Science Marches On / Astronomy

Top: Mars as imagined in The Martian Chronicles.
Bottom: Mars as it actually is.

Astronomical examples of Science Marching On.

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The Moon

Outdated depictions of the Moon.

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Anime and Manga

• Osamu Tezuka did a couple of Astro Boy stories featuring the title character visiting the Moon in the 1950s. One of which featured the Moon having a breathable atmosphere in the daytime that froze solid when the Moon was facing away from the Sun. Tezuka admitted in one of his introduction comics that he just pulled it out of his ass because he thought it would make a good story. In the TV series the story was set on an asteroid, which makes even less sense. Another story featured a deposed Russian aristocrat trying to conquer the Moon because it was rich in diamonds created by the heat and pressure of the countless meteorite impacts that have blasted its surface. This was based on an actual scientific theory of the time, which is briefly summarized in the manga itself.

Film

• The opening narration of Forbidden Planet, which was released in 1956, predicted that humans wouldn't land on the Moon until the end of the 21st century. The first manned landing on the Moon happened a little over 12 years later.
• In A Trip to the Moon, the "astronauts" discover a Moon populated by giant mushrooms and weird little people that explode when you whack them with an umbrella. Of course, George Melies was a magician who was not particularly interested in scientific accuracy.

Literature

• In 2001: A Space Odyssey, it's stated that samples of Moon rock and dust apparently proved that the Moon was never part of Earth. In fact, real world Moon samples provided proof that the opposite was true.
• Arthur C. Clarke's novel A Fall of Moondust assumed that the alternate heating and cooling of the dust on the Moon, due to the stark contrast between lunar daylight and lunar night, would eventually result in a miles-thick layer of dust so fine it acted like a liquid. The actual lunar dust that the Apollo astronauts observed was only a few inches thick, and indeed behaved more like dust. While Moon dust indeed turned out as fine as predicted, Clarke failed to consider the vacuum cementing that occurs between particles of the dust in the airless environment of the Moon. Even the slightest pressure causes the particles to fuse together into a dense and stable structure, making it to behave like any other dust. Further, the effects of weathering are diminished on the Moon due to the lack of air and water, so the particles of dust on the Moon are jagged and irregular (on Earth, any such particles would become smooth and rounded over time), allowing them to lock together far better than, say, sand on Earth (which is also why the footprints left by the astronauts are so clear).
• In The First Men in the Moon, the Moon actually has air and food, and is actually richer in oxygen than Earth.
• In Robert A. Heinlein's "The Man Who Sold The Moon", the first manned expedition to the Moon discovers uranium and diamonds. Heinlein also made several wrong predictions regarding human exploration of the Moon. In an introduction to the short story collection featuring "The Man Who Sold The Moon", Heinlein stated he would be very surprised if men walked on the Moon before the end of the 20th Century. He must have been very pleasantly surprised on July 20th, 1969. He didn't seem to have any compunctions about writing stories involving men landing on the Moon earlier, however, as The Moon Is a Harsh Mistress mentions that the Moon first became a colony sometime in the 1980s. Of course, the former was written in 1949; the latter in 1966.
• In one of the rare humorous short stories written by Edgar Allan Poe, the main character proves a theory of his that there is no vacuum of space, the atmosphere just gets so thin that air pumps are needed to pressurize a hot air balloon so he can breathe during his trip to the Moon. Arguably averted by the ending which very heavily implies that he was lying his ass off the entire time.
• Rocket Ship Galileo, Heinlein's first novel, has a secret Nazi base on the moon immediately after World War II!
• The French series San Antonio had a book (written in the 60s) where the MacGuffin is a series of photographs that don't seem to represent anything. Until the epilogue, where we learn that, by putting a camera into a rocket and attaching a special retrieval system, you could (gasp!) obtain increasingly detailed photographs of any location on earth!
• Discussed in Kim Newman's Diogenes Club story "Moon Moon Moon". In 1969, some fanatical members of a group of occultists who have explored the fantasised version of the Moon that exists in the human collective subconscious attempt to sabotage the Moon Landing, because they believe that it will erase it by proving the Moon to be lifeless.

Mercury

Outdated depictions of Mercury.

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• The Other Wiki puts "Old Mercury" and "New Mercury" in separate sections on their "Mercury in fiction" page. The dividing line is 1965, when astronomers showed using radar observations that Mercury was not tidally locked to the Sun as previously believed, but actually rotates 3 times per 2 local years (for a sidereal day of 58.7 Earth days, and a solar day of about 176 Earth days).

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• Isaac Asimov:
  • "The Dying Night": Written in 1956, and Mercury being tidally locked is a plot point. In one reprint Asimov includes a very tongue-in-cheek note^note This is the man who wrote the essay "The Relativity of Wrong", after all saying scientists should get things right in the first place, and he's not going to change his plot over their whims.
  • Lucky Starr and the Big Sun of Mercury: Written in 1955. A preface added to the novels in The '70s, talks about radar-beam reflections from the surface of Mercury in 1965, proving that Mercury rotates on its axis every 59 days.
  • "Runaround" (written in 1942) still works, but the operation wouldn't be called "Sunside".
• Hal Clement's Iceworld features a gang of alien drug dealers who set up their base camp in a valley on Mercury's surface facing the sun, and line the valley with mirrors to reflect enough light into the base to make it reasonably warm. Iceworld was published in 1953, twelve years before they realized Mercury was not tidally locked.
• Larry Niven used the same obsolete Mercury data in his first published story, "The Coldest Place". He offered to pull it when scientists inconveniently announced this discovery just after he mailed the story to the publisher. The story was published anyway, as it was correct at the time it was written. The story "Becalmed in Hell", written the following year, tells essentially the same story but set on Venus with incredibly high temperatures rather than on an incredibly cold dark side of Mercury. Nevertheless, in the collection Three Books of Known Space, Niven says "these stories are part of the fabric of Known Space ... Mercury rotates once per solar orbit - in Known Space, but not in the real universe!"
• According to Ray Cummings in Tama of the Light Country, Mercury has an atmosphere and several civilizations, and the American astronaut (something of a Mighty Whitey) who tells the story was trying to get to the Moon, but overshot.
• Clark Ashton Smith's short story "The Immortals of Mercury" describes the planet as tidally locked and inhabited by insufferable Space Elves in vast climate-controlled underground colonies. Coincidentally, the scientific belief that Mercury was tidally locked was refuted the year after the story's publication.
• A previously held position about Mercury recognised that the side perpetually facing the Sun would be a boiling Hell far too hot to support life, whereas the side perpetually facing away from the sun would be as cold and frozen as the Seventh Circle of Hell. Much speculation was made in both scientific and science-fiction circles about the boundary zone between light and dark being - potentially - capable of sustaining life and if so what life might be found there. Much ink was spilt concerning the Temperate Zone of Mercury. This lasted until closer observation revealed that this planet also turns on its axis. Very slowly. But no life would ever have a chance to colonise the Twilight Belt before it either froze or fried.

