Although water is all about us, seen and unseen, we still find it mysterious and, in many ways, one of the least understood of all our natural resources.

The Earth is a watery planet, with most of its surface covered with oceans and seas. The presence of large amounts of water makes our planet unique in the solar system, probably the only one capable of sustaining life. The nature of water makes it essential to life, and the nature of life makes it dependent on water. If we should someday discover life outside our solar system, it will most likely be on another watery planet similar to ours.