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Solar System Exploration
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Sungrazing Comets
Sungrazing Comets
Close Encounters of the Solar Kind
Their title says it all: sungrazing comets orbit deeper into the sun's outer atmosphere (the corona) than the average comet - so deep that they appear to skim the surface of the sun.
Let's see what happens to sungrazing comets.
To be considered a sungrazer, a comet must come within three solar radii (Rsun) of the sun at closest approach (perihelion). One Rsun is equal to about 432 thousand miles (about 700 thousand km).
All comets are transformed by the sun's energy and heat; changing from an icy piece of orbiting space debris into a bright and beautiful object with not one, but two tails.
  • Visibility Increases (usually)
  • Ice and Rocks Sublimate (partially or completely - just like dry ice)
  • It May Break Up (partially or completely)
    Most sungrazing comets are small and do not make it completely around the sun, but instead disintegrate or vaporize - never to be seen again.
    A few sungrazers have been known to survive their trip around the sun. Those that do must be large and sturdy enough to endure the journey.
    If the geometry is right, a large sungrazer survivor can be quite spectacular when viewed from the Earth.
    SOHO Mission Graphic
    Did you know that just about every day the Solar and Heliospheric Observatory (SOHO) sees a sungrazing comet disappear in the solar atmosphere?
    Comet Diagram Background
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    Last Updated: 15 Nov 2013