Related topics: nasa , mars , planets
Water
hideWater 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.
For more information about Water, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with liquid water
Scientists find signs of liquid water in Saturn's moon
Space & Earth / Space Exploration
Feb 08, 2010 |
4.9 / 5 (20) |
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(PhysOrg.com) -- Scientists working on the Cassini mission to Saturn have found evidence of liquid water on the planet's icy moon Enceladus, suggesting the possibility of life below its surface.
Researchers offer explanation for the differences between Ganymede and Callisto moons
Space & Earth / Space Exploration
Jan 24, 2010 |
5 / 5 (5) |
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(PhysOrg.com) -- Differences in the number and speed of cometary impacts onto Jupiter's large moons Ganymede and Callisto some 3.8 billion years ago can explain their vastly different surfaces and interior ...
Deep heat powers once-in-a-billion-year volcanoes on icy moon
Space & Earth / Space Exploration
Jan 11, 2010 |
4.6 / 5 (11) |
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(PhysOrg.com) -- New research by Macquarie University planetary scientist Dr Craig O’Neill and US colleague Francis Nimmo has found the answer to an apparent cosmic contradiction.
Goddard scientist's breakthrough given ticket to Mars
Space & Earth / Space Exploration
Jan 05, 2010 |
4.6 / 5 (7) |
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The quest to discover whether Mars ever hosted an environment friendly to microscopic forms of life has just gotten a shot in the arm.
Spectacular Mars images reveal evidence of ancient lakes (w/ Video)
Space & Earth / Space Exploration
Jan 04, 2010 |
5 / 5 (18) |
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Spectacular satellite images suggest that Mars was warm enough to sustain lakes three billion years ago, a period that was previously thought to be too cold and arid to sustain water on the surface, according ...
Icy moons of Saturn and Jupiter may have conditions needed for life
Dec 15, 2009 |
4.8 / 5 (17) |
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(PhysOrg.com) -- Scientists once thought that life could originate only within a solar system's "habitable zone," where a planet would be neither too hot nor too cold for liquid water to exist on its surface. ...
Rare Scottish mineral may indicate life on Mars
Space & Earth / Space Exploration
Dec 10, 2009 |
3.7 / 5 (22) |
7
(PhysOrg.com) -- A team of NASA (National Aeronautics and Space Administration) scientists is looking for clues about life on Mars in an earthy clay mineral found only in Aberdeenshire in Scotland.
3 Questions: Sara Seager on searching for Earth-like planets
Nov 23, 2009 |
3.3 / 5 (3) |
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(PhysOrg.com) -- MIT planetary scientist Sara Seager has been studying exoplanets — planets circling stars other than the sun — for many years.
Taking a Bite of Antarctic Ice
Space & Earth / Space Exploration
Nov 16, 2009 |
3.8 / 5 (6) |
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Scientists with NASA’s IceBite project are heading this week for University Valley, a hanging valley perched more than 1600 feet (more than 1 mile) above sea level in Antarctica’s McMurdo Dry Valleys. Their ...
A Tale of Planetary Woe (w/ Video)
Space & Earth / Space Exploration
Nov 11, 2009 |
4.2 / 5 (11) |
5
Once upon a time — roughly four billion years ago — Mars was warm and wet, much like Earth. Liquid water flowed on the Martian surface in long rivers that emptied into shallow seas. A thick atmosphere blanketed ...
Jupiter's Moon Europa Has Enough Oxygen For Life
Space & Earth / Earth Sciences
Oct 16, 2009 |
4.8 / 5 (102) |
42
New research suggests that there is plenty of oxygen available in the subsurface ocean of Europa to support oxygen-based metabolic processes for life similar to that on Earth. In fact, there may be enough ...
Hot Debate over Icy Moon
Space & Earth / Space Exploration
Oct 08, 2009 |
4.6 / 5 (5) |
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The recent discovery of plumes containing water vapor erupting from the south pole of the frigid Saturnian moon Enceladus set off a firestorm of debate.
It's a grind to make Mars red
Space & Earth / Space Exploration
Sep 18, 2009 |
4.6 / 5 (5) |
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(PhysOrg.com) -- The widespread idea that Mars is red due to rocks being rusted by the water that once flooded the red planet may be wrong. Recent laboratory studies show that the red dust may be formed by ...
Kepler and the Search for Life in Our Galaxy
Sep 15, 2009 |
4.3 / 5 (9) |
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(PhysOrg.com) -- There are so many stars in our galaxy that even if planets with complex life (animals and plants) are rare - say one for every billion stars - there could still be dozens here in the Milky ...
Will Kepler find habitable moons?
Sep 03, 2009 |
5 / 5 (15) |
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(PhysOrg.com) -- Since the launch of the NASA Kepler Mission earlier this year, astronomers have been keenly awaiting the first detection of an Earth-like planet around another star. Now, in an echo of science ...
