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TSU physicists are investigating the effects of radiation on DNA

Scientists from TSU's Laboratory of Experimental High Energy Physics and their colleagues from the University of Bordeaux are studying new ways of modeling the effects of low doses of radiation at the cellular level. For ...

How Venus and Mars can teach us about Earth

One has a thick poisonous atmosphere, one has hardly any atmosphere at all, and one is just right for life to flourish – but it wasn't always that way. The atmospheres of our two neighbours Venus and Mars can teach us a ...

Why we always spill tea

Who has never spilled water, tea or wine while pouring it? Pouring liquids is difficult because they tend to cling to the bottle or the teapot spout rather than flowing directly into your cup or glass. A team of scientists ...

Scientists find likely source of methane on Mars

The mystery of methane on Mars may finally be solved as scientists Monday confirmed the presence of the life-indicating gas on the Red Planet as well as where it might have come from.

Putting a new spin on Majorana fermions

The combination of different phases of water—solid ice, liquid water, and water vapor—would require some effort to achieve experimentally. For instance, if you wanted to place ice next to vapor, you would have to continuously ...

Rivers raged on Mars late into its history

Long ago on Mars, water carved deep riverbeds into the planet's surface—but we still don't know what kind of weather fed them. Scientists aren't sure, because their understanding of the Martian climate billions of years ...

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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.

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