|The woo is out there|
|Aliens did it...|
|... and ran away|
“”The gods watch over us and guide our destinies, many human cultures teach; other entities, more malevolent, are responsible for the existence of evil. Both classes of beings, whether considered natural or supernatural, real or imaginary, serve human needs. Even if they're wholly fanciful, people feel better believing in them. So in an age when traditional religions have been under withering fire from science, is it not natural to wrap up the old gods and demons in scientific raiment and call them aliens?
|—Carl Sagan, The Demon-Haunted World|
"Extraterrestrial" ("ET") describes any object or being beyond the planet Earth; "an extraterrestrial" almost invariably refers to other life forms, also known as EBEs (Extraterrestrial Biological Entities).
Because of the sheer scale of the cosmos, the possibility that we are the only form of life in the entire universe is remote; therefore some form of life is likely to exist elsewhere on other planets, natural satellites, planetary-mass objects and brown darfs.
Fairly primitive life, such as bacteria, has been hypothesized by scientists such as Carl Sagan to even exist elsewhere in our own solar system, although no reliable evidence for this has been found. More advanced life is likely to have formed outside the solar system and many people — kooks and rational thinkers alike — are convinced that it's out there just waiting to be found.
Based on the anecdotes and "research" of ufologists and abductees over the last 50 years or so, one thing is absolutely clear — that, while we can let our imaginations get the best of us, the truth is our imaginations are not even that good at actually being original.
 Intelligent extraterrestrial life
The narrower and arguably more common definition of "extraterrestrial" is "an intelligent life form that is of extraterrestrial origin" — an alien, in other words. Normally they are thought of as aliens who visit this planet, for whatever reason that aliens might want to visit this planet. This is a pretty cool idea because, assuming communication is even possible with such beings, it would afford the opportunity to compare observations about the nature of reality. This is also cool because, along with spaceships and laser guns, the encounter with aliens is every nerd's dream. As such it is the subject to a lot of crackpot thinking and conspiracy theories. These beliefs range from aliens communicating telepathically with people — similar to mediums talking to the dead — to deliberate coverups by world governments and reverse engineering of alien technology. Despite the prevalence of such beliefs, and the fantastic and attractive narratives that they produce, they are most likely completely and utterly bullshit. No convincing evidence has ever been found in favor of the existence of such beings, let alone the idea that they may be on Earth right now.
Claims that some UFOs are of extraterrestrial origin and claims of alien abduction have not been substantiated and both phenomena can be easily and simply explained without invoking little green men with anal probes. Firsthand accounts of interactions with ET's tend to be anecdotal and often unreliable with little or no physical evidence presented. As a result, investigation of alien encounters by science is difficult. Since ET's seem reluctant to do their abductions near anyone appropriately equipped to document them, we have no hard evidence or reason to believe that they are on Earth interacting with us on a near daily basis.
Or maybe they just don't live nearby? Or maybe they just don't like us enough to talk to us
face to face face to tentacle? Extraterrestrials, it seems, are still confined to the world of science fiction and wildly entertaining conjecture by exobiologists.
 Drake Equation
The Drake Equation is an attempt to quantify the likelihood of alien civilizations being capable of communicating with humans on Earth. Named after radio astronomer Frank Drake, it contains a number of variables such as number of stars in a galaxy, number of planets suitable for life, etc. An interactive version can be found here.
One of the main issues with the Drake Equation is the estimated life span of any advanced civilization, i.e., once it becomes advanced enough to communicate, how long before it blows itself up? While any value for this is necessarily speculative (we're dealing with a sample size of zero, since our only example is our own society, which we can't know how long will last), Drake's original estimate for this value is 10,000 years, while a more modern approach by Michael Shermer set it to only 420 years. This means that any signal received from space (given the enormous distances between stars) could well be from an already long-dead civilization.
 The usual suspects
 What we know so far
The aliens that have supposedly come to Earth have been described as appearing in many different forms. This indicates either that planet Earth is improbably interesting to several varieties of aliens — or that the reports themselves are the result of hyperactive human imaginations.
