Glossary term: 地外生命
Description: 地外生命或外星生命是指可能出現在地球之外且未在地球上起源的生命形式。
儘管迄今為止尚未發現簡單形式的地外生命，但在我們銀河系的數十億顆系外行星上，生命的產生是可能的。據天文學家估計，在我們銀河系中的平均每顆恆星都有一個以上的行星。其中一些系外行星可能能提供與地球上生命出現時相似的條件，特別是液態水。
正如在地球上一樣，某些種類生命的存在可能會顯著改變這種行星大氣的化學成分，因此天文學在未來幾十年的一個主要目標就是通過研究遙遠行星的大氣來探測生命的存在。另一方面，尋找地外智慧生命（SETI）項目長期以來一直在尋找其他世界上智慧生命可能發出的無線電信號。在我們的太陽系中，木星的衛星木衛二和土星的衛星土衛二的冰封海洋中可能存在生命。
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Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher The translation of this term and its definition is still awaiting approval
This is an automated transliteration of the simplified Chinese translation of this term
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