Venus

Outdated depictions of Venus.
Additional examples can be found in the Sub-Trope Venus Is Wet.

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Literature

• Any number of stories have Venus being Terrestrial-habitable (usually a jungle, swamp or ocean planet, as the cloud-covered sky suggested high humidity). This is particularly relevant because Venus is closer to the Earth than Mars, and if it were even as habitable as Mars really is, would probably be the main target of our current plans for trans-Lunar interplanetary flight. Instead, as we now know, Venus is the least habitable terrestrial planet — even Mercury is a friendlier environment!
  • For starters, there's its mean surface temperature of 462 degrees Celsius (about 864 degrees Fahrenheit). Then we have the 91 atmospheres of air pressure. Do you want to be cooked to death or crushed to death?
  • Also, there's the constant hurricane-speed winds and sulphuric acid rain to worry about.
  • The result of this is writers playing around with the idea of terraforming Venus, as in Arthur C Clarke's 3001, the final book in the series that started with 2001: A Space Odyssey (itself a great example of this trope). Terraforming a hostile Venus is far from a new idea in science fiction, actually; the idea is central to Pohl’s The Space Merchants, published in 1952. The technical issues may be worse than once thought, though; getting rid of all the excess atmosphere would be an interesting job, just for a start.
  • Interestingly, astronomers now believe that Venus did have the kind of atmosphere that is described in the habitable Venus stories — two billion years ago. Whether it actually had any sort of life is another story, of course.
• In-universe in Carl Sagan's Contact, Ellie Arroway spends her childhood thinking there are crystal castles on Venus, but when probes reveal the true harsh environment she imagines them melting away.
• Robert A. Heinlein indulges in a swampy jungle Venus in Between Planets, Podkayne of Mars and Space Cadet.
• Ray Bradbury's short story The Long Rain correctly assumed that Venus has an environment that is uninhabitable for human life... except he claimed it was because of the climate consisting of constant precipitation (and occasional electric storms) which could very easily drive any person mad from being on the surface for an extended period of time. Don't worry though, because there's these special "Sun-Domes" that you can live in on the planet with an artificial sun and plenty of food and warmth. That last part becomes somewhat Hilarious in Hindsight when you consider that not even the probes can survive for long on Venus and it's supposedly hot enough to melt lead, meaning that even if you could somehow get multiple structures down there and find a way to avoid being incinerated by the sulfuric atmosphere, warmth would probably be the last thing on your mind.
  • Another Bradbury short story "All Summer in a Day" is about humans colonizing Venus (contrary to the previous example) who only get one hour of sun every seven years. This story was written under the assumption that Venus's atmosphere had liquid water, instead of lethally corrosive sulfuric acid.
• Perry Rhodan has Venus as a thriving jungle planet as do Edgar Rice Burroughs' Carson Napier stories.
• The Space Trilogy: Perelandra, the sequel to Out of The Silent Planet mentioned below, does this. Its Venus is a paradise ocean world, with most of the "land" being floating mats of plants and actual solid islands being very rare.

Live-Action TV

• One scene in Disney's Mars and Beyond was about the other planets in our Solar System, and when we focus on Venus, the narrator says "There may be life on Venus...", but that film was made five years before Mariner 2 discovered that Venus is actually too hot to support life.

Mars

Outdated depictions of Mars. Additional examples can be found in the subtrope Once-Green Mars.

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Comic Books

• Current versions of the DC Comics character the Martian Manhunter establish that he was brought to Earth from the distant past, when it's just barely conceivable Mars might have been inhabitable.

Literature

• Any number of stories, beginning with The War of the Worlds (1898) and continuing into the mid-'60s,^note but see "Other", below featuring intelligent life on Mars, were effectively scuttled when the Mariner 4 probe revealed Mars to be a barren desert. Since then, most Speculative Fiction featuring Martians has been more tongue-in-cheek (see Mars Attacks!) than previously. Subsequently, many stories now say the Martians simply spoof the probe's sensors, just to maintain the façade.
  • In some stories (also beginning with The War of the Worlds), Mars' inhospitable conditions are used as the reason why Martians are invading. Their world is used up, so they want a fresh one.
• Robert A. Heinlein was a little overoptimistic about the prospects for life on other planets. RAH actually admitted that he had an irrational conviction that life would turn out to be ubiquitous in the universe, in an article in which he clung to the hope as late as 1965. His intellectual side suspected he was wrong by then, but he called it a 'religious conviction' that he would not let go of absent thorough exploration of Sol IV.
  • His Martians were usually large, thin and three-legged; an ancient race who had built the canals and were now 'resting' (though often having superhuman powers when they could be bothered).
• Vacuum cementing occurs naturally on the Moon: fine dust particles from lunar impacts are converted to rock over time since they lack a layer of absorbed gas. Larry Niven cunningly extrapolated from this discovery to Mars, which does have an atmosphere. In Protector (and other Known Space stories) Mars is covered in a deep layer of dust so fine it acts as a liquid, since vacuum cementing can't occur. Since this story was written, Mars landers and rovers have conspicuously failed to disappear with a "gloop".
• The 1960 book Lost Race of Mars by Robert Silverberg told the story of two preteen siblings whose parents were taking them to Mars to spend a[n Earth] year, starting in the middle of 2017. This story predicted a city, their host city, having been founded in 1991, and a manned spaceship reaching Mars in 1970. Well...
  • And later he wrote a book called Worlds Fair 1996, which featured Martians being put on exhibit at the eponymous fair, which was built on a massive rotating space station. Later in the same book, the protagonist then takes a nuclear powered rocket to Pluto (two weeks at a constant 1G thrust!) to get even more exotic specimens to display...
• The Martian Chronicles by Ray Bradbury featured a Mars with alien cities, water filled canals and a human breathable atmosphere. Understandable, considering the stories were written in the 1940s and 1950s. Far less understandable is why this was adapted into a TV miniseries in 1979, long after actual probes proved none of this was possible.
• "A Martian Odyssey", a short story penned in the 1930s, combines. In it, four men (an American, a Frenchman, a German, and a Russian), blast off to Mars through the miracle of atomic explosions and find it teeming with life and a miracle cancer cure.
• The Space Trilogy: The valleys of Malacandra (Mars to us Earthlings) in Out of the Silent Planet were meant to be the cause of the canals detected by Percival Lowell. Alas, even at the time that the book was published, evidence was mounting that what Lowell saw was just an optical illusion.

