"The most unmistakable chemical transformation is that of a matter's state – a solid liquefies, a liquid evaporates, a vapor condenses into rain. For most of the furnishings of our everyday life, we associate a particular substance with only one of those three states. Wood, steel, and stone – solid. Oxygen and helium – gas. Alcoholic beverages – liquid (you can keep a bottle of Bombay Sapphire in the freezer, and somehow it remains an ever pourable starter to a gin and tonic). Water again bucks convention and seems almost equally at home in all three forms, as ice, steam, and liquid. In fact, Earth is exceptional in its possession of tristate water. Mars has a lot of water, but it's frozen away underground. Jupiter and Saturn have traces of water, too, but as orbiting ice crystals or a gas among miasmic gases. Only on Earth are there ocean flows and Arctic floes and sputtering Yellowstone fumaroles; only the Goldilocks planet has water to suit every bear."
– Natalie Angier, The Canon: A Whirligig Tour of the Beautiful Basics of Science