Whether or not we are alone in the universe is one of life’s greatest mysteries. On Earth we find ourselves in the “Goldilocks Zone,” which means that conditions are just right for hosting life, but we have discovered other Earth-like planets deep in space, as well as planets that are thought to have water (which could, of course, lead to life). When discussing the possibility of extraterrestrial life, often we are talking about any form of life and not necessarily an advanced race, but there are certainly reasons to believe that we are not alone out there.
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