Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2011 October 20
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Tails of Comet Garradd
Image Credit & Copyright: Gregg Ruppel

Explanation: A good target for binoculars and small telescopes, Comet Garradd (C/2009 P1) now shines in planet Earth's evening skies, a steady performer but just below naked-eye visibility. Telescopic images like this composite from October 15 can find the comet with a lovely green coma, sporting multiple tails, and lingering against a background of faint stars. The field of view spans over 1 degree or about 2 full moons within the southern boundaries of the constellation Hercules. Now around 16 light minutes (2 astronomical units) away, P1 Garradd is an intrinsically large comet, but will never make a very close approach to Earth or the Sun while sweeping through the inner solar system. As a result, the comet will likely stay a sight for telescopic eyes only, moving slowly through the sky and remaining in Hercules during the coming months.

Tomorrow's picture: Clouds of Perseus

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