 Martian controlled Tripod, from H. G. Wells' 1898 novel The War of the Worlds | |
| Grouping | Science fiction |
|---|---|
| Similar entities | Cryptids |
| Other name(s) | Aliens, space aliens |
An extraterrestrial or alien is a lifeform that did not originate on Earth. The word extraterrestrial means "outside Earth". Extraterrestrials are a common theme in modern science-fiction, and also appeared in much earlier works such as the second-century parody True History [1] by Lucian of Samosata. [2]
The 2nd century writer of satires, Lucian, in his True History claims to have visited the Moon when his ship was sent up by a fountain, which was peopled and at war with the people of the Sun over colonisation of the Morning Star. [3] : 30–31
The way people have thought about extraterrestrials is tied to the development of actual sciences. One of the first steps in the history of astronomy was to realize that the objects seen in the night sky were not gods or lights, but physical objects like Earth. This notion was followed by the one that celestial objects should be inhabited as well. However, when people thought about such extraterrestrials, they thought of them simply as people, indistinguishable from humans. As people had never considered a scientific explanation for the origin of mankind or its relation with other lifeforms, any hypothetical rational lifeforms had by necessity to be humans. Even in mythology, all deities are mostly humanlike. [4] For example, Voltaire's Micromégas features people from Saturn, who are simply of higher proportions. [5]
This was changed by the 1859 book On the Origin of Species by Charles Darwin, which proposed the theory of evolution. This book caused a revolution in fiction as much as it did in science, as authors began to imagine extraterrestrial races completely different from human beings. With the rationale that evolution in other worlds may take completely different directions than on Earth, aliens began to be described as creepy monsters. Usually, authors used features from other animals, such as insects, crabs, and octopuses. Some such aliens are the octopean Martians from The War of the Worlds (1898), the Selenites from First men in the Moon (1901), the birdlike Tweel from A Martian Odyssey (1934) and even a sentient star in Star Maker (1937). [4]
The Barney and Betty Hill incident took place in 1961 when the couple claimed that they were abducted by aliens and subjected to invasive experiments. It was the first recorded claim of an alien abduction, soon followed by others. The description of the aliens made by the Hills, with oversized heads, big eyes, pale grey skin, and small noses captivated the public imagination and was later used by TV shows and films. This started the grey alien archetype. According to Wade Roush, a science and technology writer, "The standard depiction of aliens at that point became the little grey man. So, when Steven Spielberg came along and made probably what are the two most influential movies about aliens – Close Encounters of the Third Kind, and ET the Extra-Terrestrial – the aliens and those movies were both basically variations on the 1950s and 1960s little green or little grey man image". [4]
The advent of TV and films, with extraterrestrials played by actors, toned down the fantasy. For budget reasons, humanlike aliens with just some specific non-human body features became the new standard. This is especially noticeable in the Star Trek franchise. This changed again since the 1990s with the advent of computer-generated imagery (CGI), and later on as CGI became more effective and less expensive, as it allows to generate bizarre lifeforms without being constrained to actors with costumes or mechanical effects. [4]
Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celestial object in fiction in the late 1800s, when it became clear that there was no life on the Moon. The predominant genre depicting Mars at the time was utopian fiction. Around the same time, the mistaken belief that there are canals on Mars emerged and made its way into fiction, popularized by Percival Lowell's speculations of an ancient civilization having constructed them. The War of the Worlds, H. G. Wells's novel about an alien invasion of Earth by sinister Martians, was published in 1897 and went on to have a major influence on the science fiction genre.
The Moon has appeared in fiction as a setting since at least classical antiquity. Throughout most of literary history, a significant portion of works depicting lunar voyages has been satirical in nature. From the late 1800s onwards, science fiction has successively focused largely on the themes of life on the Moon, first Moon landings, and lunar colonization.
Terraforming is well represented in contemporary literature, usually in the form of science fiction, as well as in popular culture. While many stories involving interstellar travel feature planets already suited to habitation by humans and supporting their own indigenous life, some authors prefer to address the unlikeliness of such a concept by instead detailing the means by which humans have converted inhospitable worlds to ones capable of supporting life through artificial means.
Mind uploading—transferring an individual's personality to a computer—appears in several works of fiction. It is distinct from the concept of transferring a consciousness from one human body to another. It is sometimes applied to a single person and other times to an entire society. Recurring themes in these stories include whether the computerized mind is truly conscious, and if so, whether identity is preserved. It is a common feature of the cyberpunk subgenre, sometimes taking the form of digital immortality.
