Scientists at the University of Michigan have found that <a href="/earth/polar/cryosphere_permafrost1.html&edu=high">permafrost</a> in the <a href="/earth/polar/polar_north.html&edu=high">Arctic</a> is extremely sensitive to sunlight. Exposure to sunlight releases carbon gases trapped in the permafrost, including <a href="/earth/climate/earth_greenhouse.html&edu=high">climate-warming</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high">carbon dioxide</a>, to the <a href="/earth/Atmosphere/overview.html&edu=high">atmosphere</a> much faster than previously thought.<p><small><em>George Kling, The University of Michigan</em></small></p>An artist's rendering of the moment of impact of a massive <a href="/our_solar_system/meteors/meteors.html&edu=high">meteorite</a> at the end of the Cretaceous (at the end of the <a href="/earth/geology/hist_mesozoic.html&edu=high">Mesozoic Era</a>). Many scientists have concluded for decades that a meteorite four to six kilometers in diameter impacted the Earth at this time, resulting in a <a href="/earth/past/KTextinction.html&edu=high">mass extinction of dinosaurs</a> and many other life forms. Recent research suggests that perhaps <a href="/headline_universe/olpa/chicxulub.html&edu=high">massive volcanic eruptions</a> may be been responsible for the extinction.<p><small><em>Courtesy of Don Davis, NASA</em></small></p>Lunar eclipses are special events that only occur when certain conditions are met. First of all, the Moon must be in <a href="/the_universe/uts/moon3.html&edu=high">full phase</a>. Secondly, the <a href="/sun/sun.html&edu=high">Sun</a>, <a href="/earth/earth.html&edu=high">Earth</a> and <a href="/earth/moons_and_rings.html&edu=high">Moon</a> must be in a perfectly straight line. If both of these are met, then the Earth's shadow can block the Sun's light from hitting the Moon. The reddish glow of the Moon is caused by light from the Earth's limb scattering toward the Moon, which is reflected back to us from the Moon's surface.<p><small><em>Image credit - Doug Murray, Palm Beach Gardens, Florida</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>According to a Greek legend, the sea god Poseidon placed the figure of <a href="/the_universe/Constellations/circumpolar/cassiopeia.html&edu=high">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>Stars don't last forever. Occasionally, a star bigger than our Sun will end its life in a huge explosion, called a <a href="/the_universe/supernova.html&edu=high">supernova</a>. The center of the star collapses in less than a second, blowing away the outer layers of the star. There are many beautiful images of supernova remnants, the expanding shell of gas made up of the outer layers of the original star. This image is the Vela Supernova Remnant.<p><small><em>Image courtesy of the Anglo-Australian Observatory/Royal Observatory Edinburgh</em></small></p>


Attention Educator Member Teachers! Go to our special offers page for information about attractive upcoming professional development events next year. Not an Educator Member? Join Today!
Check out resources from our Affiliates!

Global locations of visitors using this page right now

Welcome to Windows to the Universe - your portal to discovery! Explore the wealth of information available here to learn about the Earth and Space sciences and related topics in the humanities including mythology, art, poetry, and more.

Our mobile website version is available now on your phone's web browser and give us feedback.

NEW Subscription Opportunities for Educators and their Students! - Classroom, School, and District Subscription Options.

Windows to the Universe Professional Development - On-site, in your school - find out more about this opportunity here. Information about our upcoming workshops and events is available on our Teacher Resources/Workshops page.

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
Brought to you by NSF

Video: Beaufort Scale of Wind Speeds

Did you know that our system of wind speed measurement has roots in seafaring history? Understanding wind speed was critical for sailors. Check out this video from the Little Shop of Physics ...Read more
Brought to you by CMMAP

Modeling Space Weather

Computer models help scientists study all aspects of space weather. Models help us understand activity on the Sun, the flow of the solar wind in space, and planetary magnetospheres ...Read more
Brought to you by CISM

The Earth's Magnetic Field

The magnetic field of the Earth is surrounded in a region called the magnetosphere. The magnetosphere prevents most of the particles from the sun, carried in solar wind, from hitting the Earth ...Read more

Mercury

Mercury is the smallest planet in our Solar System. It is also the closest planet to the Sun, so it is very, very hot. A "year" on Mercury lasts just 88 days ...Read more

Historical Events

Full Earth and Space Science    History Calendar (Members only)

Teacher Opportunities

Full Teacher Events Calendar (Educator Members only)

Buried Treasure!

The Skywatchers of the Americas

Bernabe Cobo said in 1653 that there are, "no people, no matter how barbaric and primitive, that do not...Read more


Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA