Flying Saucer

The stereotypical alien spaceship of many a sci-fi epic is the ubiquitous flying saucer. For some reason spacefaring civilizations across the galaxy have determined that a flying disc is the most effective and efficient means of crossing the void.

In actuality the most efficient design for a spacecraft would likely be a sphere as this shape encloses the greatest volume with the least amount of material. They just don't look very cool or quite as alien, though they have their own charms.

The term comes from Kenneth Arnold's description of a UFO sighting. Arnold described their flight (but not their shape) as "like saucers skipping across water." Nevertheless, the term stuck. Flying Saucers are the most reported type of UFO (and the most commonly hoaxed type as well) though it is unknown if the term was being used by the witness as an interchangeable word for UFO or describing the nature of the UFO (the term UFO describes any possible aircraft shape, as long as it is Unidentified.) Flying Saucers are still reported today, with a recent one reported over Chicago O'Hare airport in 2006.

See also Little Green Men and The Greys, the most common aliens in UFO culture.

Examples of Flying Saucer include:

Anime and Manga

For some reason, the "Adamski" style flying saucer seems to have become iconic in Japanese pop culture, showing up in anime as different as NieA 7 and Revolutionary Girl Utena.
Hidamari Sketch: Yuno gets abducted by aliens in said Adamski flying saucer while napping on the school roof, but it is All Just a Dream (or was it?)
The Big Bad in the second Kochikame movie uses a flying saucer capable of creating tornadoes from underneath to terrorize parts of Japan.
One of these is piloted by a stereotypical 'grey' alien (as opposed to the more normal aliens) in an episode of the Tenchi Muyo! manga.

Comic Books

Obscure Silver Age of Comic Books hero Fatman the Human Flying Saucer. After saving an alien, overweight millionaire Van Crawford was given a chocolate milk flavored potion that transformed him into a flying saucer (complete with eyes).
Although he's human, Calvin and Hobbes' Spaceman Spiff pilots a one-seater saucer.

Film

In Independence Day, the Alien Invaders nuke cities by directing a Wave Motion Gun down from the centre of their ships.
Plan 9 from Outer Space, although nonsensically, one of the saucers is described as "cigar-shaped", when it clearly isn't.
- They clearly have some kind of shape-shifting mode, since the scenes with people entering through its hatch show it with flat sides at 90-degree angles, much like a... shed of some sort!
The humans have one in Forbidden Planet. Specifically, United Planets Cruiser C-57D.
And who can forget Exeter's ship from This Island Earth, which could readily be described as a flying cowboy hat!
The Thing from Another World (1951). The search team position themselves around the edge of the crashed 'aircraft' under the ice and realise they're forming a perfect circle, whereupon they become quite excited at having "finally found one".
- Also appears in John Carpenter's The Thing, where the guys find it in the bottom of an enormous crater. There was also the Blair-Thing's hommade craft, though it is blown up before it can be used. Also some have speculated that it would actually work more like a hovercraft as a means of getting to the coast so that it could find more life forms to assimilate.
When aliens appear in a Godzilla movie, more often than not, they're flying around in one of these.
Wild Zero has dozens of flying saucers swarming over Earth to cause a Zombie Apocalypse.
Gamera, in his flying form, resembles a flying saucer made of turtle meat.
The moon-based Nazis of Iron Sky utilize flying saucers as their primary attack vehicles... and they launch from giant carrier zeppelins.
The "interdimensional beings" (read: aliens) in Indiana Jones and the Kingdom of the Crystal Skull used a flying saucer, although you can't see it very well on account of it having been buried for a few thousand years. (It's briefly visible after taking off, right before it jumps into "the space between spaces".)
The preferred method of travel by the Martians in Mars Attacks!
Seen in Earth vs. the Flying Saucers, naturally.
Klaatu arrives in one in The Day The Earth Stood Still.

