Astrobiology is a scientific field within the life and environmental sciences that studies the origins, early evolution, distribution, and future of life in the universe by investigating its deterministic conditions and contingent events. As a discipline, astrobiology is founded on the premise that life may exist beyond Earth.
The Drake equation is a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy.
Extraterrestrial life, alien life, or colloquially simply aliens is life which does not originate from Earth. No extraterrestrial life has yet been conclusively detected. Such life might range from simple forms such as prokaryotes to intelligent beings, possibly bringing forth civilizations that might be far more advanced than humanity. The Drake equation speculates about the existence of sapient life elsewhere in the universe. The science of extraterrestrial life is known as astrobiology.
The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, "If life is so easy, someone from somewhere must have come calling by now."
Krypton is a fictional planet appearing in American comic books published by DC Comics, most commonly appearing or mentioned in stories starring the superhero Superman as the world from whence he came. The planet was created by Jerry Siegel and Joe Shuster, and was named after the chemical element krypton. The planet was first mentioned in Action Comics #1 and made its first appearance in Superman #1 (1939).
SimEarth: The Living Planet is a life simulation game, the second designed by Will Wright. and published in 1990 by Maxis. In SimEarth, the player controls the development of a planet. English scientist James Lovelock served as an advisor and his Gaia hypothesis of planet evolution was incorporated into the game. Versions were made for the Macintosh, Atari ST, Amiga, IBM PC, Super Nintendo Entertainment System, Sega CD, and TurboGrafx-16. It was re-released for the Wii Virtual Console. In 1996, several of Maxis' simulation games were re-released under the Maxis Collector Series with greater compatibility with Windows 95 and differing box art, including the addition of Classics beneath the title. SimEarth was re-released in 1997 under the Classics label.
The concept of self-replicating spacecraft, as envisioned by mathematician John von Neumann, has been described by futurists and has been discussed across a wide breadth of hard science fiction novels and stories. Self-replicating probes are sometimes referred to as von Neumann probes. Self-replicating spacecraft would in some ways either mimic or echo the features of living organisms or viruses.
E.V.O.: Search for Eden is a 1992 action-adventure game developed by Almanic Corporation and published by Enix for the Super NES. Combining traditional platforming mechanics with experience and leveling mechanics originating from role playing games, E.V.O.: Search for Eden involves the player navigating a creature through a number of side-scrolling levels while undergoing bodily evolution to cope with ever-changing environments. It is heavily based on Almanic's original title, 46 Okunen Monogatari ~The Shinka Ron~, released in Japan in 1990 for the PC-9801.
The High Evolutionary is a fictional character appearing in American comic books published by Marvel Comics. He is depicted as a scientist who seeks to evolve different life forms such as the New Men. The High Evolutionary's goals have often put him at odds with different superheroes.
The Celestials are fictional characters appearing in American comic books published by Marvel Comics. Depicted as cosmic beings, they debuted in the Bronze Age of Comic Books and have reappeared on numerous occasions.
In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity such as sexually reproducing, multicellular organisms on Earth required an improbable combination of astrophysical and geological events and circumstances.
The zoo hypothesis speculates on the assumed behavior and existence of technologically advanced extraterrestrial life and the reasons they refrain from contacting Earth. It is one of many theoretical explanations for the Fermi paradox. The hypothesis states that alien life intentionally avoids communication with Earth to allow for natural evolution and sociocultural development, and avoiding interplanetary contamination, similar to people observing animals at a zoo. The hypothesis seeks to explain the apparent absence of extraterrestrial life despite its generally accepted plausibility and hence the reasonable expectation of its existence. A variant on the zoo hypothesis suggested by the former MIT Haystack Observatory scientist John Allen Ball is the "laboratory" hypothesis, in which humanity is being subjected to experiments, with Earth serving as a giant laboratory.
Ego the Living Planet is a fictional character appearing in American comic books published by Marvel Comics. The character first appeared in Thor #132 and was created by writer Stan Lee and artist Jack Kirby.
Alien Planet is a 2005 docufiction TV special created for the Discovery Channel. Based on the 1990 book Expedition by the artist and writer Wayne Barlowe, Alien Planet explores the imagined extraterrestrial life of the fictional planet Darwin IV in the style of a nature documentary. Although closely following Barlowe's depiction of Darwin IV, Alien Planet features a team of scientists and science fiction figures discussing Darwin IV as if it had actually been discovered. Among the people featured are Michio Kaku, Stephen Hawking, Jack Horner, James B. Garvin and George Lucas.
Planetary habitability is the measure of a planet's or a natural satellite's potential to develop and maintain environments hospitable to life. Life may be generated directly on a planet or satellite endogenously or be transferred to it from another body, through a hypothetical process known as panspermia. Environments do not need to contain life to be considered habitable nor are accepted habitable zones (HZ) the only areas in which life might arise.
Extraterrestrial is a British-American two-part television documentary miniseries, aired in 2005 in the UK by Channel 4, by the National Geographic Channel in the US on Monday, May 30, 2005 and produced by Big Wave Productions Ltd. The program focuses on the hypothetical and scientifically feasible evolution of alien life on extrasolar planets, providing model examples of two different fictional worlds, one in each of the series's two episodes.
"Green Patches" is a science fiction short story by American writer Isaac Asimov. It was first published in the November 1950 issue of Galaxy Science Fiction under the title "Misbegotten Missionary", and reprinted under that title in the 1952 anthology Tomorrow, the Stars. It was retitled "Green Patches" in Asimov's 1969 collection Nightfall and Other Stories.
There is evidence that the formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed.
The Kroloteans are a fictional extraterrestrial race existing in the DC Universe. They first appear in Green Lantern #4.
Ex Nihilo is a fictional character appearing in American comic books published by Marvel Comics.
