed Comet, heralding the destabilization of the Great Vortex of Ulthuan -- a CosmicKeystone that protects the world from demonic invasion. The four playable races swiftly enact plans to fight for control of the Vortex's energies, either to protect the world or fuel a campaign of conquest. [[spoiler:The final act reveals that the Comet was an elaborate rocket-propelled hoax created by [[RatMan the Skaven]], who want the other races to fight and further destabilize the Vortex so they could use it to summon their god, [[EldritchAbomination the Great Horned Rat]], into the mortal plane.]]

* The film ''Film/{{Coherence}}'' features a reality-altering comet that creates (a possibly infinite number of) alternate continuities of a dinner party.

* ''Film/Coherence'' features a reality-altering comet that creates (a possibly infinite number of) alternate continuities of a dinner party.

* ''Film/Coherence'' features a reality-altering comet that creates (a possibly infinite number of) alternate continuities of a dinner party.

* [[Creator/CarlSagan Carl Sagan]] included a lot about the naming and mythology surrounding comets in different cultures in his 1985 book ''Comet'' (co-authored with Ann Druyan) and noted that Comets could be seen as portents of ''good'' depending on when they appeared. Most interestingly, he suggested that the Swastika symbol was the result of a comet appearing head-on to Earth so that the rotation of its jets of gas and dust were visible. The Swastika averted this for ages by being a symbol of ''good fortune'' in many cultures and religions, especially Hinduism (from where the name comes). It was also a symbol of good luck in Europe and North America all the way into the early 20th century [[NonNaziSwastika before its association with Nazism]] turned it into a symbol of evil and doom.

* [[Creator/CarlSagan Carl Sagan]] included a lot about the naming and mythology surrounding comets in different cultures in his 1985 book ''Comet'' (co-authored with Ann Druyan) and noted that Comets could be seen as portents of ''good'' depending on when they appeared. Most interestingly, he suggested that the Swastika symbol was the result of a comet appearing head-on to Earth so that the rotation of its jets of gas and dust were visible. The Swastika averted this for ages by being a symbol of ''good fortune'' in many cultures and religions, especially Hinduism (from where the name comes). It was also a symbol of good luck in Europe and North America all the way into the early 20th century before its association with Nazism turned it into a symbol of evil and doom.

* In a rare example of a comet being a ''good'' omen, some theologists believe that the [[Literature/TheBible Star of Bethlehem]] was one. Others discount this because of said stigma of comets being doom omens, instead assuming that the event (assuming it actually happened at all) was an alignment of several stars.

* Happens at least one time in ''WesternAnimation/TheFairlyOddparents''. Of course, Timmy has wished for there to be no noise, and he cannot wish away the comet. Until he figures out that he can use charades ([[ChekhovsGun conveniently played in the early part of the episode]]) to wish for sound.

-->-- '''Calpurnia''', ''Theatre/JuliusCaesar'' by Creator/WilliamShakespeare

* ''VideoGame/SuperMarioGalaxy'' has the Prankster comets, which act as [[ChallengeRun Challenge Runs]] for certain levels.

* ''VideoGame/SuperMarioGalaxy'' has the Prankster comets.

* In ''The Alchymist's Cat'', a prequel to the ''Series/DeptfordMice'' books, a comet signals the birth of Jupiter, who would go on to become the BigBad of the original trilogy.

* In the ''TabletopGame/DungeonsAndDragons'' adventure module ''X2 Castle Amber'', the appearance of a blazing red comet over Averoigne causes an NPC to become a deadly monster.

Before people had telescopes, comets were frightening objects of awe and wonder that seemed to appear out of nowhere, blazed brightly in the sky, then vanished as quickly as they came. OlderThanDirt, the "[[TheStarsAreGoingOut falling stars]]" mentioned in ''Literature/TheEpicOfGilgamesh'' were possibly a reference to comets or meteor showers. For thousands (and perhaps tens of thousands) of years, they were seen by civilizations around the world as omens of good and ill, pronouncing the deaths of kings, horrible disasters, and military victories. Western civilizations have generally categorized them as harbingers of evil, but the universal consensus is that when a comet appears, something momentous is happening, enough so that the heavens themselves have taken notice.