Where there is water there is life. But why? What makes water such an essential part of the greatest technology ever: life?
Life as we know it on Earth is separated from its environment by a membrane. It needs to be able to take in energy and protect itself from toxic waste.
Water is liquid at most temperatures on Earth, and it is able to dissolve nearly anything. Water also transitions from gas to liquid to solid in a relatively small range of temperatures. Because it dissolves substances easily and flows, it is efficient at transporting substances in and out of cells.
Water is so efficient at this transport function because of its chemical configuration. A negative O(xygen) atom and two positive H(ydrogen) atoms form a polarized molecule, which easily catch other molecules.