Extraterrestrial Life

Extraterrestrial life (from the Latin words: extra and terrestris ) is defined as life that does not originate from Earth. It is often also referred to as alien life, or simply aliens (or space aliens, to differentiate from other definitions of alien or aliens). These hypothetical forms of life range from simple bacteria-like organisms to beings far more complex than humans.

The development and testing of hypotheses on extraterrestrial life is known as exobiology or astrobiology; the term astrobiology, however, includes the study of life on Earth viewed in its astronomical context. Many scientists consider extraterrestrial life to be plausible, but there is no conclusive evidence for its existence. Since the mid-20th century, there has been an ongoing search for signs of extraterrestrial life, from radios used to detect possible extraterrestrial signals, to telescopes used to search for potentially habitable extrasolar planets. It has also played a major role in works of science fiction.

Read more about Extraterrestrial LifeBackground, Possible Basis, Planetary Habitability in The Solar System, Scientific Search, The Drake Equation

Other articles related to "extraterrestrial life, life, extraterrestrial":

Biosignature - In Astrobiology
... the premise that biosignatures encountered in space will be recognizable as extraterrestrial life ... is determined, not only by the probability of life creating it, but also by the improbability of nonbiological (abiotic) processes producing it ... organic molecules and/or structures whose formation is virtually unachievable in the absence of life ...
ALH84001 - Hypothetic Biogenic Features
... when it was claimed that the meteorite may contain evidence of traces of life from Mars, as published in an article in Science by David McKay of NASA ... nanobacteria, but smaller than any known cellular life at the time of their discovery ... of their formation, they would be the first solid evidence of the existence of extraterrestrial life, aside from the chance of their origin being terrestrial contamination ...
The Universe (TV Series) - Episodes - Season 1: 2007
... Mons the largest volcano in the solar system how NASA probes search for evidence of past life on the red planet, and what that life might have looked like 3 ... "E ... Scientists theorize about what sort of life could evolve on these alien worlds 8 ... "Saturn Lord of the Rings" July 24, 2007 (2007-07-24) A look at the planet Saturn and its fascinating rings how they ...
Extraterrestrial Life - Beliefs - Recent History
... Notwithstanding, the belief in extraterrestrial beings continues to be voiced in pseudoscience, conspiracy theories, and in popular folklore, notably "Area 51 ... Donald Brownlee published a book entitled Rare Earth Why Complex Life is Uncommon in the Universe ... the Rare Earth hypothesis, in which they claim that Earth-like life is rare in the Universe, while microbial life is common ...

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