Take a look at my sketches of Mars. You'll notice that I always include a rating on how good the seeing is. Some sketches include a rating of 4 - 4.5 (on a scale of 5, but some observers use a scale of 10). Several things conspire to cause my estimates of seeing based on how well I can see details on the face of Mars. When I rated the seeing at this level, there were roughly equal amounts of time when the view was moderately to very clear compared to the amount of time when the view was fuzzy. Only by spending at least 10 to 15 minutes can I make a good determination on how good the seeing is. On the occasions when I rated the seeing at 3.5 - 4, I struggled to see any details during those few and far between moments of clarity. On two occasions, I arose at the proper time only to choose not to make an observation simply because the seeing was lousy.
You'll notice that on those mornings when I did rate the sky as good to excellent, I spent more time at the eyepiece. I did this trying to work the scope to its full potential for the seeing conditions. I'd try my highest (408x) and next to highest (317x) power eyepieces (each power reflects that eyepiece used with a 1.8x Barlow lens) to see which one gave the best view that day. I'd also try different filters with each of those eyepieces. Filter choice is just as important as which eyepiece is too much power. Notice the choices of filter that I made from sketch to sketch.
The final, and probably most important reason for taking more time to view has to do with eye-brain coordination. It's a fact that the human eye can build up an image over time which equals and even surpasses the capabilities of film to capture fine detail in photographs. CCD images coupled with special imaging software is beginning to offer the absolute best images from telescopic observations, but that doesn't even require the operator to view anything. How can this possibly be considered to be enjoyable?
Sketching Mars or ANY celestial object will make a better observer of everyone who tries it. You'll notice that every object you see after learning to see more will be more detailed and more enjoyable for the rest of your observing days. If YOU will just try it, I'm certain you'll agree.
Make your own Mars Observation sketches. Just download your own printable copy of our official AOAS Mars 2003 Observers Log Sheet and get started!
For inspiration, have a look at some observations I've made of Mars recently:
12.5" f/7 Dob Mask(s) 6", full ap Filters: light red W23A
Eyepiece: 12.5mm Orthoscopic w/ 1.8x Barlow = 317x
Polar cap obvious; hint of markings @110x w/ full aperture; 6" mask helps; 1.8x Barlow helps; Best view is with 12.5mm Orthoscopic + 1.8x = 317x W23A light red filter reveals dark outline around polar hood w/ long, straight dark "bar" near center; possible limb haze on trailing (eastern) edge
Central meridian: SINUS SABEUS Distance: 78,771,000 mi
12.5" f/7 Dob Mask(s): 6" Filters: orange W21
Eyepiece: 12.5mm Ortho w/1.8x = 317x, 9.7mm Plossl w/1.8x = 408x
Not as good this morning; sky clear but air feels sticky; polar cap seems smaller; markings were hard to make out; W23A light red filter slightly too dark; orange filter best w/ 12.5; 9.7 used no filter; 6" mask for both
Central Meridian: SYRTIS MAJOR Distance: 72,540,000 mi
12.5" f/7 Dob Mask(s): 6", full ap Filters: orange W21
Eyepiece: 9.7mm Plossl w/1.8x Barlow & W21 orange filter = 408x
Excellent morning! Polar cap still obvious; dark outline around polar cap with dark protrusion almost to trailing limb; suspect dark all along terminator
Central meridian: MARE CIMMERIUM Dist: 68,541,000 mi
12.5" f/7 Dob Mask(s): 6" Filters: red W25
Eyepiece: 12.5mm Orthoscopic w/ 1.8x Barlow & W25 red filter = 317x
Morning clear but seeing only fair to good. Polar cap obvious and outlined by dark bands; moments of clarity show two distinct bands near cap, with a fainter diagonal band below and curving downward; clarity reveals a bright spot at the edge in the 4 o'clock position (Elysium)
Central Meridian: MARE SIRENUM Distance: 65,937,000 mi
12.5" f/7 Dob Mask(s): 6" Filters: orange W21
Eyepiece: 12.5mm Orthoscopic w/1.8x Barlow & W21orange filter = 317x
Morning clear w/crescent moon; very few moments of clarity; surface features fuzzy and fleeting; PC obvious but definitely shrinking, with broad dark area away from PC following radius of disk on trailing (eastern) limb; a moment of clarity reveals a darker "spot" near central meridian with a faint ext. to the west
Central Meridian: SINUS MERIDIANI Distance: 56,358,000 mi
