Couldn't find element LayerAd

Error finding content

Windows to the Universe

Shop Windows to the Universe

Our Glaciers: Then and Now activity kit helps you see the changes taking place in glaciers around the world. See all our activity kits and classroom activities.
Sinkholes are <a href="/php/tour_test_sqli.php?page=/teacher_resources/main/frameworks/esl_bi8.html&edu=high">natural hazards</a> in many places around the world. They are formed when water dissolves underlying <a href="/php/tour_test_sqli.php?page=/earth/Water/carbonates.html&edu=high">limestone</a>, leading to collapse of the surface.  Hydrologic conditions such as a lack of rainfall, lowered water levels, or excessive rainfall can all contribute to sinkhole development. On 2/28/2013, a sinkhole suddenly developed under the house outside of Tampa, Florida, leading to the tragic death of its occupant, Jeff Bush.<p><small><em>Image courtesy of Southwest Florida Water Management District</em></small></p>A group of
  Emperor penguins wait their turn to dive into the ocean near <a
  href="/php/tour_test_sqli.php?page=/people/postcards/jean_pennycook_11_29_0.html&edu=high">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="/php/tour_test_sqli.php?page=/earth/extreme_environments.html&edu=high">extreme
  environment</a>.<p><small><em> Image courtesy of Emily Stone,   National Science Foundation</em></small></p>This dramatic view of Jupiter's <a href="/php/tour_test_sqli.php?page=/jupiter/atmosphere/J_clouds_GRS.html&edu=high">Great Red Spot</a> and its surroundings was obtained by <a href="/php/tour_test_sqli.php?page=/space_missions/voyager.html&edu=high">Voyager 1</a> on Feb. 25, 1979, when the spacecraft was 5.7 million miles (9.2 million kilometers) from Jupiter. Cloud details as small as 100 miles (160 kilometers) across can be seen here. The colorful, wavy cloud pattern to the left of the Red Spot is a region of extraordinarily complex end variable wave motion.<p><small><em>Image courtesy of NASA</em></small></p>This historic image is the first ever taken from a spacecraft in orbit about <a href="/php/tour_test_sqli.php?page=/mercury/mercury.html&edu=high">Mercury</a>, the innermost planet of the solar system.  Taken on 3/29/2011 by <a href="/php/tour_test_sqli.php?page=/space_missions/robotic/messenger/messenger.html&edu=high">MESSENGER</a>, it shows numerous craters across the <a href="/php/tour_test_sqli.php?page=/mercury/Interior_Surface/Surface/surface_overview.html&edu=high">surface</a> of the planet.  Temperatures there can reach over 800°F because Mercury is so close to the Sun and rotates so slowly.  MESSENGER entered orbit around Mercury earlier in March 2011.<p><small><em>NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington</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="/php/tour_test_sqli.php?page=/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>The spinning vortex of <a href="https://www.windows2universe.org/saturn/saturn.html">Saturn</a>'s north polar storm resembles a giant deep red rose surrounded by green foliage in this false-color <a href="http://www.nasa.gov/mission_pages/cassini/multimedia/pia14944.html">image</a> from NASA's <a href="https://www.windows2universe.org/missions/cassini.html">Cassini spacecraft</a>. The eye is 2,000 kilometers across with cloud speeds as fast as 150 meters per second.
It is not known how long this newly discovered north-polar <a href="https://www.windows2universe.org/earth/Atmosphere/hurricane/hurricane.html">hurricane</a> has been active.
The view was acquired at a distance of approximately 419,000 kilometers from Saturn.<p><small><em>NASA/JPL-Caltech/SSI</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