Saturn requires good seeing to take a sharp picture and I was fortunate to find some on the night of April 15th. Tethys was predicted to pass in front of the disk but finding it was nearly impossible. With a diameter just over 1000 kilometers and almost 1.3 billion kilometers away, imaging Tethys against the bright disk of saturn is like photographing a volleyball on the beach in Cleveland, OH... from my backyard in Buffalo NY!
Making a small movie of the Saturn system in rotation helped. I found the shadow first - a dark spot protruding from the shadow cast by the rings... and I was just able to spot Tethys as it passed against the darker tones of the planet's limb. The bright region at the northern edge of the equatorial zone that I first mistook for the moon is a storm. This bit of Saturn weather was an added bonus, as was the surprise appearance of the moon Rhea which emerged from the shadows just a moment before this image was recorded. All in all, a very nice ending for tax day. This year marks six years of saturn observations with my Astro-Physics 10" scope.
Astro-Physics 10" mak/cass and DMK21AF04 camera. Image processing in Astro IIDC and Adobe Photoshop.
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