Life

:For other uses, see Life and Living

The possibility of extraterrestrial life

Main articles: Extraterrestrial life, Astrobiology

Related Topics:
Extraterrestrial life - Astrobiology

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As of 2005, Earth is the only planet in the universe known by humans to support life. The question of whether life exists elsewhere in the universe remains open, but analyses such as the Drake equation have been used to estimate the probability of such life existing. There have been a number of claims of the discovery of life elsewhere in the universe, but none of these have yet survived scientific scrutiny.

Related Topics:
As of 2005 - Earth - Universe - Drake equation

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Today, the closest that scientists have come to finding extraterrestrial life is fossil evidence of possible bacterial life on Mars (via the ALH84001 meteorite). Searches for extraterrestrial life are currently focusing on planets and moons believed to possess liquid water, at present or in the past. Recent evidence from the NASA rovers Spirit and Opportunity supports the theory that Mars once had surface water. See Life on Mars for further discussion.

Related Topics:
Bacteria - Mars - ALH84001 - Spirit - Opportunity - Life on Mars

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Jupiter's moons are also considered good candidates for extraterrestrial life, especially Europa, which seems to possess oceans of liquid water.

Related Topics:
Jupiter - Europa

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Other highly (and somewhat doubtful) speculative places for present or past life include atmosphere of Venus, Titan cyrovolcanoes, or even Enceladus.

Related Topics:
Venus - Titan - Enceladus

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