At the same time, the spectrum of described alien appearances — differing enough from each other to qualify as separate species — is populated by examples of aliens that are all generally anthropomorphic (and even outright humanoid) enough to be quite similar not just to us, but to each other. With minor variance, we're talking: the same amount of arms, legs, mouths (save for the Xenomorph), eyes, ears and so on. This implies that they might all share an evolutionary timeline — and for that to be true, they'd basically all have to originate from the same planet.
Consider it — all those species of aliens look attuned for kind of the same gravities and temperatures, and approximate the appearances of each other much closer than we approximate the appearance of lots of animals here on Earth. Note also that we approximate the appearance of the aliens — and vice versa — in just the same way.
So, did they all come here from the same planet on separate missions, unaware of each other...? Are they perhaps part of some epic
space opera galactic war, and we're thrown smack-dab in the middle of it, as if taken right out of TVtropes? Actually, since they're so humanoid, and so attuned to earthly conditions — never mind often described as having the ability (and desire) to have sex with humans (!) — it is actually far more likely that they originate from Earth. A result of that, however, is that it's more likely still that they originate from the imaginations of creatures from Earth.
Interestingly, all species of aliens are consistently described as being about the size they'd have to be in order to be able to interact with us in a way that we humans find meaningful — never disappearingly small, never the size of Godzillas. Why, it's almost as if they were imagined by us in the only way that enables them be cast in exciting and interactive roles by the human imagination.
In fact, there is often a good correlation between the culture describing the aliens and what said culture claims the aliens look like. The "Grey" species is undoubtedly the most commonly imagined and the most commonly depicted in fiction, from Close Encounters of the Third Kind to the Asgard from Stargate. Essentially not different from the elves or orcs of fantasy, in that they're basically humans with caricatured features — and what's more, the features are supposed to represent their qualities. The noble and eloquent elves — humans that all look like models. The proud and mighty orcs — humans that all look like Kali Muscle.
The childlike Greys with their big eyes and big heads (presumably containing big brains), yet slender and weak limbs, come off as observant, intelligent and techonological. They're clearly tool users, since we don't imagine them surviving in the wild without tools. Since we imagine the wilds on their planet to be like the wilds on Earth. Since we imagine that their home planet has about the same amount of gravity, the same temperature range and similar gas distribution to Earth. Since we imagine that the evolution of life looks about the same everywhere. Since we imagine that all life is carbon-based to begin with. And who ever said you can't travel faster than light, anyways?!
The dreadful Xenomorphs, on the other hand, don't look like tool users. They don't look technological. I mean, ask yourself. How would they fit into a cockpit and operate pedals and stuff? And besides, they don't use tools in the movies. They don't wear armor, they're born armored. They don't wield weapons, they are a weapon. Like the predators we've evolved to fear — snakes and tigers and the likes — the Xenomorphs rely on their senses. Yeah — they're born fully decked killing machines. And from eggs, too — eew. They don't look social. They look like lone hunters who predate upon soft-bellied, social animals like ourselves. Yeah. And that definitely means they can't have tool use. Besides, they don't have the temper for it. Because we know it takes social, vaguely ape-like vertebrates to ever have tool use. Right?
Now, you might object — the Xenomorphs are fictional! Boy, do we have news for you...
Similarly, the "flying saucer" shape only became prevalent after UFOs were reported as being "saucer-like", which people misinterpreted as being a description of shape, rather than how they moved through the sky. Some early close encounters reported dart-shaped or cigar-shaped rather than saucer-shaped UFOs, before the saucer meme became predominant.
 The alien zoo
Either way, "respected" scholars have identified several different species of alien. They include:
- Greys: These are the most famous popular aliens. They are short and have really big heads, no hair, grey skin, either very small or no mouth and nose, and really big eyes. They are the most commonly reported aliens in North America. They seem to have an agenda, but the grey agenda should not be confused with the gay agenda (although both seem to involve anal probing).
- Nordics: These look like a Nazi's wet dream, although taller and not so into Hitler. For some reason, they like to abduct Europeans more than Americans.
- Reptilians: Also known as the Gorn, they look like sentient dinosaurs. Like the Greys, they too have an agenda, theirs involving the shadow conquest of Earth. David Icke and his followers believe that Queen Elizabeth, the Bush family, and nearly every other major politician is actually a reptilian in disguise. Seems reasonable enough.
