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&dev=1the">full phase</a>. Secondly, the <a href="/sun/sun.html&edu=high&dev=1the">Sun</a>, <a href="/earth/earth.html&edu=high&dev=1the">Earth</a> and <a href="/earth/moons_and_rings.html&edu=high&dev=1the">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 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>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=high&dev=1the">solar system</a>. The space probe is about 19 billion km from the <a href="/sun/sun.html&edu=high&dev=1the">Sun</a>. <a href="/space_missions/voyager.html&edu=high&dev=1the">Voyager 1 and 2</a> were launched in 1977 on a <a href="/space_missions/voyager.html&edu=high&dev=1the">mission</a> that flew them both by <a href="/jupiter/jupiter.html&edu=high&dev=1the">Jupiter</a> and <a href="/saturn/saturn.html&edu=high&dev=1the">Saturn</a>, with Voyager 2 continuing to <a href="/uranus/uranus.html&edu=high&dev=1the">Uranus</a> and <a href="/neptune/neptune.html&edu=high&dev=1the">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=high&dev=1the">Sun</a>.<p><small><em>Image courtesy of NASA</em></small></p>As permafrost thaws, the land, atmosphere, water resources, ecosystems, and human communities are affected. Coastal areas and hillsides are vulnerable to erosion by thawing of permafrost. Thawing permafrost also causes a positive feedback to global warming, as carbon trapped within the once-frozen soils is released as <a href="/physical_science/chemistry/methane.html&edu=high&dev=1the">methane</a>, a powerful <a href="/earth/climate/cli_greengas.html&edu=high&dev=1the">greenhouse gas</a>. Watch the NBC Learn video - <a href="/earth/changing_planet/permafrost_methane_intro.html&edu=high&dev=1the">Thawing Permafrost and Methane</a> to find out more.<p><small><em>Image courtesy of the USGS</em></small></p>New observations by the MESSENGER spacecraft provide support for the hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed (shown in red) polar craters. Areas where polar deposits of ice imaged by Earth-based radar are shown in yellow.<p><small><em>Image courtesy of NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington/National Astronomy and Ionosphere Center, Arecibo Observatory</em></small></p>How did life evolve on <a href="/earth/earth.html&edu=high&dev=1the">Earth</a> during the <a href="/earth/past/Archean.html&edu=high&dev=1the">Archean</a>, when the <a href="/sun/sun.html&edu=high&dev=1the">Sun</a> was about 25% weaker than today? The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html&edu=high&dev=1the">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html&edu=high&dev=1the">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=high&dev=1the">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html&edu=high&dev=1the">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html&edu=high&dev=1the">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html&edu=high&dev=1the">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high&dev=1the">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p>


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