Earth's atmosphere
hideThe Earth's atmosphere is a layer of gases surrounding the planet Earth that is retained by the Earth's gravity. It has a mass of about five quadrillion metric tons. Dry air contains roughly (by volume) 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, and trace amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night.
There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades into space. An altitude of 120 km (75 mi) marks the boundary where atmospheric effects become noticeable during atmospheric reentry. The Kármán line, at 100 km (62 mi), is also frequently regarded as the boundary between atmosphere and outer space. Three quarters of the atmosphere's mass is within 11 km (6.8 mi; 36,000 ft) of the surface.
For more information about Earth's atmosphere, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with air
Californians -- and their cell phones -- will help computer scientists monitor air pollution
Technology / Computer Sciences
Dec 04, 2009 |
1 / 5 (2) |
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You want to go for a run, but you don't want to run in polluted air that might aggravate your asthma. University of California, San Diego computer scientists are creating a network of environmental sensors ...
Research shows some plants can remove indoor pollutants
Dec 02, 2009 |
4.7 / 5 (15) |
2
(PhysOrg.com) -- Some plants have the ability to drastically reduce levels of indoor pollutants, according to new research at the University of Georgia. Researchers showed that certain species can effectively ...
Hydrogen-Powered Ion Tiger Sets 26-hour Flight Endurance Record
Nov 30, 2009 |
4.1 / 5 (7) |
2
The Naval Research Laboratory's Ion Tiger, a hydrogen-powered fuel cell unmanned air vehicle (UAV), has flown 26 hours and 1 minute carrying a 5-pound payload, setting another unofficial flight endurance record ...
Glimpsing a greener future: Computer model foresees effects of alternative transportation fuels
Nov 16, 2009 |
2.5 / 5 (4) |
1
(PhysOrg.com) -- It's the year 2060, and 75 percent of drivers in the Greater Los Angeles area have hydrogen fuel cell vehicles that emit only water vapor.
More than 1,000 patients in US admitted annually for aviation-related injuries
Dec 01, 2009 |
4 / 5 (1) |
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The first ever published study of aviation-related injuries and deaths in the U.S. finds that more than 1,013 patients are admitted to U.S. hospitals with aviation-related injuries annually, and that 753 aviation-deaths occur ...
Research reveals exactly how coughing is triggered by environmental irritants
Nov 23, 2009 |
4 / 5 (1) |
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(PhysOrg.com) -- Scientists have revealed how environmental irritants such as air pollution and cigarette smoke cause people to cough, in research published today in the American Journal of Respiratory an ...
Braking news: Particles from car brakes harm lung cells
Nov 20, 2009 |
5 / 5 (2) |
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Real-life particles released by car brake pads can harm lung cells in vitro. Researchers writing in BioMed Central's open access journal Particle and Fibre Toxicology found that heavy braking, as in an emergency stop, caused ...
Hidden threat: Elevated pollution levels near regional airports
Nov 18, 2009 |
not rated yet |
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Scientists are reporting evidence that air pollution — a well-recognized problem at major airports — may pose an important but largely overlooked health concern for people living near smaller regional airports. ...
Path to good health, less pollution is the sidewalk: report
Nov 09, 2009 |
4 / 5 (1) |
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US pressure groups joined forces Monday to urge authorities to spend more to improve Americans' health and cut greenhouse gas emissions.
Rocket launches Air Force satellite from Fla.
Space & Earth / Space Exploration
9 hours ago |
not rated yet |
1
(AP) -- A rocket carrying an Air Force satellite that will be used by the military has launched from Cape Canaveral.
Ohio school district sues over air pollution
Nov 28, 2009 |
5 / 5 (1) |
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(AP) -- A school district near Cincinnati is suing a plastics plant, accusing it of continuing to release chemicals in the air that exceed government safety standards.
New climate targets may not change daily life much
Nov 27, 2009 |
3.5 / 5 (19) |
31
(AP) -- Americans' day-to-day lives won't change noticeably if President Barack Obama achieves his newly announced goal of slashing carbon dioxide pollution by one-sixth in the next decade, experts say.
Invading camels to be shot in Australian town
Nov 26, 2009 |
5 / 5 (1) |
0
(AP) -- Australian authorities plan to corral about 6,000 wild camels with helicopters and gun them down after they overran a small Outback town in search of water, trampling fences, smashing tanks and contaminating ...
Barn personnel experience higher-than-average rates of respiratory symptoms
Nov 20, 2009 |
not rated yet |
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The estimated 4.6 million Americans involved in the equine industry may be at risk of developing respiratory symptoms due to poor air quality in horse barns, according to a questionnaire study undertaken earlier this year ...
Green heating and cooling technology turns carbon from eco-villain to hero
Nov 10, 2009 |
3.7 / 5 (3) |
1
Carbon is usually typecast as a villain in terms of the environment but researchers at the University of Warwick have devised a novel way to miniaturise a technology that will make carbon a key material in ...
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