Newspaper Comics

• A Non Sequitur comic strip had a visiting Martian who took this a step further, claiming that his people are actually living on "the other Mars", which is always on the opposite side of the Sun from Earth. This idea was once a possibility too, but not only have we had probes on the opposite side of the sun from Earth, we would be able to tell by the effects of gravity on other planets.

Radio

• Journey into Space: In The Red Planet, a journalist asks Jet about the possibility of finding canals on Mars. Jet notes that this was a popular theory in the 19th Century but he is doubtful of their existence. Once they arrive on Mars, however, they find an ancient city built in the middle of a canal. Mitch suggests that it may be natural but Jet points out that its unnatural formation precludes that possibility. Lacus Solis, otherwise known as the Eye of Mars, is depicted as the Martian capital due to many canals intersecting in that area, as was suspected to be the case by Percival Lowell. In 1965, the NASA spacecraft Mariner 4 took the first close-up photographs of the Martian surface. These photos confirmed that the canals were nothing more than an optical illusion, as Joseph Edward Evans and Edward Maunder had speculated in 1903.

Web Original

• In Genius: The Transgression, when it was proven Mars was uninhabitable, the resulting wave of Mania made a Martian Empire. The resulting war was long and bloody. (This actually happens every time science marches on in a big way, but this was the most recent incident.)

Other

• In the late 1950s and 60s, one of Mars's moons, Phobos, was thought to be hollow, for esoteric sciencey reasons (the moon was/is falling toward Mars). President Eisenhower even went on record, saying, "Its purpose would probably be to sweep up radiation in Mars's atmosphere, so that Martians could safely operate around their planet."
• The whole "life on Mars" hype got going after Italian astronomer Giovanni Schiaparelli claimed to have seen 'canali' (which actually means 'channels' or 'grooves', not 'canals' as it was mistranslated) on the surface during the opposition of 1877, a claim later backed up by other astronomers of the day. However, as better telescopes became available in the early years of the 20th century, these 'channels' proved to be optical illusions. This should have become a Discredited Trope as early as 1907, but science fiction writers ignored this until the Mariner probes destroyed the last scraps of Plausible Deniability.
  • The Pierre Guzman Prize was announced in 1900, and was to be given to the first person to initiate two-way conversation with an alien civilization... except for Martians. The creators of the prize were so confident in the "life on Mars" hypothesis that they specifically excluded Mars because they assumed communicating with the planet would be too easy. The prize sat unclaimed for most of the 20th century,^note although Nikola Tesla did contest it in the 1930s long after the Martian canal theory had been discredited by scientists. Finally, in 1969, it was decided to award the prize to Neil Armstrong and Buzz Aldrin, who achieved the next best thing: direct physical contact with the surface of another world.
• Ultima: Worlds of Adventure 2: Martian Dreams deliberately plays tongue-in-cheek with the outdated science. Not only is Mars home to canals, frozen icecaps, ambulatory plantlife and an ancient, plant-based civilization, you also get transported there by a giant cannon, there's no problem with air pressure, it's warm enough that you only need some thick clothes to walk around, and the low oxygen content only makes you sluggish and easy-tiring (representing a stat decrease) which can be offset by chewing naturally-occurring "oxium", essentially solid oxygen.

Jupiter

Outdated depictions of Jupiter.

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Film

• When Stanley Kubrick moved 2001: A Space Odyssey from Saturn to Jupiter, he did so because he couldn't pull off the special effects for a realistic depiction of Saturn. Then the Voyager probes in 1979 discovered that one of Jupiter's moons, Europa, has a huge amount of ice, and eventually found a subsurface ocean that makes Europa more likely to harbor life than Mars. This inspired Arthur C. Clarke to eventually write three more novels, making Europa the central setting of the series.

Literature

• Isaac Asimov's Lucky Starr and the Moons of Jupiter: In 1956, only 12 major satellites were known, and the magnitude of Jupiter's radiation was unknown. However, a preface added to the novels in The '70s, talks about the discoveries made by the Pioneer X probe, such as a thirteenth satellite that orbits near Adrastea (Jupiter's ninth satellite) and the enormous magnetic field Jupiter generates.
• Arthur C. Clarke:
  • Imperial Earth portrays Titan as being an important source of hydrogen, as it's the only place in the Solar System to have both low gravity and lots of hydrogen. It also mentions Ganymede as part of a list of inhabited worlds that have no hydrogen to spare. We know now that Ganymede is literally covered in ice, as are many of the other outer planet moons, and hydrogen can be obtained from ice by melting and then electrolysing it.
  • On the other hand, the later book 2010: Odyssey Two does portray Ganymede as having ice... however, it portrays it as having only ice, with no liquid water (unlike its sister moon Europa). We now know that Ganymede actually has a subsurface ocean of liquid water, just like Europa does.

Live-Action TV

• Doctor Who: In "Revenge of the Cybermen", the Doctor refers to Jupiter having 13 moons (including the asteroid Voga, which was captured by Jupiter's orbit fifty years before the story's setting). Many more moons have since been discovered. In fact, Leda was discovered in September 1974 whereas the story was broadcast in early 1975, meaning Science Marched On between recording and transmission!
  • One of the novels attempts to Hand Wave this by saying that in the future the extra ones were destroyed as part of an effort to feng shui the Solar System in order to attract foreign investment.

Radio

• Journey into Space: In The World in Peril, Doc notes that Jupiter has twelve moons. In 1955, this was believed to be the case but numerous others were discovered in subsequent years. With the discovery of twelve additional moons in 2018, there are now 79 known moons.

Saturn

Outdated depictions of Saturn.

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Comics

• British sci-fi comic strip Jeff Hawke, back in The '50s, described Saturn's moon Titan as having "a thin methane atmosphere". We know today that Titan has a thick atmosphere of mostly nitrogen, with a little methane. It took the invention of astronomical satellites to discover this, since the spectroscopic signature of nitrogen could not be observed by ground-based telescopes.

Film

• In Gattaca Vincent claims that no one knows what the surface of Titan is like due to its dense cloud layer, and proudly states that his mission will be the first to discover what's really down there. Unfortunately he's a few decades too late as the Huygens probe landed on Titan in 2005 and photographed the surface.
• 1977's The Incredible Melting Man has humans landing on Saturn's surface. The Voyager probes' analysis of the planet's composition and temperature would establish that Saturn's only solid portion is its core, which is much too hot and high-pressure for even robots to visit, just a few years later.
• Related to all the stuff with Arthur C. Clarke from 2010 on, it was later discovered that one of Saturn's moons, Enceladus, also has a subsurface ocean. So it turns out Clarke's original idea of using Saturn as the setting for the Monolith was just a couple moons away from the bullseye. (He originally targeted Iapetus.)

