Comet C/2013 A1 Siding Spring at Mars
Taken on the evening of Oct 19th about 8 hours after Siding Spring's close encounter with Mars. The comet is at the end of right diffraction spike coming from Mars. (Mars being about Mag 1, Siding Spring about Mag 11.)
Single 180s exposure processed in Lightroom. Canon T3i prime focus with 6" F/9 1370mm Astro-Tech ritchey-chrétien astrograph plus Astro-Tech field flattener. Celestron CG-5 eq mount, and Orion Magnificient Mini Autoguider.