- Designers: Also known as the Elohim (singular Elohah), they look exactly like a small version of a Japanese person because, according to Raelians, they made us in their image. They also gave messages to different populations through religious figures like the Buddha, Jesus, Muhammad, and Moses.
- Pleiadians: They really care about us and are into multi-dimensional physics.
- Rods: Ufologists disagree as to whether these are aliens or spacecraft; more sensible people agree that they are moths.
- Thetans: Originally alien citizens of various species who lived 75 billion years ago, until they were thrown into volcanoes on Tegeeack (also known as "Earth" to sane people) which then had hydrogen bombs detonated inside of them by the Galactic Overlord Xenu. Thus the restless, wandering alien souls, known as Thetans, were created, in the billions, right here on Earth. Ever since, these parasitic alien spirits have spent most of their time attaching themselves to us, and if only we'd read Dianetics, we'd be able to relieve our selves both of these invaders and of large quantities of cash in one fell swoop. Visit your local Church of Scientology center today to learn more, and get the opportunity to sign over your house to the Church - soon to be the new local recruitment center!
Sadly for those who believe in these fantasy people, there is no actual reliable evidence for any of them, as their existence is based solely on people's personal testimony, which is frankly useless. There was a very close call when footage of an autopsy was "leaked" in the 1990s, but this was revealed to be a hoax far too soon for it to be any fun.
 Contact with Earth
Some of the aliens' favorite hobbies while on our planet include:
- Building the Giza pyramids
- Making crop circles
- Abducting Texans for bizarre sexual experiments
- Using their "flying saucers" to buzz unsuspecting drivers, often in, again, Texas
- Taking our jobs and sponging off our welfare systems
- Hollowing out the Earth to build their secret bases
- Eating the dinosaurs
- Mutilating cattle
- Anal Probing
In November 2011, the United States White House officially stated that the US (and as far as they knew, no other country) has never had contact with alien life. Of course, they also said they do not know who shot Kennedy; it's apparent who's lying, isn't it?
 In a nutshell
 See also
- Alien abduction
- Alien invasion
- The Brookings Report
- Fermi paradox
- Heaven's Gate
- Intervention theory
- Unidentified flying object
- Real Grey Alien Pictures and Videos – All about the greys
- AlienResistance.Org – Another fine example
- Message from the Designers – This website claims that extraterrestrials somehow designed us and gave us messages via religious leaders
- ↑ Atmospheric Habitable Zones in Y Dwarf Atmospheres
- ↑ http://www.theatlantic.com/video/index/506846/were-probably-imagining-aliens-wrong/
- ↑ 'No evidence' for extraterrestrials, says White House Or is that part of a cover-up?
- ↑ Michael Shermer - Why hasn't ET called?
- ↑ We apologize to our future alien overlords who may be reading this at a later date.
- ↑ Just to pick one example — Greys and Xenomorphs share way more features than humans and ocean sunfish do, or humans and crystal butterflies do, or humans and blue angels do. C'mon guys.
- ↑ David Icke has a solution to this problem, however — turns out, we're all actually aliens! Or, descended from aliens. Or related to aliens. Or something.
- ↑ So still — technically — from Earth. What??
- ↑ $10 worth of latex makeup completes the comparison. Imagine applying it a little differently and maybe changing the color to green — you'd have most fantasy orcs in a heartbeat.
- ↑ Bursting from people's stomachs, by extension. So fresh you can taste the crunch!
- ↑ Well, we gotta have some way of beating them! They can be born terminators — but damnit, they can't be intellectuals as well! That would ruin the drama of the story, just like if Batman killed the Joker! ...Wait, did I just make a huge point regarding aliens in general?
- ↑ THEY'RE ALL FICTIONAL!
- ↑ See the "UFO to flying saucer" segment of our article on UFOs.
- ↑ We use that term very loosely — it really just means "Respected by other cranks) ufologists".
- ↑ http://memory-alpha.org/en/wiki/Gorn
- ↑ The universe is actually only about 13.8 billion years old
- ↑ Skeptical Enquirer - “Alien Autopsy” Hoax