Literature

• Isaac Asimov:
  • Foundation and Earth: The heroes track down Earth That Was using fragmentary references, including a clue that one of its neighboring planets had three broad rings. While three of Saturn's rings are larger than the others, there are at least seven. They remark on how impossibly large the rings are indicated to be, and assume it must be an exaggeration. However, extrasolar planets with even larger rings were found in the early twenty-first century.
  • "The Martian Way": When Dr Asimov wrote the story, it was believed that Saturn's main rings were ten miles thick, but more recent analysis and flyby probes have shown that those rings average around 30 feet thick. The enormous mountain-sized ice block in the story is not realistic, although they could have strung several house-sized chunks together or gone to the Oort Cloud for ice instead.
  • Lucky Starr and the Rings of Saturn:
    • In 1957, only nine satellites of Saturn were known, and Mimas was the closest known satellite to Saturn. However, the preface explains that in 1967 Audouin Dollfus discovered a tenth satellite of Saturn, one that was closer to the planet than any of the others, and named it Janus. After the preface, in 1980, it was confirmed that the orbit known as Janus actually had two satellites in co-orbit. The discovery and naming of Epimetheus was back-dated in credit to Richard Walker in 1966, causing Saturn to have two moons closer than Mimas.
    • In 1957, the only planet known to have rings was Saturn. However, the preface explains that in 1977 astronomers discovered Uranus also has rings. After the preface, rings were conclusively photographed for Jupiter (1979) and Neptune (1989) by the Voyager 1 and Voyager 2 probes.
• John Varley's Gaea Trilogy: Titan starts off a trilogy with the characters' excitement at having discovered the twelfth moon of Saturn. Today it's known that Saturn has at least sixty-two moons, not counting hundreds of "moonlets" embedded in its rings.

Pluto

Outdated depictions of Pluto.

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Literature

• Empire from the Ashes was written in the late '90s, so not only is Pluto considered a planet, but its orbit is explained as being the result of a gravitational disturbance from Dahak's Enchanach Drive when the ship first arrived in the Solar System.
• In Rosemary Wells' book and the Animated Adaptation of "Emily's First 100 Days Of School" which has 100 pages with events related to the number, the ninth page is where Emily and her the other students tell how many planets the Solar System has. Pluto is included; this was made years before Pluto's planetary status was revoked.
• Isaac Asimov's Extraterrestrial Civilizations: Dr Asimov lampshades the progress of astronomical science, pointing out that Pluto was considered larger than 2,900 kilometres (1,800 miles) until 1978, when Charon was observed and Pluto was discovered to be much smaller than previous estimations.
• Larry Niven's World of Ptavvs: Amusingly, this story predicted Pluto's demotion long before it happened; A spaceship moving close to the speed of light was supposed to impact Neptune one and a half billion years ago, but one of Neptune's moons got in the way, and was knocked loose (This is implied to be Pluto).

Live-Action TV

• Stargate Atlantis: In "Brain Storm", Rodney goes to a meeting of scientists. The real Neil deGrasse Tyson (i.e. the guy largely responsible for Pluto's demotion) plays himself as Rodney's enemy at university. Rodney sneers "Way to make all the little kids cry, Neil. Does that make you feel like a big man?"
• The Star Trek: Voyager episode "Distant Origin" features a race of dinosaurs who escaped Earth prior to the K-T Event millions of years ago. The few things that they remember of the Solar System were the "nine moons" which is a reference to what, at the time of airing, were our nine planets. Less than ten years later, Pluto received its official demotion, in part because other bodies have been found on the fringes of similar mass. If a space-faring people counted in Pluto, they might be expected to have more than nine.

Video Games

• In Fallout 2, there's a puzzle to which the answer is to pick options in order of which planet is furthest from the Earth (Plutonium, Neptunium, etc). Pluto's still the furthest on the list, but it's now the only non-planet. On the other hand, the Fallout-verse runs on SCIENCE! rather than actual science.
  • Especially amusing since Pluto's orbit is such that it is not always the furthest out. There are lengthy portions of time^note About 20 years out of every 248-year Plutonian orbital cycle; the last such period was 1979-1999 where Neptune is further out than Pluto.
  • Furthermore, at the time Fallout 2 was released, Pluto was closer to the sun than Neptune was. But it wasn't in the time period in which Fallout 2 takes place.
• Pluto got demoted during the development of Mass Effect, and BioWare never really got to fixing that. Mass Effect 2 corrects this by calling Pluto an "ice dwarf" and not showing its orbit. It's still more important in-universe than even the regular planets because it's orbited by the Charon Relay. Speaking of which: recent pictures by the New Horizons probe have shown that Pluto's moon Charon appears to be just a moon and not a huge alien artifact enabling interplanetary travel, and Mass Effect's Flavor Text for Pluto makes no mention of the additional four moons detected by New Horizons and the Hubble Space Telescope.
• In Star Control II the Sol (i.e. Earth) system includes Pluto (complete with a regular, "flat" orbit) as the ninth planet. Fwiffo mentions that it's as far away as he could get from Earth while still technically keeping his post in the system, when in fact there would be plenty of more distant Kuiper Belt objects on which to park his ship. However, the Kuiper Belt was discovered in 1992, the year the game was released, and the Pluto-sized Kuiper body Eris not until 2005.
  • The Continuity Reboot Star Control Origins, released in 2018, does not count Pluto as a planet on the map screen. Instead, it replaces Pluto with another gas giant beyond Neptune's orbit, called "Artemis". Apparently, in-universe, Artemis was discovered in the 2040's, and is considered a very boring and inconsequential ball of gas.
• In Warframe, Pluto looks like this◊, a greyish blueish texture clearly based on Ganymede. It wasn't until about two years later that New Horizons did its famous fly-by and showed Pluto really looked like this◊, a brownish hue with a surface more in line with Mars.

Western Animation

• Futurama, set in the 3000s, depicts Pluto as having only one moon. We know in 2013 that Pluto actually has five moons.
  • Given the events that have transpired in that universe, including Earth being conquered by aliens twice, it's not unlikely that something has happened to Pluto and its moons as well.
  • Though Hydra is mentioned in the fourth movie.
  • Not only that, but the Heart (which was not discovered until 2015) is absent. (This one is more understandable.)
• The Magic School Bus (as well as the tie-in video game and the books) depicts Pluto inaccurately compared to today's understanding:
  • No "Heart", and it is depicted as being blue... which to be fair was an accurate representation of hypotheses surrounding Pluto's appearance at the time. This was actually acknowledged in the after-episode conversation with the in-universe producer (which was also used to explain why certain scientific elements were ignored for narrative purposes), which he even responded with "until one of you kids grows up to be a scientist, we have to guess."
  • Only Charon appears as its moon—the other four weren't discovered until about ten years after their releases.
  • And most importantly, it's considered a planet.
  • The corresponding book does address all of these things in prints made after 2006. The educational asides address such facts as Pluto's demotion, Ceres's lesser-known promotion from asteroid to dwarf planet, and the existence of the rest of the Kuiper Belt.

