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>According to a Greek legend, the sea god Poseidon placed the figure of <a href="/the_universe/Constellations/circumpolar/cassiopeia.html&dev=1/earth/Atmosphere/moons/water_watersheds.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>A new study has found that <a href="/earth/Atmosphere/airpollution_intro.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">pollution</a> from <a href="/earth/Atmosphere/particulates.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">fine particles</a> in the air - mainly the result of burning coal or <a href="/earth/interior/eruptions.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">volcanic eruptions</a> - can shade <a href="/earth/Life/cnidarian.html&dev=1/earth/Atmosphere/moons/water_watersheds.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>A group of Emperor penguins wait their turn to dive into the ocean near <a href="/people/postcards/jean_pennycook_11_29_0.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">Ross Island, Antarctica</a> on November 3, 2004. Emperor penguins routinely dive to 500 meters in search of food. Scientists are interested in understanding how they can endure the stress of these dives in such an <a href="/earth/extreme_environments.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">extreme environment</a>.<p><small><em> Image courtesy of Emily Stone, National Science Foundation</em></small></p>The <a href="http://www.windows2universe.org/earth/Atmosphere/tornado/fujita.html">EF-5</a> <a href="http://www.windows2universe.org/earth/Atmosphere/tornado.html">tornado</a> that hit El Reno, Oklahoma on May 31st, 2013 was the widest ever recorded in the US, according to the National Weather Service in Norman Oklahoma. The tornado, which remained on the ground for 40 minutes and reached 2.6 miles across (4.2 km), took the lives of 18 people including storm chasers Tim Samaras, Paul Samaras and Carl Young.<p><small><em>Image courtesy of National Weather Service, Norman Oklahoma</em></small></p>There are over 900 <a href="/the_universe/uts/megalith.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">rings of stone</a> located in the British Isles. The most famous of these stone rings is of course, <a href="/the_universe/uts/stonehenge.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">Stonehenge</a>. The stones of Stonehenge were put in place between 3,000 B.C and 2,000 B.C. by neolithic people.Some speculate that the site was built as a temple of worship of the ancient Earth deities. Some say it was used as an <a href="/the_universe/uts/stonehenge_astro.html&dev=1/earth/Atmosphere/moons/water_watersheds.html">astronomical observatory</a> of sorts. Still others say it was a burial ground.<p><small><em> Image courtesy of Corel Photography.</em></small></p>


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The Rings of Jupiter

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