[AZ-Observing] Mars This Morning

Most of this morning the northern third and southern quarter of Arizona 
was cloudy, but Phoenix experienced a clear sky from horizon to horizon.  
The dewpoint was 62F with corresponding bad transparency, but the seeing 
permitted a magnification of 350x on the red planet.

The central meridian at 2:30 a.m. these days is about 15 degrees.  This 
puts Sinus Sabaeus toward the gibbous limb, and Mare Erytrhraeum near the 
center.  I have to admit that albedo features on Mars do not excite me as 
much as dynamic features such as those on Jupiter.  I am learning that 
Mars is dynamic, though.  There were no obvious clouds apparent, but the 
usual haze on the "non-gibbous" limb showed up brightly.  The South Polar 
Cap has been interesting to follow since April.  It has shrunk noticeably 
since my last time out (yikes, over a month).  An coordinate grid overlay 
sequence posted on the 'marsobserver' group shows it shrinking from a 
latitude of 60 degrees south to greater than 70 degrees south during that 
period.

One part of the cap has extremely high albedo, appearing overexposed even 
to the visual observer.  Near the gibbous limb is a small gray notch in 
the cap.  This feature is saturated on every image of Mars that gets 
posted.  Speaking of images, the visual view was a refreshing change from 
a month of virtual viewing of terrific images by Grafton, Parker, Peach, 
et al.  While all of those images show striking detail, none of them 
begin to convey the experience of actually looking at Mars through the 
eyepiece.  Again, visual observing rules.

Tom

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