Spirals On Earth and in the Heavens

March 14, 2011

M51-isabel_lula 
Photographer: Brian Lula; Brian's Website
Summary Authors: Brian Lula; Jim Foster

The image pair above features an astrophoto of a spiral galaxy in the constellation of Canes Venatici, taken through my 20-inch (50 cm) telescope, and a GOES satellite image of Hurricane Isabel. In mid September 2003, Hurricane Isabel imperiled parts of the Mid-Atlantic region of the U.S. making landfall in North Carolina on September 18 as a category 3 hurricane. While this storm was spinning northward, I was working from my home in central Massachusetts on processing image data for M51 (the Whirlpool Galaxy), a large spiral galaxy over 30 million light years away in collision with a satellite galaxy (at lower left of M51). I couldn't help but notice the similarities in the spirals between the two systems. They're both a form of logarithmic spirals, which can also be found in plants like cauliflower and possibly in the shells of certain mollusks. Both images taken on September 18, 2003. 

Astrophoto details: Telescope - 20 in Astrograph; SBIG 6303E CCD Camera. Exposures: Clear - 2 hours; Red - 1 hour; Green - 1 hour; Blue - 1 hour.