The land surface is shaped by water's movements. Living things need water for survival. Water exists as vapor in the atmosphere and is the stuff of clouds. As a renewable resource, water transforms through three states of matter, solid, liquid, and gas as it cycles from the oceans to the atmosphere, to the land, and back to the oceans. Water and its effects are the dominant features Space Shuttle astronauts see from space.
Water is a powerful force of change.
Among the most destructive forces of nature, hurricanes and typhoons are driven by the Sun's heat and act as a great pressure relief valve for Earth's atmosphere. At this stage in its life, Hurricane Bonnie has a well developed eye where air currents are relatively calm. Window reflections are visible on the right side of the picture. The presence and the absence of water are both clearly seen in this STS-50 view of the Sinai Peninsula from the Nile river into Iraq. The Fayum Depression, the well watered valley of the lower Nile, and the fertile Nile Delta are dark in contrast to the lighter orange and yellow of the surrounding desert.