Multiple

• The Great Astronomy Mess Up, namely the demotion of Pluto to dwarf planet status (and the lesser-known promotion of Ceres, which had itself spent fifty years as a planet before being demoted for the exact same reason Pluto was, from asteroid to dwarf planet status), dealt quite a blow to stories in which Pluto was still called a planet in the future, such as Star Trek. Not all astronomers are happy with the classification; it's quite possible that it might change back at some point in the future. This is scant comfort to 20 Minutes into the Future shows, though...
  • Interestingly, Nicholson Hall at Louisiana State University (home of the school's astronomy department and the Landolt Astronomical Observatory) has a stucco medallion above the south east entrance which depicts the eight "official" planets and their symbols◊. The building was built in 1937, seven years after Pluto's discovery, but while it was still languishing in categorical limbo. Luckily, the dwarf planet's reclassification in 2006 rendered the contemplation of changing the mural moot (although unfortunately, renovations have made that particular entrance inconvenient and unnoticed).
  • The countless discoveries of the "tenth planet" in various works of fiction, which would now be only counted as the ninth (and the existence of such a planet is now considered very unlikely anyway). Sailor Moon (where it's called Nemesis), The Hitchhiker's Guide to the Galaxy (Persephone, to go with Pluto, but more commonly referred to as Rupert), ALF (Alvin), Doctor Who (Mondas, the Cybermen's home planet), and many, many others.
    • In fact, the issue of Pluto's classification was forced by the discovery of an object that was both larger and more distant and was thus immediately labeled by the media as the solar system's tenth planet. Said object was appropriately named Eris, for the Goddess of Discord.
  • The Star Trek: The Next Generation novel Before Dishonor hung a lampshade on this; two characters discuss how Pluto has been promoted and demoted ten times in three hundred years, and one of them asks, "can't they make up their damned minds?" They then note it's no longer an issue after the extra giant Borg cube FREAKIN' EATS PLUTO!.
  • One interesting thing to come out of the Pluto demotion is that the number of planets in The Planets by Gustav Holst is correct again. Not that people haven't tried creating a movement for Pluto.
  • The Pluto-as-dwarf-planet debate got lampshaded late in Super Robot Wars W. Towards the end of the 11 Planetary Masters of Sol plot thread, the members of Neue Waerter are talking about how many planets there are in the Solar System and Pluto is initially left out of the count.
    • Waaay before that, the character discuss how there's 8 planets but there used to be a 9th one. However, nobody can remember Pluto's name. However, Pluto gets the last laugh, because it's right next to it where the Original Generation villains have parked their hideout. You even get to see Pluto on the second to last battle's map.
  • Lexx identifies Pluto as a planet, but, in its defense, it does have to think about it for a second, and qualifies its final planet count with a "maybe".
  • In Ben 10: Alien Force, the episodic villain blows up Pluto cause he could. Ben shows shock at them destroying Planet Pluto, only to be corrected by the alien power he's supposed to be using (long story) that it's a dwarf planet.
  • Depictions of Pluto that not only portray it as a planet but as one that is completely and utterly different from the big ball of ice we know it as today, Yuggoth from H. P. Lovecraft's "The Whisperer in Darkness" being one of them.
  • Although the confusion is primarily a result of reclassification rather than actual new data, one of the reasons why it got called a planet when it first was found was that it was thought to be a fair bit bigger than it actually was^note As late as the late 1960s, it was still considered plausible that Pluto was around the size of Earth. Its size got down-graded several times over the decades.
  • They tried so hard to make the Pioneer plaque timeless and universal, but oops, they showed nine planets. It'd be a bit hard to go back and fix it now. (It also only shows Saturn with rings. Within ten years of its launch, it was discovered that Jupiter, Uranus, and Neptune have rings as well, though much less prominent ones.)
  • There was a wave of Sailor Moon fanart depicting Sailor Pluto being angry at the reclassification (sometimes to the point of attempting to "persuade" the involved astronomers to change their stance, with variable results depending on the story), or even dismissed from the Sailor Senshi because of it. Sometimes, however, she's merely sardonic about the decision and the logic behind it, and may express complete indifference to the matter for one reason or the other (almost always partly because it has no actual effect on her powers).
  • Milky Way and the Galaxy Girls was created back when Pluto was still considered a planet. Pluto is still a character and is still treated like a planet in official media but the official blog for the series shows that Pluto is well-aware she's no longer a planet. And she reacted as expected from her.
  • Lampshaded in Batman: The Brave and the Bold, in which the Planet Master, a villain with powers relating to the planets, unleashes the "Cold of Pluto", only to be reminded that Pluto is no longer a planet. Planet Master is not pleased.
  • Orbit, a webcomic about anthropomorphised planets, was written after Pluto's demotion. Pluto was so shocked by being demoted that he went insane from grief.
  • As of 2016, some astronomers think there might be a ninth planet out there after all. As this planet's existence is inferred from its influence on small objects beyond the Kuiper Belt, there is little risk that it will be demoted later.
  • For reference, as decided by the International Astronomical Union, the three criteria to be considered a true planet are: it must orbit the Sun, it must be massive enough to be shaped into a sphere by its own gravity, and it must have cleared the neighbourhood around its orbit (simply put, it has to be the gravitationally dominant body in its region of space). Pluto fails the final criterion by being in a 2:3 orbital resonance with Neptune wherein Pluto is at Neptune's mercy while Neptune is completely unaffected by Pluto, hence Pluto is considered a dwarf planet.

Other

Anime

• GunBuster (written in 1988) featured an expanded solar system with several more (very large) planets beyond Pluto's orbit (Lucifer, Metis, Kaminatsuki, Jupiter II) and a counter-star to the Sun, called "Nemesis". Modern astronomers have conspicuously failed to find any more non-dwarf planets beyond Pluto, and certainly not a counter-sun.
  • This was shortly after Alvarez's theory that the dinosaurs were killed by an asteroid strike; there was speculation at the time that mass extinctions on Earth had a periodicity possibly caused by a disturbance in the (then speculative) Kuiper Belt, which caused asteroid strikes throughout the Solar System. This was postulated to be caused by the gravitational disturbance created by a large unknown planet or sun far past the orbit of Pluto-'Nemesis' was a proposed name for such a body.
  • As of now, the possibility of a large planet beyond Pluto is once again being entertained by astronomers, so it's possible that Gunbuster was right after all.