Literature

The starship Vittoria from Starship Through Space, a 1954 sci-fi juvenile by Lee Correy.
In one of The History of the Galaxy novels, a human colony is attacked by a massive automated mothership built millions of years ago. The main character notes its circular shape and comments that it is the most efficient form for a spacecraft.
In the Perry Rhodan books, most spaceships are spheres but small scouting units are flying-saucer shaped.
In the Animorphs series, the Skrit Na are described as using saucer-shaped spacecraft, implied to be because they need aereodynamic ships capable of traveling through atmospheres quickly as well as through space.
Theodore Sturgeon's "A Saucer of Loneliness" has one descending on New York's Central Park.

Live-Action TV

Star Trek, Federation's standard design for non-shuttlecraft ships, each one is composed a circular or oval saucer attached to two or three warp nacelles attached in different places. Picard's version can separate its saucer section from its star-drive section, as well, though the budget prevented The Powers That Be from having it do this with any regularity.
- The fact that the crew time traveled back to 20th Century Earth at least once provides some fun seeds for Epileptic Trees about the origin of flying saucers amongst human society.
Vree and Streib ships in Babylon 5
The Dalek warships in Doctor Who, as shown on the image above.
The Twilight Zone and The Outer Limits found this trope handy, both for alien and human vessels.
The Gerry and Sylvia Anderson 1970s series UFO (obviously).
The Jupiter-2 from Lost in Space.
The ships in V are saucer-shaped.
The Orion VII and VIII in Raumpatrouille.
Project UFO, being lifted from the pages of Project Bluebook, had its fair share of these.

Newspaper Comics

Aliens almost always use them in Frank and Ernest.

Video Games

Destroy All Humans! is a game about the stereotypical inhabitants of the aforementioned floating disks. Laser beams and brain eating are just extra treats.
One of the many odd things used as transportation by the Item World pirates in Disgaea 3: Absence of Justice.
City of Heroes has the Rikti, whose crashed mothership is an enormous saucer.
Star Control 2 has the Ariloulaleelay, whose Scout ship is a teleporting flying saucer.
In the last level of Metal Slug 3, you blow up several different types of flying saucers on your way to the Mars Peoples' mother ship.
One of the Aeon experimental-class units in Supreme Commander, the Czar, is an Airborne Aircraft Carrier in the form of a flying saucer. Naturally, it has a Wave Motion Gun in the middle. The sequel removes the carrier aspect and trades it for lots more weaker lasers and lots of little bombs. It keeps the giant middle laser, though.
Naturally, some of the alien ships in the X-COM series fall under this, as does one of the ships you can manifacture in the first game.
The Shroobs from Mario & Luigi: Superstar Saga invade the Mushroom Kingdom in these kinds of spaceships.
- Also, the Starshrooms from both Super Mario Galaxy and its sequel.
- In Super Mario 3D Land, if you use a binocular pad to look directly upwards and zoom in to the max in World 1-3, a flying saucer will fly by and disappear.
The enemy mother ship that attacks Katina in Star FOX 64 is a flying saucer. The whole mission is an Independence Day shout out, the saucer will destroy the Katina base with a similar Wave Motion Gun if you fail to destroy it.
The Expansion Pack for Command & Conquer: Red Alert 2, Yuri's Revenge, had Yuri's new third side use laser-armed flying saucers referred to as Floating Discs.
Main vehicle of the Watchers in Dark Void.
Wild ARMs 3 had an Alien Invasion sidequest where you had to shoot down a bunch of these with your Transforming Mecha of a mechanical dragon.
Let's not forget good ol' Space Invaders, which has a saucer flying across the top of the screen every so often. Shoot it down for bonus points!
Antari ships in Imperium Galactica are flying saucers. Interestingly, while the Antari are indeed Grey-like, they are, in fact, descended from human colonists, like most humanoid races.
You'll be seeing a lot of these in Touhou Undefined Fantastic Object. It's a Shout-Out to Space Invaders.
- Turns out they really are undefined objects; they only look like what you think they are.
There are Flying Saucers in Wheeler Acres in Backyard Baseball.
In some games, Kirby can transform himself into a flying saucer with the UFO copy ability.
The Naval Ops series has a handful of flying saucers as enemies, as well as the Halberd series of aircraft that you can acquire for your own ships.
Flying saucers appear in The Sims 2.
Sword of the Stars has these in Zuul Slave Disks, the Ten Rings of the Von Neumann Berserkers and the Peacekeeper Enforcer.
The racing game Re-Volt has a flying saucer as a hidden car, available only via cheats. It pretty much drives like a normal car (though its speed and other characteristics make it a Game Breaker), but hovers a bit after leaping off ramps, sometimes flying for really long distances.
A 3D flying sim named Flying Saucer actually exists. Buggy and not officially released, but available on abandonware sites. In this game you can actually fly inertia-free spaceship and abduct stuff.
Outlive is a game about a war between a Mega Corporation trying to take over the world with an army of robots, and a group of freedom fighters trying to take it back. Then these things show up. Cue the end credits.
They appear in the Fallout universe as well. In one Fallout 3 DLC you get captured and sent to one, which you eventually capture just as another tries to bring you down.
Players can sometimes see flying saucers (labeled as "Unknown Object") zipping about in the X-Universe games. They don't interact with anything in the game, and will fly through the universe until they inevitably plow into something.
One of the two main enemy types in Blitter Boy. As it is a flying enemy, standard attacks pass underneath it, making it the trickier foe to fight.