Jupiter, the largest planet in the Solar System, has appeared in works of fiction across several centuries. The way the planet has been depicted has evolved as more has become known about its composition; it was initially portrayed as being entirely solid, later as having a high-pressure atmosphere with a solid surface underneath, and finally as being entirely gaseous. It was a popular setting during the pulp era of science fiction. Life on the planet has variously been depicted as identical to humans, larger versions of humans, and non-human. Non-human life on Jupiter has been portrayed as primitive in some works and more advanced than humans in others.
Saturn has made appearances in fiction since the 1752 novel Micromégas by Voltaire. In the earliest depictions, it was portrayed as having a solid surface rather than its actual gaseous composition. In many of these works, the planet is inhabited by aliens that are usually portrayed as being more advanced than humans. In modern science fiction, the Saturnian atmosphere sometimes hosts floating settlements. The planet is occasionally visited by humans and its rings are sometimes mined for resources.
Pluto has appeared in fiction as a setting since shortly after its 1930 discovery, albeit infrequently. It was initially comparatively popular as it was newly discovered and thought to be the outermost object of the Solar System and made more fictional appearances than either Uranus or Neptune, though still far fewer than other planets. Alien life, sometimes intelligent life and occasionally an entire ecosphere, is a common motif in fictional depictions of Pluto. Human settlement appears only sporadically, but it is often either the starting or finishing point for a tour of the Solar System. It has variously been depicted as an originally extrasolar planet, the remnants of a destroyed planet, or entirely artificial. Its moon Charon has also appeared in a handful of works.
Asteroids have appeared in fiction since at least the late 1800s, the first one—Ceres—having been discovered in 1801. They were initially only used infrequently as writers preferred the planets as settings. The once-popular Phaëton hypothesis, which states that the asteroid belt consists of the remnants of the former fifth planet that existed in an orbit between Mars and Jupiter before somehow being destroyed, has been a recurring theme with various explanations for the planet's destruction proposed. This hypothetical former planet is in science fiction often called "Bodia" in reference to Johann Elert Bode, for whom the since-discredited Titius–Bode law that predicts the planet's existence is named.
The Loch Ness Monster is a creature from folklore that has appeared in popular culture in various genres since at least 1934. It is most often depicted as a relict dinosaur or similar, but other explanations for its existence such as being a shapeshifter or from outer space also appear. It is only occasionally portrayed as threatening, despite its name.
Neptune has appeared in fiction since shortly after its 1846 discovery, albeit infrequently. It initially made appearances indirectly—e.g. through its inhabitants—rather than as a setting. The earliest stories set on Neptune itself portrayed it as a rocky planet rather than as having its actual gaseous composition; later works rectified this error. Extraterrestrial life on Neptune is uncommon in fiction, though the exceptions have ranged from humanoids to gaseous lifeforms. Neptune's largest moon Triton has also appeared in fiction, especially in the late 20th century onwards.
Uranus has been used as a setting in works of fiction since shortly after its 1781 discovery, albeit infrequently. The earliest depictions portrayed it as having a solid surface, whereas later stories portrayed it more accurately as a gaseous planet. Its moons have also appeared in a handful of works. Both the planet and its moons have experienced a slight trend of increased representation in fiction over time.
Fictional planets of the Solar System have been depicted since the 1700s—often but not always corresponding to hypothetical planets that have at one point or another been seriously proposed by real-world astronomers, though commonly persisting in fiction long after the underlying scientific theories have been refuted. Vulcan was a planet hypothesized to exist inside the orbit of Mercury between 1859 and 1915 to explain anomalies in Mercury's orbit until Einstein's theory of general relativity resolved the matter; it continued to appear in fiction as late as the 1960s. Counter-Earth—a planet diametrically opposite Earth in its orbit around the Sun—was originally proposed by the ancient Greek philosopher Philolaus in the fifth century BCE, and has appeared in fiction since at least the late 1800s. It is sometimes depicted as very similar to Earth and other times very different, often used as a vehicle for satire, and frequently inhabited by counterparts of the people of Earth. Following the discovery of the first asteroids in the early 1800s, it was suggested that the asteroid belt might be the remnants of a planet predicted by the Titius–Bode law to exist between Mars and Jupiter that had somehow been destroyed; this hypothetical former fifth planet is known as Phaëton in astronomy and often dubbed "Bodia" in science fiction. Bodia was popular in the pulp era of science fiction, where it was often depicted as similar to Earth and inhabited by humans who might occasionally be the ancestors of humans on Earth, and stories about its destruction became increasingly common following the invention of the atomic bomb in 1945. Additional planets in the outer reaches of the Solar System, such as a ninth planet beyond Neptune or especially a tenth beyond Pluto, appear regularly. Many different names for this hypothetical outermost planet have been used, the most common being "Persephone". Some stories depict so-called rogue planets that do not orbit any star entering the Solar System from without, typically on a collision course with Earth. Less frequently, fictional planets appear in other locations, such as between Venus and Earth or inside a hollow Earth. Similarly, fictional moons appear in some works; fictional additional moons of the Earth largely fell out of favour with the advent of the Space Age.