Film

• Avatar put its fictional world, Pandora, beyond the well-charted regions of the solar system yet within reach with mostly realistic technology in the movie's timeframe—it's a moon orbiting a fictional gas giant Polyphemus in the Alpha Centauri system. Being so close to the cutting edge means that it doesn't take long for science to march on—as of now, the evidence points to the absence of any gas giants, and if there are any planets there at all, they're small rocky ones.
  • A team of exoplanet hunters claimed detection of a small, rocky planet around Alpha Centauri B in 2012. Around a year later a paper was published purporting that this detection was spurious. There is currently no consensus on which is the most correct interpretation.

Literature

• The hypothesis that the Asteroid Belt was the remnants of an exploded planet was not disproven until the late 1960s (when it was figured out that adding up all the asteroids would still make something smaller than our own Moon). Hence a lot of authors such as Asimov, Heinlein, etc. presented this as fact, even having characters find physical evidence in the Belt of a civilization that once lived on it.
  • In the Giants Series by James P. Hogan, Minerva was the planet, the Lunarians were the survivors of a nuclear war that blew it apart. The big chunk became Pluto; the rest formed the Asteroid Belt.
  • Jennifer Fallon's Tide Lords series also makes use of this trope despite being published in 2008.
  • Also used in Robert Rankin's The Brentford Triangle (“Where's the fucking planet gone?”) — this being Rankin, it's justified by Rule Of Mind Screw.
  • In Doctor Who, the Fourth Doctor once faced off with an alien menace from the Fifth Planet. It was explained that this race was so dangerous that the Time Lords "time looped" the planet, making it never have existed. But an alien survived.
  • Similar to the asteroid belt theory, John Varley's Titan suggests that Saturn's rings are the remnants of a moon that shattered because giant living space stations kept using it as a nursery.
    • And in more science marching on, although it wasn't because of living space stations, a paper has modeled the origin of the rings as the breakup of a large moon which had its ice layers stripped off as it plunged into the planet.
  • Robert A. Heinlein's Stranger in a Strange Land has the fifth planet being blown up in the distant past by the otherwise generally peaceful, slow to act, but decisive Martians, who deemed its inhabitants a threat to them. Oh, and the main character is their unknowing envoy to Earth, so they can decide what needs to be done with Earth.
  • In Heinlein's Space Cadet, it is discovered that the intelligent natives destroyed their planet through a nuclear war and created the asteroid belt. The mass problem is actually addressed by saying the belt represents less than one percent of the planet.
    • Also in Between Planets by the same author; the fifth planet is the source of advanced technology that the rebels discover remnants of on Mars and use to win freedom from the tyrannical Earth.
  • The idea still pops up every now and then (one of the entries above mentions a 2008 novel, the early 90s Empire from the Ashes series establishes that the asteroid belt used to be another planet, albeit small and airless, and so on). If nothing else, some of the examples can be handwaved as the event that caused the shift from planet to asteroids being far more destructive to the planet then merely blowing it apart in macro-scale chunks.
  • The idea even pops up in Final Fantasy IV, of all places, where the Lunarians are said to have originally inhabited the now-obliterated planet that orbited between "the red planet" and the "Great Behemoth". The original English translation explicitly calls these planets "Mars" and "Jupiter".
  • There is supposed to be research that indicates that if you could get an energetic enough explosion to blast apart a rocky planet, it would probably leave only about 1% of the original mass in the same orbital area. However, models of planetary accretion that assume a gas giant near the inner edge of the zone where water ice can exist (about where Jupiter is) show that a planet would be unable to form in the region of the asteroid belt in the first place. In this age of copious of extrasolar planet discovery, accretion models see constant revisions, considering the inherently chaotic nature of the many-body orbital problem. Time will tell as Science Marches On.
• Isaac Asimov often based plots on then-current scientific information that was later proven incorrect. He typically noted cases of this in later printings (sometimes with a snarky comment that the scientists should have gotten it right to begin with).
  • The Complete Adventures of Lucky Starr: Dr Asimov wrote these stories to teach kids what the solar system is like. Twenty years after first publishing them, many aspects were proven inaccurate, so Dr Asimov included a preface to each story which gave the currently correct information. Some of which is wrong again by now.
  • The Stars, Like Dust: The climactic scenes take place on a type of planet (breathable atmosphere and Earthlike gravity, but no organic life or liquid water) which later science determined was extremely unlikely to exist in the real world. Again, later editions of the book contained an afterword by Dr Asimov, apologizing to the reader for the error and stating he hadn't been able to find a way to correct it without rewriting the entire climax.
  • The Currents Of Space: The plot is based around a theory that stars go nova as a result of runaway nuclear fusion catalyzed by clouds of carbon atoms. Like many of his other stories, when this was proved incorrect Dr Asimov included an afterword explaining the error, as well as the science behind the new scientifically accepted theory, but pointed out that he could not change the story without re-writing the entire plot.
• Stephen Baxter's Xeelee Sequence climax was somewhat hit hard when studies of the Great Attractor showed not only it's both less massive than was thought and has an even more massive cluster behind it whose gravity is pulling our galaxy towards there but also that no looped cosmic strings have been found to date there. On a related note, cosmic strings — what the Xeelee use as building blocks are unlikely to exist, having had at best a very limited role in forming the structure of the Universe and instead it having growth from quantum fluctuations left from either cosmic inflation or the Big Bang itself.
• When 51 Pegasi b, the first extrasolar planet orbiting a Sun-like star, was discovered its closeness to its star (seven times closer than Mercury's distance to the Sun) led the discoverers to suggest it was the stripped, solid, core of a brown dwarf- a body intermediate in mass between a star and a planet and unable to fuse hydrogen as a star- since at the time it was thought no planet so massive could orbit so close to a star (the rocky planet scenario was used for the Hal Clement's novel Exchange Rate). Today, after the discovery of hundreds of similar planets, it's thought 51 Pegasi is a gas giant planet similar to Jupiter that ended orbiting so close after forming much farther away and migrating there.
• Aeon 14: M.D. Cooper tries to use the most current astronomy and astrophysics information available, but sometimes this happens. Some stars near Earth that the series visits have since been discovered to have planetary systems (they appear to be far more common than previously thought) that sometimes don't match what earlier books said—notably LHS 1565, which features prominently in the second book, A Path in the Darkness, and is said to have no planets at all (Cooper commented that she worked really hard to pick a star not likely to have any). The setting does have a built-in handwave, however, as many star systems have been extensively terraformed, the technology for which is advanced enough to rearrange planets, break them up, or form entirely new ones by mashing rocks together.
