Watch Comet ISON hurtle toward the sun   Comet ISON  Comet ISON
poses for a telescopic photo by the Marshall Space Flight
Center.  (Credit: NASA/MSFC/MEO/Cameron McCarty)  Comet ISON is
already a celebrity in the cosmos. The huge chunk of rock and
primordial ice is on course to make a journey around the sun,
and it's lighting up the heavens along the way. NASA released a
short movie showing the comet's trajectory over the course of
five days as it aims for the blazing beast that keeps us all
warm down here on Earth.  The movie shows Mercury and Earth for
perspective. The sun is off screen to the right. The movie was
captured by the Stereo-A spacecraft's Heliospheric Imager.  As
you watch the video, a second, smaller moving object comes into
view. That speck is Comet Encke. Encke orbits the sun every few
years. It really highlights the size of Comet ISON in
comparison.  The comet's fate is still undecided, but it will
spend Thanksgiving even closer to the sun as it closes in on its
intended U-turn around the s