Planets outside of the Solar System have appeared in fiction since at least the 1850s, long before the first real ones were discovered in the 1990s. Most of these fictional planets do not differ significantly from the Earth, and serve only as settings for the narrative. The majority host native lifeforms, sometimes with humans integrated into the ecosystems. Fictional planets that are not Earth-like vary in many different ways. They may have significantly stronger or weaker gravity on their surfaces, or have a particularly hot or cold climate. Both desert planets and ocean planets appear, as do planets with unusual chemical conditions. Various peculiar planetary shapes have been depicted, including flattened, cubic, and toroidal. Some fictional planets exist in multiple-star systems where the orbital mechanics can lead to exotic day–night or seasonal cycles, while others do not orbit any star at all. More fancifully, planets are occasionally portrayed as having sentience, though this is less common than stars receiving the same treatment or a planet's lifeforms having a collective consciousness.
Pantropy is a hypothetical process of space habitation or space colonization in which, rather than terraforming other planets or building space habitats suitable for human habitation, humans are modified to be able to thrive in the existing environment. The term was coined by science fiction author James Blish, who wrote a series of short stories based on the idea.
The concepts of space stations and space habitats feature in science fiction. The difference between the two is that habitats are larger and more complex structures intended as permanent homes for substantial populations, but the line between the two is fuzzy with significant overlap and the term space station is sometimes used for both concepts. The first such artificial satellite in fiction was Edward Everett Hale's "The Brick Moon" in 1869, a sphere of bricks 61 meters across accidentally launched into orbit around the Earth with people still onboard.
Comets have appeared in works of fiction since at least the 1830s. They primarily appear in science fiction as literal objects, but also make occasional symbolical appearances in other genres. In keeping with their traditional cultural associations as omens, they often threaten destruction to Earth. This commonly comes in the form of looming impact events, and occasionally through more novel means such as affecting Earth's atmosphere in different ways. In other stories, humans seek out and visit comets for purposes of research or resource extraction. Comets are inhabited by various forms of life ranging from microbes to vampires in different depictions, and are themselves living beings in some stories.
Disasters in popular culture includes real and fictional disasters, as depicted by the media, and are considered social events. Disaster movies made in Hollywood are part of the American pop culture. Catastrophe types can include hostile aliens, climate change/global warming, environmental disasters, financial crises, natural disaster, nuclear apocalypse, pandemics, super heros, terrorist attacks, zombies and other technological meltdowns.
The far future has been used as a setting in many works of science fiction. The far future setting arose in the late 19th century, as earlier writers had little understanding of concepts such as deep time and its implications for the nature of humankind. Classic examples of this genre include works such as H.G. Wells' The Time Machine (1895) or Olaf Stapledon's Last and First Men (1930). Recurring themes include themes such as Utopias, eschatology or the ultimate fate of the universe. Many works also overlap with other genres such as space opera, science fantasy or apocalyptic and post-apocalyptic fiction.
The Sun has appeared as a setting in fiction at least since classical antiquity, but for a long time it received relatively sporadic attention. Many of the early depictions viewed it as an essentially Earth-like and thus potentially habitable body—a once-common belief about celestial objects in general known as the plurality of worlds—and depicted various kinds of solar inhabitants. As more became known about the Sun through advances in astronomy, in particular its temperature, solar inhabitants fell out of favour save for the occasional more exotic alien lifeforms. Instead, many stories focused on the eventual death of the Sun and the havoc it would wreak upon life on Earth. Before it was understood that the Sun is powered by nuclear fusion, the prevailing assumption among writers was that combustion was the source of its heat and light, and it was expected to run out of fuel relatively soon. Even after the true source of the Sun's energy was determined in the 1920s, the dimming or extinction of the Sun remained a recurring theme in disaster stories, with occasional attempts at averting disaster by reigniting the Sun. Another common way for the Sun to cause destruction is by exploding, and other mechanisms such as solar flares also appear on occasion.
Impact events have been a recurring theme in fiction since the 1800s.
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