• Robert Heinlein figured out how to get something to navigate within the solar system back in the 1950s in his juvenile novel The Rolling Stones (1952), by lining up the locations of known stars and mirrors to form a type of parallax to get your location, which is now used for satellites and probes for positioning. Since the novel was printed in serialized chapter format within the Boy Scouts of America's Boy's Life magazine, it was intended as an interesting intellectual exercise (land navigation being a skill that was heavily stressed with the Boy Scouts). He also mentioned that the health benefits of zero-g (itself a mistaken term, now replaced with microgravity) were well known. These days, long term exposure to microgravity is well known to be bad for one's long term health, and not just because of bone and muscle atrophy, but also because of the detrimental effects it has on the human immune system.
• Frank Herbert's Dune is set on Arrakis, a planet with some indigenous complex life that orbits the star Canopus. At the time it was written, Canopus was thought to be only around 60 to 100 light years away (due to the more rudimentary methods of measuring parallaxes), and thus a star much more luminous than the Sun but perhaps still plausible for harboring a planet with evolved life forms. We now know that, at over 300 light years away, it is a supergiant with a luminosity 15,000 times the Sun's, and thus almost certainly from the massive, blue end of the main sequence (before it became a yellow-white (F) supergiant) and thus perhaps only a few tens of millions of years old—hardly enough time for life to evolve, at least the way we understand the process (although later books float the idea that Arrakis was artificially seeded with life sometime before the Butlerian Jihad).
• William Hope Hodgson's The Night Land is built around the premise that the Sun would cease to shine some time in the distant future. This idea was actually accepted as scientific fact at the time the book was written- based upon the idea that the Sun got its luminosity from chemical fuel compressed by gravity, and that said source would run out in a few million years. Then came along the idea of nuclear fusion... The current prediction is that the Sun will cease to shine in the distant future, but it's very distant and the Earth will become utterly uninhabitable long before then.
  • Later authors writing in the same universe have rectified this by suggesting that the Eldritch Abominations had something to do with the Sun going out.
• In Melisa Michael's Skyrider, the protagonist lives in the Belt and is constantly dodging rocks, requiring excellent flying to get through rocks and hiding from the patrol in a dense patch of rocks. Unfortunately the asteroid Belt is just not dense enough. Even in the densest part, if you were standing on one rock you wouldn't be able to see a single other rock.
• Some Larry Niven stories include mention of the Moon's gravity "skimming off" some of the Earth's atmosphere, without which it would be as inhabitable as Venus. This was later discredited, and is noted in his collections.
• In Search the Sky, by Frederik Pohl, Azor's sun has "an unpleasant bluish cast to it", and is therefore a low-end A star. Therefore Azor, as a Goldilocks planet, has to have a much longer year than Earth's. Yet Ms. Cavallo speaks of another FTL traveler who arrived "seventy-five years ago", and who died about the time Ross and Helena arrived. Even on the gerontocratic world of Gemser, people do not live that long.
• Carl Sagan's Contact has being in space extend the lives of mammals and leave them with fewer diseases, so near the turn of the millenium there's a whole industry of wealthy older people trying to prolong their lives by living on glamorous, specially built space stations. Since then it's proven that living in space results in massive degradation of a lot of the human body, plus bacteria becomes more virulent, and living in space is miserable.
• Cordwainer Smith's "Scanners Live in Vain" uses the fanciful premise that unscreened radiations present in space would leave space travelers in unbearable pain, such that only condemned criminals whose sensory nerves had been cut could function there. While radiation in space is a real threat, it's not immediately painful and there are other ways of protecting against it (indeed, cutting sensory nerves would actually be worse than useless, since it would interfere with people's senses without protecting them against radiation).
• E. E. "Doc" Smith based the back story of his Lensman series on the idea of two galaxies (one being our Milky Way) passing through each other edge-on with both emerging relatively intact in the end (the gravitational fluxes caused therein giving birth to the intelligent life in those two galaxies). Late in the 20th century, evidence emerged that the cores of galaxies are massive, highly-condensed lumps of matter: Supermassive Black Holes. Given this new prevailing theory, Smith's concept cannot occur as the gravities of these cores would cause two converging galaxies to merge instead.
  • At the time he was writing, it was mainly thought that planets were the result of close encounters between passing stars in which the gravity of one star sucked a bunch of material up off the other one and left it hanging in space, where it condensed into planets; such encounters being extremely rare, there would only ever be one or two planets per galaxy supporting intelligent life at any given time. Thanks to the galactic interpassage, though, both our galaxy and Lundmark's Nebula would have experienced a huge number of such encounters, and would therefore be exceptions, hosting large numbers of life-supporting planets as required by the plot. Now, however, it is generally thought that the formation of planets goes along with the formation of the stars they orbit, as both condense out of the same cloud of interstellar matter, so nearly all stars in all galaxies have planets—in which situation the Eddorians would be spoilt for choice and could just as easily have settled in a galaxy so distant that even the Arisians wouldn't realise they were there. However, since the Eddorians didn't know the Arisians were there, they wouldn't have had any particular reason to avoid the Milky Way, either.
  • In addition, even if planets were the result of close encounters between stars, them being rare was based on the assumptions that such encounters were extremely unusual, and galactic collisions even more so. We now know that many, perhaps even the majority, of stars exist in double or multiple star systems and many supernovae are the result of actual collisions between them. It is also thought that elliptical galaxies are the result of collisions and mergers between two or more galaxies, and we even have pictures of galaxies either in the process of colliding or which have just passed through each other, being more or less disrupted by said event. Since galaxies mostly exist in gravitationally bound groups this will be the ultimate fate of the vast majority.
  • To be somewhat fair, it's also currently known that in galaxy collisions gas clouds, much larger than stars, present on them collide causing very extensive star formation, thus a lot of planetary systems.
• Whitley Strieber and James Kunetka's 1984 novel Warday has a satellite discover five planets orbiting Barnard's Star in 1985, with one of them possibly being Earth-like. As of 2023, there are no confirmed exoplanets in the system, with Barnard's Star b being disproven in 2021–2022, and if any do exist, they are bound to be much smaller than the Earth.
• Catherynne M. Valente's novel Radiance is a deliberate tribute to outdated, romanticised depictions of Earth's solar system in pre-WWII pulp SF, being set in a universe in which all the solar system's planets are habitable by humans and have living ecosystems.
• Hayy ibn Yaqzan is a twelfth-century novel about a man who discovers truths about the world through observation and rational thought. Not all of his discoveries have held up to modern science, such as his belief that the celestial bodies orbit the Earth and are contained in spheres.

