Water is life! Every living thing depends upon it and about 60% of the human body is water! Man has failed to find any significant amounts of water anywhere else in the universe yet 70% of our planet is covered with water, thus making it unique.
Water is different to virtually all other liquids. These become denser as they become colder and so sink to the bottom. Water on the other hand, grows denser as the temperature falls to 4%C but then it suddenly starts getting lighter so that the ice floats on top! If this were not the case all living things below the surface would die. How could such a wonderful process have happened accidentally?