Western Animation

The pilot episode of South Park.
Marvin the Martian is often seen flying in these.
One Harveytoons film had aliens on flying cups and saucers.
The Autobot Cosmos had this as his alt-mode. As one of the few Transformers who can reach escape velocity unaided, his job was orbital recon. He considered it boring and lonely at times and often got into mischief. He once got into trouble with the U.S. government who thought he was an alien UFO, though technically he is.
- His Japanese name, Adams, is a tribute to George Adamski. However, his alt mode has brought up a bit of Fridge Logic on the TF Wiki: where exactly did he scan his alt mode from?
  - Well, for his Movie universe counterpart it was his native Cybertronian alternate form. It's possible the same is true for his G1 incarnation.
The Great Gazoo from The Flintstones has a UFO; sometimes it's large enough to comfortably fit 1 normal-sized person, and other times he barely fits with his helmet serving as the round top.
The Jetsons fly around in a UFO large enough to fit 4-5 characters comfortably, replacing cars as everyday transport in the future.
Nibbler and his race in Futurama each own their own very small UFO 'warmachines', which can almost contain a whole human with their Nibblonian pilot.
Mator from Unidentified Flying Mater.
Hondo Ohnaka's pirate gang uses one of these in Star Wars: The Clone Wars.

Web Comics

The first event of the first story in The Inexplicable Adventures of Bob is a flying saucer crashing into Bob's roof.
Uryuoms were once shown in one of these in El Goonish Shive, while showing how The Masquerade there worked. The solution? A banner saying 'We are not aliens!'. For most, it's true.
Spinnerette has the Avrocar, the pinnacle of Canadian Aerospace Engineering, which turns out to be a piece of crap. It's actually based off of the actual Avrocar built by aircraft manufacturers Avro. It was also a piece of crap until someone added a heavy rubber skirt, and thus invented the hovercraft.
In Sinfest, the aliens arrive in one.

Real Life

Surprisingly, some speculative designs for advanced shuttles resemble this. One face of the disc receives energy beamed from the ground or from a satellite, so it doesn't need to carry fuel, and, to save even more weight, instead of a physical cone for streamlining it just pushes the air out of its way with Frickin' Laser Beams.
There are also plans for saucer-shaped airplanes, since it's the most aerodynamic shape in existence. The only problem is the horrible maneuverability, meaning that state of the art fly-by-wire systems have to be developed for steering the crafts before anyone can even dream of flying them.
- Early attempts at a disc-shaped aircraft with a fan for lift had difficulty getting more than a few feet off the ground. The design eventually morphed into the first hovercraft.
A disc shape is actually quite useful for a spacecraft that would operate in an atmosphere. Flying edge-on, the whole craft functions as a lifting body, and it can turn much more easily than a winged aircraft. Flying flat-on, on the other hand, is great for using a large-area heat shield on your underside for reentry.
A more down-to-earth example: Frisbee flying discs.
Part of the whole Area 51 controversy was its use as a testing grounds for experimental saucer-ships. It turns out, just adding a fin on the back helps a lot.