Live-Action TV

• Carl Sagan's documentary Cosmos: A Personal Voyage: When the DVD edition was released, it included an epilogue to each episode along with commentary explaining each point where the science discussed was not quite up to date or supplanted by new research. Surprisingly, the vast majority of the series stands the test of time.
• The British quiz show QI has a Running Gag of messing with its contestants with the question: "How many moons does the Earth have?"
  • The first time it was asked, regular contestant Alan Davies answers (resigned, knowing such an easy question can only be a setup) "One" and gets flashing lights, klaxons, and Stephen Fry with "Sorry, that is incorrect. The correct answer, of course, is 2": Luna and Cruithne (an asteroid that has a peculiar orbit around the Sun that sometimes temporarily brings it into a "quasi-orbit" around Earth). Note that no scientist has ever considered Cruithne to be a moon, since it is not permanently locked in orbit around the Earth; the show was deliberately using an extremely loose definition of "moon" to mess with the contestants.
  • The following season, Stephen asked the same question, which Davies then tries with the previous given correct answer. Incorrect. The answer had changed in the time between episodes: either it's "5", because they found three new Cruithne-like moons, or "1", because none of them count.
  • The Series K episode "Knowledge" discussed this trope; naturally, it used as an example the moon question. The "correct" answer this time around? About 18,000, these being temporarily captured small objects that orbit for a while before leaving; of these only one has actually been observed.
  • The same question came up in Series L, with the answer being "Earth has no moon". The reasoning is that the IAU definition of a "planet" includes the requirement that it must have sufficient mass to have cleared its solar orbit of other objects (this is the requirement that Pluto fails). While the Earth's orbit has been cleared, Earth did not manage this on its own: the Moon's mass naturally contributed as well. Therefore, under a stretched interpretation of the IAU planetary definition, the Moon is itself a planet, and is in a binary orbit with the Earth. Naturally the contestant called BS on that idea.

Music

• They Might Be Giants' edutainment CD Here Comes Science includes Why Does The Sun Shine? (The Sun Is A Mass Of Incandescent Gas), their popular cover of a similar product from the 1950s, because it is a damned catchy tune and likely to capture kids' attention. In the interest of this trope, however, it is now followed by an updated version, Why Does The Sun REALLY Shine? (The Sun Is A Miasma Of Incandescent Plasma). As for the rest of the songs, only time will tell...

Theatre

• In Hamlet, the line "Doubt thou the sun doth move" was written under the contemporary thinking that the sun revolves around the earth. It's not entirely wrong, though, since the sun does move around the centre of the galaxy.

Video Games

• Most works of fiction depicting the Milky Way galaxy portray it as a regular spiral galaxy, a shape taken for granted given our understanding of it. However, there has been evidence discovered of (what is currently believed to be) its true shape, which is a barred spiral galaxy.
  • Mass Effect is an example that portrays our galaxy right. The franchise also managed to avert the issue of potentially soon-to-be-proven-incorrect planetary systems by making the player unable to visit the stars nearest to our Solar System, giving the handwave that "Mass Relays allow to colonize more suitable systems that are much farther". However, there's a straight play with the space between galaxies, known as "Dark Space", which is depicted as a lightless void where nothing can survive except for the cosmically powerful Reapers; in the years since the last game came out, astronomers have discovered a significant number of "rogue stars" floating around in intergalactic space, some of which may even have habitable planets.
  • Another game that did get the shape of the Milky Way right was Halo 3.
• Rage (2011)'s Backstory has most life on Earth wiped out by the impact of the real-life asteroid 99942 Apophis, then speculated to have roughly a 1 in 37 chance of hitting Earth in 2036. Since then the impact odds have been revised significantly downward: the latest (2013) calculations say Apophis is going to miss us by 35 million miles, about a third of the radius of Earth's orbit.

Other

• Originally, scientists thought that the universe will end when gravity finally stops the universe from expanding and making it collapse back on itself in a Big Crunch. However, new observations show that the opposite is true: the universe is and will eventually expand forever, and its expansion is actually accelerating due to the presence of dark energy, which gradually weakens gravity as it accumulates over time^note Some astronomers have proposed that the nature of dark energy may change over time and in the future could become attractive, stopping the expansion of the Universe and precipitating a Big Crunch. However these are just speculations.
• The discovery of TRAPPIST-1, a red dwarf with up to six potentially habitable planets, has made stories involving star systems with large numbers of habitable planets (such as The Verse of Firefly) seem more plausible than many earlier critics believed.
• As noted above, works that feature nearby stars are hit particularly hard, as while they are found to have planets more than often, said planetary systems are quite different to what authors imagined. Only time will tell what will end happening to media depictions of said planets done with current state-of-the-art knowledge.
• Tidally locked worlds, such as Ryloth in Star Wars or one Silver Age depiction of early Krypton, were thought to have an unliveable hot side, an equally unliveable cold side and possibly a narrow band at the terminator which was barely life-supporting. More recent simulations show such worlds, given Earth-like hydrospheres and atmospheres, would have a hot pole, a cold pole, a steady gradation of temperatures between the two, and some almighty powerful winds and currents between the poles.
• It was once believed that the Milky Way was the only galaxy. However, the early 20th century saw the discovery that celestial bodies once thought to be nebulae were actually other galaxies, which incidentally also proved that the universe was far larger than previously thought.
• The geocentric model of the universe, where all celestial bodies orbited the Earth in "spheres", was accepted as fact for over a thousand years. It has, of course, long been superseded.
• Since the 17th century, it was theorized that there must be an unknown planet (known as "Vulcan") closer to the sun than Mercury. This idea was given a boost in the 19th century after irregularities in the orbit of Uranus were found to be due to another planet further out: Neptune. Similar irregularities in Mercury's orbit were thought to have the same cause. Reported discoveries were consistently disproven, however, and the Mercurial orbital irregularities were later explained using Albert Einstein's theory of relativity.
• The Titus-Bode Law essentially stated that each planet's distance from the Sun must be double the previous planet's distance. This law was reinforced when Uranus was discovered and found to follow the same pattern as the five classical planets, but there was one notable problem; under this rule there should be a planet in between Mars and Jupiter. Attempts to find this missing planet led to the discovery of the dwarf planet Ceres and the rest of the asteroid belt. While Ceres's discovery was initially taken as proof of the law, once it was demoted from planet status it became harder to justify, especially because just a few years before Ceres's demotion, Neptune was discovered and clearly too close. This law was damaged further when Pluto was discovered where Neptune was "supposed" to be, and eventually annihilated by the discovery of the Kuiper Belt and extrasolar planets. Ultimately, the Titus-Bode Law is no longer considered credible, and the fact that it appeared consistent up to Uranus was a complete coincidence.

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