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Five facts to help you understand sea ice

One way that scientists monitor climate change is through the measure of sea ice extent. Sea ice extent is the area of ice that covers the Arctic Ocean at a given time. Sea ice plays an important role in reflecting sunlight ...

Titan's river maps may advise Dragonfly's sedimental journey

With future space exploration in mind, a Cornell-led team of astronomers has published the final maps of Titan's liquid methane rivers and tributaries—as seen by NASA's late Cassini mission—so that may help provide context ...

Scientists use seasons to find water for future Mars astronauts

An international team of researchers has used seasonal variations to identify likely sub-surface deposits of water ice in the temperate regions of Mars where it would be easiest for future human explorers to survive. The ...

Martian snow is dusty, could potentially melt, new study shows

Over the last two decades, scientists have found ice in many locations on Mars. Most Martian ice has been observed from orbital satellites like NASA's Mars Reconnaissance Orbiter. But determining the grain size and dust content ...

Florida mayor urges water limits because of COVID-19 surge

The mayor of the Florida city of Orlando asked residents on Friday to stop watering their lawns and washing their cars immediately, saying water usage needed to be cut back because of the recent surge of COVID-19 hospitalizations.

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Water

Water is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.

Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.

Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.

This text uses material from Wikipedia, licensed under CC BY-SA