Atmosphere

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An atmosphere (from Greek ατμός - atmos, 'vapor' + σφαίρα - sphaira, 'sphere') is a layer of gases that may surround a material body of sufficient mass, by the gravity of the body, and are retained for a longer duration if gravity is high and the atmosphere's temperature is low. Some planets consist mainly of various gases, but only their outer layer is their atmosphere (see gas giants).

The term stellar atmosphere describes the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Relatively low-temperature stars may form compound molecules in their outer atmosphere. Earth's atmosphere, which contains oxygen used by most organisms for respiration and carbon dioxide used by plants, algae and cyanobacteria for photosynthesis, also protects living organisms from genetic damage by solar ultraviolet radiation. Its current composition is the product of billions of years of biochemical modification of the paleoatmosphere by living organisms.

For more information about 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 atmosphere

CO2 levels rising in troposphere over rural areas

Space & Earth / Earth Sciences

Dec 03, 2009 | 2.7 / 5 (3) | 4

Spanish researchers have measured CO2 levels for the past three years in the troposphere (lower atmosphere) over a sparsely inhabited rural area near Valladolid. The results, which are the first of their kind ...

Search results for atmosphere

Cosmic rays hunted down: Physicists are closing in on the origin of cosmic rays

Space & Earth / Astronomy

10 hours ago | 4 / 5 (5) | 3

(PhysOrg.com) -- A thin rain of charged particles continually bombards our atmosphere from outer space. The mysterious particles were first detected 100 years ago but until 10 years ago when a new type of ...

Snowflake chemistry could give clues about ozone depletion

Chemistry / Analytical Chemistry

14 hours ago | 5 / 5 (1) | 0

There is more to the snowflake than its ability to delight schoolchildren and snarl traffic.

Virgin Galactic unveils commercial spaceship

Space & Earth / Space Exploration

17 hours ago | 4.6 / 5 (8) | 1

(AP) -- A spacecraft designed to rocket wealthy tourists into space as early as 2011 was unveiled Monday in what backers of the venture hope will signal a new era in aviation history.

White, but not pure

Space & Earth / Environment

17 hours ago | 4.5 / 5 (2) | 1

Even the snow on Aconcagua Mountain in the Andes is polluted with PCBs. An international team of researchers detected low concentrations of these toxic, carcinogenic chlorine compounds in samples taken from ...

Space technology optimises windmill efficiency

Technology / Engineering

18 hours ago | 3 / 5 (2) | 0

(PhysOrg.com) -- A French start-up company from ESA's Business Incubation Centre in the Netherlands has developed a small instrument to measure wind speed and direction from the ground up to heights of 200 ...

Researchers show brain waves can 'write' on a computer in early tests

Medicine & Health / Research

Dec 07, 2009 | 4.9 / 5 (17) | 4

Neuroscientists at the Mayo Clinic campus in Jacksonville, Fla., have demonstrated how brain waves can be used to type alphanumerical characters on a computer screen. By merely focusing on the "q" in a matrix of letters, ...

Keeping Mars Contained

Space & Earth / Space Exploration

Dec 04, 2009 | 5 / 5 (3) | 1

When robotic spacecraft bring a sample of Mars back to Earth, scientists will need specially-designed facilities to study the samples and prevent them from escaping to the outside world.

Steering the Ares Rockets on a Straight Path

Space & Earth / Space Exploration

Dec 04, 2009 | 5 / 5 (1) | 1

(PhysOrg.com) -- The Ares I-X rocket stood more than 325 feet tall on the launch pad at NASA's Kennedy Space Center, Fla. Spectators watched in awe as its massive solid rocket motor blazed to life with a thunderous ...

Safe journey for works of art

Technology / Engineering

Dec 04, 2009 | 4 / 5 (1) | 0

Valuable paintings travel long distances when they are shipped from one place to another. To minimize damage, they are packed in special picture cases. In future, these will be equipped with sensors to detect ...