Solar System Discoveries

Who discovered the planets? For many of the planets in the solar system, we'll never know! Some planets are so bright in the sky that the first observers of these planets are lost in the distant past of early civilizations. Venus was carefully observed in early Mesoamerican cultures. The most distant planets were discovered in the last century, and we're now still discovering Dwarf planets, in our solar system and beyond. Visit the links here to find out more about what we know about the discovery of planets."
Have you ever seen the <a href="/earth/Magnetosphere/aurora.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Southern or Northern Lights</a>? Earth isn't the only planet that puts on these beautiful light shows, which are also called the "<a href="/earth/Magnetosphere/aurora.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">aurora</a>". Aurora have been seen at both <a href="/saturn/saturn_polar_regions.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">poles of Saturn</a>, too, as well as at the poles of <a href="/jupiter/magnetosphere/jupiter_aurora.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Jupiter</a>.  These "<a href="/earth/Magnetosphere/tour/tour_earth_magnetosphere_09.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">curtains of light</a>" sometimes rise 1,200 miles (2,000 km) above the <a href="/saturn/atmosphere/S_clouds_overview.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">cloud tops</a> near Saturn's poles. The <a href="/space_missions/HST.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Hubble Space Telescope</a> took this picture in 2004.<p><small><em>Image courtesy of NASA, ESA, J. Clarke (Boston University), and Z. Levay (STScI)</em></small></p>Neptune's <a href="/neptune/lower_atmosphere.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">atmosphere</a> shows
a striped pattern of
<a href="/neptune/atmosphere/N_clouds_overview.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">clouds</a>.
This cloud pattern is very similar to that of
<a href="/jupiter/jupiter.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Jupiter</a> and
<a href="/saturn/saturn.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Saturn</a>.
Neptune even has a <a href="/neptune/atmosphere/N_clouds_GDS.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Great Dark
Spot</a> similar
to Jupiter's <a href="/jupiter/atmosphere/J_clouds_GRS.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Great
Red Spot</a>.
The Great Dark Spot of Neptune is thought to be a hole, similar to the hole
in the <a href="/earth/Atmosphere/ozone_layer.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">ozone layer on
Earth</a>,
in the <a href="/physical_science/chemistry/methane.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">methane</a> cloud
deck of Neptune.<p><small><em>Image courtesy of NASA</em></small></p><a href="/mercury/mercury.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Mercury</a>, the innermost planet of the solar system, is a little bigger than the Earth's Moon. The <a href="/mercury/Interior_Surface/Surface/surface_overview.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">surface</a> of the planet is covered with craters, like the Moon, but temperatures there can reach over 800&deg;F because Mercury is so close to the Sun and rotates so slowly.  This picture was taken by the <a href="/space_missions/robotic/messenger/messenger.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">MESSENGER spacecraft</a> in October 2008.<p><small><em>Image courtesy of NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.</em></small></p>The uniquely red <a href="/mars/interior/Martian_global_geology.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">global surface</a> of Mars is marked by many interesting features - some like those on the <a href="/earth/earth.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">Earth</a> and others strangely different. The reddish color is caused by rust (iron oxide) in the <a href="/mars/exploring/martian_soils.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">soil</a>.  Some of these features are; <a href="/mars/interior/mars_volcanoes.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">volcanoes</a>, canyon systems, <a href="/mars/interior/Martian_running_water.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">river beds</a>, <a href="/mars/interior/Mars_cratered_terrain.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">cratered terrain</a>, and <a href="/mars/interior/Martian_dunefields.html&dev=1/earth/Atmosphere/moons/=/earth/climate/cli_greengas.html">dune fields</a>.  This image shows a global mosaic of 102 Viking 1 Orbiter images of Mars taken in February, 1980.<p><small><em>Image courtesy of NASA.</em></small></p>

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