What is Extraterrestrial life?
'''Extraterrestrial life''' is [[life]] that is not from the [[planet]] [[Earth]]. It is also called '''alien life''' or just '''extraterrestrials''' or '''aliens'''. The word '[[Earth|''Terra'']]' in [[Latin]] refers to our [[planet]] - [[Earth]]. Thus, extraterrestrial life refers to the [[Organism|life forms]] not originating on or from the [[planet]] [[Earth]]. It is reasonable to say that [[planets]] rather like ours exist, and that life might [[evolve]] there also. So far, none has been found, though it is possible that life once existed on [[Mars]].<ref>Sagan, Carl & Shklovskii I.S. 1966. ''Intelligent life in the Universe''. Random House.</ref> It is not a new idea. Some [[philosopher]]s have speculated on the existence of other planets like ours, with the idea that what happened here could also happen there.<ref>Crowe, Michael J. 1986. ''The Extraterrestrial life debate, 1750–1900. Cambridge. {{ISBN|0-521-26305-0}}''</ref><ref>Crowe, Michael J. 2008. The extraterrestrial life debate Antiquity to 1915: a source book. University of Notre Dame Press. {{ISBN|0-268-02368-9}}</ref> One thing we do know is that many other [[star system]]s have [[exoplanets]]. Searches like [[SETI]] have been made for [[signals]] from extraterrestrial life-forms.<ref>Sagan, Carl 1973. ''Communication with extraterrestrial intelligence''. MIT Press. {{ISBN|0-262-19106-7}}</ref> No clear signals from outer space have been detected yet. ==In fiction== [[File:The War of the Worlds by Warwick Goble 39.jpg|thumb|A drawing of [[Mars in fiction|Martians]] from [[The War of the Worlds]]]] Alien life is commonly seen in [[Science fiction]] and some [[Fantasy]]. Aliens in fiction are frequently shown as looking a lot like [[Human|humans]], but some [[Author|authors]] have created much stranger aliens. [[H. P. Lovecraft|H.P. Lovecraft]], [[Kurt Vonnegut]], and [[H. G. Wells|H.G. Wells]] all wrote about aliens that look very different than humans. ==In religion== {{main article|UFO religion}} Some [[Religion|religions]] believe in al