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Dig into Montana Before History: 11K Years of Hunter-Gatherers in the Rockies and Plains by D. H. MacDonald, Ph.D. See our online store book collection.
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>The massive 9.0 magnitude <a href="/php/tour_test_sqli.php?page=/earth/geology/quake_1.html">earthquake</a> off of Honshu, Japan on <a href="/php/tour_test_sqli.php?page=/headline_universe/march112011earthquaketsunami.html">11 March 2011</a> generated a <a href="/php/tour_test_sqli.php?page=/earth/tsunami1.html">tsunami</a> that exceeded 10 meters on the coast near the epicenter.  This image shows model projections for the tsunami wave height in cm which are in good agreement with the observed waves. Our thoughts and prayers are with those who were lost, and their families, as we remember this event.<p><small><em><a href="http://blogs.agu.org/wildwildscience/files/2011/03/680_20110311-TsunamiWaveHeight.jpg">NOAA Tsunami Wave Height Projections image</a></em></small></p>On May 20, 2013, a massive EF5 <a href="http://www.windows2universe.org/earth/Atmosphere/tornado.html">tornado</a> hit Moore, Oklahoma, devastating communities and lives.  The tornado, on the ground for 40 minutes, took a path through a subdivision of homes, destroying block after block of homes, and hitting two elementary schools just as school was ending as well as a hospital. Hundreds of people were injured, and 24 were killed.<p><small><em>Image courtesy of Ks0stm, Creative Commons Attribution-Share Alike 3.0 Unported license</em></small></p>A new study has found that <a href="/php/tour_test_sqli.php?page=/earth/Atmosphere/airpollution_intro.html">pollution</a> from <a href="/php/tour_test_sqli.php?page=/earth/Atmosphere/particulates.html">fine particles</a> in the air - mainly the result of burning coal or <a href="/php/tour_test_sqli.php?page=/earth/interior/eruptions.html">volcanic eruptions</a> - can shade <a href="/php/tour_test_sqli.php?page=/earth/Life/cnidarian.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>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>Greenland’s <a href="http://www.windows2universe.org/earth/polar/cryosphere_glacier1.html">ice sheet</a> saw a record <a href="http://www.windows2universe.org/headline_universe/olpa/greenland_10dec07.html">melt</a> in July 2012.  Scientists studying this event have found that this melting event was triggered by an influx of unusually warm air and amplified by the presence of a blanket of thin low-level <a href="http://www.windows2universe.org/earth/Atmosphere/cloud.html">clouds</a> which pushed temperatures up above freezing.  For more information see the <a href="http://www.news.wisc.edu/21638">press release</a> from the University of Wisconsin Madison.<p><small><em>Image courtesy of University of Wisconsin-Madison</em></small></p>

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF