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Posted by on Sep 16, 2017 in Tell Me Why | 0 comments

Does Extraterrestrial Life or so Called Aliens Actually Exist?

Does Extraterrestrial Life or so Called Aliens Actually Exist?

Unless you’ve personally had a UFO sighting (and I’d be concerned for your well-being if you have), then you’d know that there’s no proof that aliens (as in the beings we see in many a sci-fi movie) exist. That doesn’t mean that they don’t though, because I totally believe life exists on other planets. I mean we can’t be the only ones out there. So really, you could answer this based on current, scientific proof, or you could teach your kid to believe that there could potentially be aliens in our universe.

Extraterrestrial life, also called alien life (or, if it is a sentient or relatively complex individual, an “extraterrestrial” or “alien”), is life that does not originate from Earth. These hypothetical life forms may range from simple single-celled organisms to beings with civilizations far more advanced than humanity. The Drake equation speculates about the existence of intelligent life elsewhere in the universe. The science of extraterrestrial life in all its forms is known as exobiology.

alien

Since the mid-20th century, there has been an ongoing search for signs of extraterrestrial life. The search encompasses a search for current and historic extraterrestrial life, and a narrower search for extraterrestrial intelligent life. Reflecting the category of search, methods range from the analysis of telescope and specimen data to radios used to detect and send signals of communication.

The concept of extraterrestrial life, and particularly extraterrestrial intelligence, has enjoyed a major cultural impact, chiefly including works of science fiction. Over the years, science fiction both communicated scientific ideas and influenced public interest and perspectives of extraterrestrial life. One shared space is the debate over the wisdom of attempting communication with possible extraterrestrial intelligence: Some encourage aggressive methods to try for contact with intelligent extraterrestrial life, whereas others argue that it might be dangerous to actively call attention to Earth.

Alien life, such as microorganisms, has been hypothesized to exist in the Solar System and throughout the universe. This hypothesis relies on the vast size and consistent physical laws of the observable universe. According to this argument, made by scientists, such as Carl Sagan and Stephen Hawking, as well as well-regarded thinkers, such as Winston Churchill, it would be improbable for life not to exist somewhere other than Earth.

This argument is embodied in the Copernican principle, which states that Earth does not occupy a unique position in the Universe, and the mediocrity principle, which states that there is nothing special about life on Earth. The chemistry of life may have begun shortly after the Big Bang, 13.8 billion years ago, during a habitable epoch when the universe was only 10–17 million years old. Life may have emerged independently at many places throughout the universe.

Alternatively, life may have formed less frequently, then spread—by meteoroids, for example—between habitable planets in a process called panspermia. In any case, complex organic molecules may have formed in the proto-planetary disk of dust grains surrounding the Sun before the formation of Earth. According to these studies, this process may occur outside Earth on several planets and moons of the Solar System and on planets of other stars.

habitable zones

Since the 1950s, scientists have argued the idea that “habitable zones” around stars are the most likely places to find life. Numerous discoveries in these zones since 2007 have generated estimations of frequencies of Earth-like planets —in terms of composition— numbering in the many billions though as of 2013, only a small number of planets have been discovered in these zones.

Nonetheless, on 4 November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs in the Milky Way, 11 billion of which may be orbiting Sun-like stars. The nearest such planet may be 12 light-years away, according to the scientists. Astrobiologists have also considered a “follow the energy” view of potential habitats.

Content for this question contributed by Candy Cloud, resident of Muskegon, Muskegon County, Michigan, USA