A new study has found that <a href="/earth/Atmosphere/airpollution_intro.html&edu=elem&dev=1/k=/sed_intro.html">pollution</a> from <a href="/earth/Atmosphere/particulates.html&edu=elem&dev=1/k=/sed_intro.html">fine particles</a> in the air - mainly the result of burning coal or <a href="/earth/interior/eruptions.html&edu=elem&dev=1/k=/sed_intro.html">volcanic eruptions</a> - can shade <a href="/earth/Life/cnidarian.html&edu=elem&dev=1/k=/sed_intro.html">corals</a> from sunlight and cool the surrounding water resulting in reduced growth rates. Coral growth rates in the Caribbean were affected by volcanic aerosol emissions in the early 20th century and by aerosol emissions caused by humans in the later 20th century. For more information, see the <a href="http://www.exeter.ac.uk/news/featurednews/title_278202_en.html">press release</a>.<p><small><em>Image courtesy of Toby Hudson (Wikimedia Commons)</em></small></p><p>Something on Earth is always burning! NASA's Earth Observatory tracks wildfires across the world with <a href="http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MOD14A1_M_FIRE" target="_blank">maps available for viewing</a> from 2000-present. Some wildfires can restore <a href="/earth/ecosystems.html&edu=elem&dev=1/k=/sed_intro.html">ecosystems</a> to good health, but many can threaten human populations, posing a natural disaster threat.</p> <p>Check out the materials about natural disasters in <a href="/earth/natural_hazards/when_nature_strikes.html&edu=elem&dev=1/k=/sed_intro.html">NBC Learn Videos</a>, and their earth system science connections built up by the related secondary classroom activities.</p><p><small><em>NBC Learn</em></small></p>According to a Greek legend, the sea god Poseidon placed the figure of <a href="/the_universe/Constellations/circumpolar/cassiopeia.html&edu=elem&dev=1/k=/sed_intro.html">Cassiopeia</a> among the stars. It is said that Cassiopeia has a ridiculous upside-down position to punish her for having been pretentious.<p><small><em>Image courtesy of 1995 Visual Language (c). All rights reserved.</em></small></p>As permafrost thaws, the land, atmosphere, water resources, ecosystems, and human communities are affected. Coastal areas and hillsides are vulnerable to erosion by thawing of permafrost. Thawing permafrost also causes a positive feedback to global warming, as carbon trapped within the once-frozen soils is released as <a href="/physical_science/chemistry/methane.html&edu=elem&dev=1/k=/sed_intro.html">methane</a>, a powerful <a href="/earth/climate/cli_greengas.html&edu=elem&dev=1/k=/sed_intro.html">greenhouse gas</a>. Watch the NBC Learn video - <a href="/earth/changing_planet/permafrost_methane_intro.html&edu=elem&dev=1/k=/sed_intro.html">Thawing Permafrost and Methane</a> to find out more.<p><small><em>Image courtesy of the USGS</em></small></p>According to <a href="http://www.jpl.nasa.gov/news/news.php?release=2013-277">NASA scientists</a>, the Voyager 1 spacecraft entered interstellar space in August 2012, becoming the first spacecraft to leave the <a href="/our_solar_system/solar_system.html&edu=elem&dev=1/k=/sed_intro.html">solar system</a>. The space probe is about 19 billion km from the <a href="/sun/sun.html&edu=elem&dev=1/k=/sed_intro.html">Sun</a>. <a href="/space_missions/voyager.html&edu=elem&dev=1/k=/sed_intro.html">Voyager 1 and 2</a> were launched in 1977 on a <a href="/space_missions/voyager.html&edu=elem&dev=1/k=/sed_intro.html">mission</a> that flew them both by <a href="/jupiter/jupiter.html&edu=elem&dev=1/k=/sed_intro.html">Jupiter</a> and <a href="/saturn/saturn.html&edu=elem&dev=1/k=/sed_intro.html">Saturn</a>, with Voyager 2 continuing to <a href="/uranus/uranus.html&edu=elem&dev=1/k=/sed_intro.html">Uranus</a> and <a href="/neptune/neptune.html&edu=elem&dev=1/k=/sed_intro.html">Neptune</a>. Voyager 2 is the longest continuously operated spacecraft. It is about 15 billion km away from the <a href="/sun/sun.html&edu=elem&dev=1/k=/sed_intro.html">Sun</a>.<p><small><em>Image courtesy of NASA</em></small></p>Anti-crepuscular rays are beams of sunlight that appear to converge on a point opposite the sun. They are similar to crepuscular rays, but are seen opposite the sun in the sky. Anti-crepuscular rays are most frequently visible near sunrise or sunset. This photo of anti-crepuscular rays was taken at sunset in Boulder, Colorado. Crepuscular rays are usually much brighter than anti-crepuscular rays.<p><small><em> Image Courtesy of Carlye Calvin</em></small></p>


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Video About Ocean Dead Zones

Oceanographers are using robotic undersea "gliders" to study "dead zones" in the seas. View this video from the National Science Foundation ...Read more
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Clouds in Art

Landscape painters have been representing clouds in their art for centuries. Different artists with different styles have painted clouds differently. Check out the Clouds in Art Interactive ...Read more
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Physics of Space Weather

The science of physics plays a key role in many space weather phenomena. Charged particles, magnetic fields, forces and motion, and the electromagnetic spectrum are all part of space weather ...Read more
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Icebergs

Icebergs are large pieces of ice floating in the ocean that have broken off of ice shelves or glaciers in Earth's polar regions. They are a part of the cryosphere ...Read more

Jupiter

Jupiter is the largest planet in our Solar System. This giant ball of hydrogen and helium gas is large enough to contain more than 1,000 Earths. Dozens of moons circle the 5th planet from the Sun ...Read more

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Saturn's Strange Hexagon

Astronomers have discovered a strange shape in Saturn's atmosphere. The shape is a hexagon. The hexagon...Read more


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