On October 19th, 2014, Comet C/2013 A1 Siding Spring passed Mars at a distance of 132,000 km, roughly 1/3 of the distance between the Earth and the moon. While it was cloudy here on the 19th, the day before and after still gave us a chance to catch an image. This was a challenge because the image was taken between 15 and 10 degrees above the horizon.
Luminance – 12x75s – 15 minutes – binned 1x1
RGB – 3x75s – 3.75 minutes each – binned 2x2
18.75 minutes total exposure
Imaged October 18th, 2014 at the Danville Conservation Area (New Florence, Missouri) with a SBIG ST-8300M on an Astro-Tech AT90EDT at f/6.7 603mm. This data was acquired by Dan Crowson (https://www.flickr.c...hotos/dcrowson/) and processing by Gregg Ruppel.
LRGB Composite - https://www.flickr.c...0729600/sizes/l