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Our Solar System

Our solar system is filled with a wide assortment of celestial bodies - the Sun itself, our eight planets, dwarf planets, and asteroids - and on Earth, life itself! The inner solar system is occasionally visited by comets that loop in from the outer reaches of the solar system on highly elliptical orbits. In the outer reaches of the solar system, we find the Kuiper Belt and the Oort cloud. Still farther out, we eventually reach the limits of the heliosphere, where the outer reaches of the solar system interact with interstellar space. Solar system formation began billions of years ago, when gases and dust began to come together to form the Sun, planets, and other bodies of the solar system.

This dramatic view of Jupiter's <a href="/jupiter/atmosphere/J_clouds_GRS.html">Great Red Spot</a> and its surroundings was obtained by <a href="/space_missions/voyager.html">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>Have you ever seen the <a href="/earth/Magnetosphere/aurora.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">aurora</a>". Aurora have been seen at both <a href="/saturn/saturn_polar_regions.html">poles of Saturn</a>, too, as well as at the poles of <a href="/jupiter/magnetosphere/jupiter_aurora.html">Jupiter</a>.  These "<a href="/earth/Magnetosphere/tour/tour_earth_magnetosphere_09.html">curtains of light</a>" sometimes rise 1,200 miles (2,000 km) above the <a href="/saturn/atmosphere/S_clouds_overview.html">cloud tops</a> near Saturn's poles. The <a href="/space_missions/HST.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>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">full phase</a>. Secondly, the <a href="/sun/sun.html">Sun</a>, <a href="/earth/earth.html">Earth</a> and <a href="/earth/moons_and_rings.html">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>According to <a href="">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">solar system</a>. The space probe is about 19 billion km from the <a href="/sun/sun.html">Sun</a>.  <a href="/space_missions/voyager.html">Voyager 1 and 2</a> were launched in 1977 on a <a href="/space_missions/voyager.html">mission</a> that flew them both by <a href="/jupiter/jupiter.html">Jupiter</a> and <a href="/saturn/saturn.html">Saturn</a>, with Voyager 2 continuing to <a href="/uranus/uranus.html">Uranus</a> and <a href="/neptune/neptune.html">Neptune</a>. Voyager 2 is the longest continuously operated spacecraft. It is about 15 billion km away from the <a href="/sun/sun.html">Sun</a>.<p><small><em>Image courtesy of NASA</em></small></p>Comets are <a href="/comets/comet_nucleus.html">lumps</a> of ice
and dust that periodically come into the center of the solar system from
its <a href="/comets/Oort_cloud.html">outer
Some comets make <a href="/comets/perihelion_pass.html">repeated
trips</a> to the inner
solar system. When comets get close enough to the Sun, heat
makes them start to <a href="/comets/sublimation.html">evaporate</a>.
Jets of gas and dust form long
<a href="/comets/tail.html">tails</a> that we can see from
This photograph shows <a href="/comets/comets_table.html">Comet
which visited the inner solar system in 1973.  It has an
<a href="/physical_science/physics/mechanics/orbit/orbit_shape_interactive.html">orbit</a> of
about 75,000 years!<p><small><em>Image courtesy of NASA</em></small></p>The spinning vortex of <a href="">Saturn</a>'s north polar storm resembles a giant deep red rose surrounded by green foliage in this false-color <a href="">image</a> from NASA's <a href="">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="">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>

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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