Amy Fuller, age 9, of Williamsport, Pa., for her question:
WHERE DID WATER COME FROM?
Everyone in North America uses about 70 gallons of water each day in his home. On an average, a person will drink about 16,000 gallons of water during his lifetime.
It has been estimated that only about 3 percent of the earth's water is fresh, and about three fourths of this fresh water is found in the glaciers and icecaps of the north. The glaciers contain as much water as flows in all of the earth's rivers in about 1,000 years.
Many scientists tell us the earth was formed from materials that came from the sun. In these materials were the elements that make up water. As the earth cooled and grew solid, water was trapped in rocks in the earth's crust. Gradually the water was released and filled the ocean basins.
There is a continuous movement of water from the oceans, to the air, to the land and then back to the oceans again. Heat from the sun evaporates water from the oceans. The water then rises as invisible vapor and falls back to earth as rain, snow or some other form of moisture.
The unending circulation of the earth's waters is called the water cycle, or hydrologic cycle.
There's as much water on earth today as there ever was or ever will be. Scientists tell us that the glass of water on your dinner table last night might have been flowing down the Nile River last month. And it could well be the same water that was served on a dinner table in ancient Rome 2,000 years ago.
About 70 percent of the earth's surface is covered with water. Your body is about 65 percent water, and about 70 percent of an ear of corn is water. Water makes up about 80 percent of a potato and about 95 percent of a tomato.
Without water there could be no life. Every living thing must have water to carry out its life processes. Plants and animals as well as humans use watery solutions to help dissolve food substances and carry nutrients to all parts. Water plays an important part in every organism's growth and development.
There's a lot of water on earth. It is estimated that there are about 326 million cubic miles of the wet stuff around. That figures to a million million gallons.
About 97 percent of the world's water is found in the oceans, and all of it is salty. Two percent of the world's water is in icecaps and glaciers, which leaves a 1 percent total for all the lakes, springs, rivers, pools, ponds and underground deposits.