Do other planets have water?
Directly confirmed results not only come from some planets, but also their moons.
NASA has confirmed that water flows intermittently on the surface of Mars, and that there are two main reservoirs of frozen water at the polar caps of Mars. It is also suspected that a layer of frozen water exists below the surface of Mars.
Spectrometry analysis results have determined that all the Jovian planets, to some extent, contain pressurised water vapour in their atmospheres.
Many non-planetary objects like comets (explaining their tails when approaching and leaving the Sun), meteors and asteroids also have water on them - except in the form of ice, as space is rather cold. Some of the biggest moons in our Solar System are also theorised to have huge lakes (or even oceans) of water beneath their atmospheres.