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.

2009 July 28
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A Floral Aurora Corona
Credit & Copyright: Zoltan Kenwell (Infocus Imagery)

Explanation: Few aurorae show this level of detail. Above, a standard digital camera captured a particularly active and colourful auroral corona that occurred last week above Alberta, Canada. With a shape reminiscent of a flower, the spectacular aurora had an unusually high degree of detail. The vivid green and purple auroral colours are caused by high atmospheric oxygen and hydrogen reacting to a burst of incoming electrons. Many photogenic aurorae have been triggered from a solar wind stream that recently passed the Earth. The aurorae were unexpected because the initiating Sun has been unusually quiet of late.


Note: An APOD editor will review great space images this Saturday night at Ft. Wilkins, Michigan.
Tomorrow's picture: devils way


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