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#[[Mars]], as mentioned above, is the most popular candidate. Ice is known to exist at the poles. Some liquid water might exist on Mars because temperatures occasionally rise above freezing.

#[[Mars]], as mentioned above, is the most popular candidate. Ice is known to exist at the poles. Some liquid water might exist on Mars because temperatures occasionally rise above freezing.

#The [[Jupiter|Jovian]] moon [[Europa]] is covered with a thick sheet of ice. Scientists speculate that a liquid ocean may exist under the crust and that may harbour life.

#The [[Jupiter|Jovian]] moon [[Europa]] is covered with a thick sheet of ice. Scientists speculate that a liquid ocean may exist under the crust and that may harbour life.

#[[Titan]], a moon of [[Saturn]], has approximately the same percentage of [[nitrogen]] in its atmosphere as in Earth's. Titan also has [[ocean]]s and thick clouds. Scientists have determined that the oceans are liquid [[methane]], not water, and that the low temperatures of -178 Celcius make life, at least as we know it, highly improbable.

#[[Titan]], a moon of [[Saturn]], has approximately the same percentage of [[nitrogen]] in its atmosphere as in Earth's. Titan also has [[ocean]]s and thick clouds. Scientists have determined that the oceans are liquid [[methane]], not water, and that the low temperatures of -178° Celsius make life, at least as we know it, highly improbable.

=== Extraterrestrial Civilizations ===

=== Extraterrestrial Civilizations ===