Extraterrestrial liquid water

Common card · No. 355068

Extraterrestrial liquid water is water in its liquid state that naturally occurs outside Earth. It is a subject of wide interest because it is recognized as one of the key prerequisites for life as we know it and is thus surmised to be essential for extraterrestrial life. Although many celestial bodies in the Solar System have a hydrosphere, Earth is the only celestial body known to have stable bodies of liquid water on its surface, with oceanic water covering 71% of its surface, which is essential to life on Earth. The presence of liquid water is maintained by Earth's atmospheric pressure and stable orbit in the Sun's circumstellar habitable zone; however, the origin of Earth's water remains uncertain. The main methods currently used for confirmation are absorption spectroscopy and geochemistry. These techniques have proven effective for atmospheric water vapor and ice. However, using current methods of astronomical spectroscopy it is substantially more difficult to detect liquid water...

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