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=elem">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>This dramatic view of Jupiter's <a href="/jupiter/atmosphere/J_clouds_GRS.html&edu=elem">Great Red Spot</a> and its surroundings was obtained by <a href="/space_missions/voyager.html&edu=elem">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>How did life evolve on <a href="/earth/earth.html&edu=elem">Earth</a> during the <a href="/earth/past/Archean.html&edu=elem">Archean</a>, when the <a href="/sun/sun.html&edu=elem">Sun</a> was about 25% weaker than today?  The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html&edu=elem">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html&edu=elem">greenhouse</a> gas concentration was the same as today.  <a href="http://www.manchester.ac.uk/aboutus/news/display/?id=10798">Researchers</a> studying the <a href="/physical_science/physics/atom_particle/isotope.html&edu=elem">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html&edu=elem">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html&edu=elem">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html&edu=elem">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=elem">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p>This image is a montage of high resolutions photographs of the Earth taken in January 2012 by the Visible/Infrared Imager Radiometer Suite (VIIRS) instrument on the Suomi NPP satellite.  The image shows many stunning details of <a href="http://www.windows2universe.org/earth/earth.html">our home planet</a> - <a href="http://solarsystem.nasa.gov/multimedia/gallery/VIIRS_4Jan2012.jpg">particularly at high resolution</a>. The beauty of our planet is obvious from space - our blue <a href="http://www.windows2universe.org/earth/Water/overview.html">waters</a>, our white <a href="http://www.windows2universe.org/earth/Atmosphere/cloud.html">clouds</a>, and the green from <a href="http://www.windows2universe.org/earth/Life/life.html">life</a> abundant at the surface.<p><small><em>Image courtesy of NASA</em></small></p>As temperatures rise and soil moisture decreases, plants are stressed, which can lead to <a href="/earth/climate/crops_withering.html&edu=elem">crop withering</a>. <a href="/teacher_resources/online_courses/health/events_health.html&edu=elem">Droughts</a> accompanied by increased temperatures can lead to famine, social and political disruptions. Scientists are  helping with early identification of drought that might trigger food shortages. Watch the NBC Learn video - <a href="/earth/changing_planet/withering_crops_intro.html&edu=elem">Changing Planet: Withering Crops</a> to find out more.<p><small><em>Image taken by Tomas Castelazo, Creative Commons <a href=&quot;http://creativecommons.org/licenses/by/3.0/deed.en&quot;>Attribution 3.0 Unported</a> license.</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">solar system</a>. The space probe is about 19 billion km from the <a href="/sun/sun.html&edu=elem">Sun</a>.  <a href="/space_missions/voyager.html&edu=elem">Voyager 1 and 2</a> were launched in 1977 on a <a href="/space_missions/voyager.html&edu=elem">mission</a> that flew them both by <a href="/jupiter/jupiter.html&edu=elem">Jupiter</a> and <a href="/saturn/saturn.html&edu=elem">Saturn</a>, with Voyager 2 continuing to <a href="/uranus/uranus.html&edu=elem">Uranus</a> and <a href="/neptune/neptune.html&edu=elem">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">Sun</a>.<p><small><em>Image courtesy of NASA</em></small></p>

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