Mars through the Fog

Mars through the Fog December 19th, 2007
By Frank McCabe

 Initially this observing night began iffy at best. A layer of mid-level thin
clouds along with some ice fog made the view of the moon poor in contrast. Both
Mars and the moon took turns appearing and disappearing behind clouds. When I
caught a look at Mars through the fog I realized the transparency although poor,
was improving the seeing of the Martian low contrast features in a positive way. I
was able to use a 4mm orthoscopic ocular at 360x on Mars for sketching. I tried
several filters but the fog was providing the only filter I really needed.
  The central meridian was 341° and the planet was nearly 100% illuminated. The
angular size of Mars on this night was 15.9” of arc. Mars was shining through the
clouds at magnitude -1.6. No stars below 3rd magnitude were visible. The most
prominent features visible included: the bright North Polar Hood; and the
following dark features: Syrtis Major about to rotate out of view; Iapygia
Viridis; Mare Serpentis; Sinus Sabaeus; and Sinus Meridiani. This was my first
Mars sketch in two years.
  
  Sketching: White sketching paper 9”x 9”; 4H, B, HB, and 2H Graphite pencils; I
  used my fingers for blending.
  Date 12/19/2007 – 4:30-5:00 UT
  Telescope: 10 inch f/5.7 Dobsonian and 4mm eyepiece 360x
  Temperature: -3°C (27°F)
  mostly cloudy, fog, calm
  Seeing: Antoniadi II