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
Research shows some plants can remove indoor pollutants
17 hours ago |
4.7 / 5 (12) |
1
(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 ...
More than 1,000 patients in US admitted annually for aviation-related injuries
Dec 01, 2009 |
4 / 5 (1) |
0
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 ...
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 ...
Search results for air
Tactile input affects what we hear: study
Medicine & Health / Psychology & Psychiatry
Nov 30, 2009 |
not rated yet |
0
Humans use their whole bodies, not just their ears, to understand speech, according to University of British Columbia linguistics research.
New algorithms for computerized, large-scale surveillance
Dec 02, 2009 |
3 / 5 (1) |
0
A recent AFOSR-funded technology should enable the Air Force to achieve advances in object and target detection technology by using sophisticated algebraic theories called groups, rings and fields.
When roots lose contact
Nov 30, 2009 |
5 / 5 (1) |
0
Plant roots can shrink as a result of water deficit and lose contact with the surrounding soil. This effect has been suspected for a long time, but has only now been demonstrated for a fact with the help of ...
NRL Sensor Observes First Light
Space & Earth / Space Exploration
18 hours ago |
not rated yet |
0
The Special Sensor Ultraviolet Limb Imager (SSULI) developed by NRL's Spacecraft Engineering Department and Space Science Division, launched October 18, 2009 on the U.S. Air Force Defense Meteorological Satellite ...
Air Force Center of Excellence awarded in nanostructures and improved cognition
Nanotechnology / Nanomaterials
Dec 01, 2009 |
not rated yet |
0
The Georgia Institute of Technology has been awarded a U.S. Air Force Center of Excellence to design nanostructures for energy harvesting and adaptive materials, and to develop tools to optimize critical cognitive ...
CPR is successful without mouth-to-mouth, but not without oxygen
Nov 30, 2009 |
3 / 5 (1) |
0
People can survive cardiac arrest if they receive only chest compressions during attempts to revive them - as advised by the current American Heart Association guidelines. But they cannot survive without access to oxygen ...
TacSat-4 spacecraft complete and awaiting launch
Space & Earth / Space Exploration
Dec 01, 2009 |
1 / 5 (1) |
1
Naval Research Laboratory (NRL) engineers have completed all environmental and performance testing on the TacSat-4 COMMx payload. This completes the entire TacSat-4 spacecraft as the spacecraft bus was completed ...
Santa's Sleigh: Researcher Explains Science Behind St. Nick's Christmas Magic
18 hours ago |
5 / 5 (7) |
5
(PhysOrg.com) -- Santa skeptics have long considered St. Nick’s ability to deliver toys to the world’s good girls and boys in the course of one night a scientific impossibility. But new research shows that ...
Naked mole rats may hold clues to surviving stroke
Nov 30, 2009 |
not rated yet |
0
Blind, nearly hairless, and looking something like toothy, plump, pink fingers, naked mole rats may rank among nature's most maligned creatures, but their unusual physiology endears them to scientists.
Nida getting knocked by winds, and 97W piquing interest
Space & Earth / Earth Sciences
17 hours ago |
not rated yet |
0
Nida is now a tropical storm, and is being knocked around by wind shear in the Western Pacific. Satellite imagery has confirmed Nida's center of circulation is exposed and the storm is losing its circular ...
List of search results for air
