Extraterrestrial liquid water, the presence of water in its liquid state, is a subject of wide interest because it is commonly believed to be a prerequisite for extraterrestrial life.
Earth, with oceanic water covering 71% of its surface, is the only planet known to have stable bodies of liquid water on its surface and liquid water is essential to all life on Earth. Earth orbits the center of the Sun's habitable zone, a region in which liquid water can exist on the surface of a planet with sufficient atmospheric pressure.
There is growing evidence of liquids below the surface of several natural satellites and dwarf planets elsewhere in the Solar System that may consist of liquid water, some are speculated to be large "oceans"; however, none have been confirmed. Oceans and water may be common in other planetary systems; for example, water vapour was found in 2007 in the proplanetary disc of a young star MWC 480, within 1 AU of the star.
Surface water was once thought to cover large areas of Venus and Mars and possible seasonal flows on warm Martian slopes have been observed since 2008.
Other articles related to "extraterrestrial liquid water":
... Among the 1,235 possible extrasolar planet candidates detected by NASA's planet-hunting Kepler space telescope during its first four months of operation, 54 are orbiting in the parent star's habitable 'Goldilocks' zone where liquid water could exist ... Five of these are near Earth-size, and the remaining 49 habitable zone candidates range from twice the size of Earth to larger than Jupiter ...
Famous quotes containing the words water and/or liquid:
“Id take off all my clothes
& cross the damp cold lawn & down the bluff
into the terrible water & walk forever
under it out toward the island.”
—John Berryman (19141972)
“Tomorrow night, when Phoebe doth behold
Her silver visage in the watery glass,
Decking with liquid pearl the bladed grass.”
—William Shakespeare (15641616)