Observing Notes For The Mars 2003 Opposition
Cosmology 101 Items',
This page presents Mars drawings made during the 2003 opposition. Mars was
observed with a 6" f/10 Dobsonian designed especially for planetary
observing by Steve
Dodson. Also included is one composite of a Mars sketch and photograph
showing their correlation. The photograph is a 48 stacked image taken with a
Quickcam Express Webcam through an ETX 90.
Mars has always been my favorite object. I still remember on night over 30
years ago when conditions were just right, and my old 6" f/12 was giving
the best views ever. I stayed up pretty late that night, much to the
consternation of my folks. I was always most intrigued by the stories
of Percival Lowell and the construction of the Lowell observatory in
Flagstaff, Arizona. I was there a few years ago, and wanted most of all
to see the famous 24 inch refractor. I went there, but the place was jammed.
Oh well, maybe next time.
The above images were drawn on the indicated dates, and reveal
the rotational period difference between Earth and Mars, as indicate by the
moving position of Syrtis Major
I'm not highly experienced at sketching at the eyepiece, but I've made
a few moon crater and planet sketches over the years. I enjoy sketching
Mars the best, and it's probably because I enjoy looking at Mars the best.
I agree with many other sketchers that drawing what you see through your
telescope makes you a more critical observer. Soon you begin to see details
that escaped you before you began sketching.
For these Mars sketches, I used just a drawing tablet, a number 2 pencil,
and a smudge stick. Before I went out, I used a 2 inch diameter bottle cap
to draw a circle to represent the planet. I made the sketches of Mars within
the circle. On occasion I also used a red filter which helps enhance
I started by observing first for major features, and then outlined lightly
these features. When these were all outlined, I shaded them in. Then I
began the critical examination phase to seek out any details I could discern.
My greatest obstacle was my glasses. I don't use them when looking though
the telescope, but must use them to draw. It made the procedure certainly
more cumbersome than in my youth.
Since the 2003 opposition, I've added a muffin fan behind the main
objective. I've found that the muffin fan, removed from an out of service
computer, is vibrationless and pushes quite a bit of air.
I've only began to test the arrangement, but it appears that best use is to
leave the fan on while observing. When the fan is on, it disrupts the layer of
turbulent air that boils over the mirror surface, and leads to significantly
improved views. I look forward to using the scope with this enhancement this
The Planetary Dob
The telescope pictured above is the specially designed planetary scope
used for observing the Mars 2003 opposition. The telescope is a 6" f/10
Newtonian on a Dobsonian mount. The instrument was designed as a kit by
Stargazer Steve Dodson.
The scope mount is a low-profile design, made
possible by adding counterweights to the uniquely designed mirror mount.
The telescope uses an oversized tube to keep air currents away from the
Field of View.
The secondary is small due to the long focal length, and mounted on a single
element, curved vane. This eliminates spikes normally caused by a conventional
You can contact Steve about purchase of one of his telescopes at Steve Dodson.
The composite above shows a drawing made using the 6" on September 10,
and a CCD image taken through an ETX 90 on September 12". The CCD image is a
stack of 48 single images. The composite indicates both the remarkable
capability of the ETX 90 for such photography, and the accuracy of the
This composite is based on the same ETX 90 photo, but with
some Martian feature labels for reference.
Other Targets: Comet 17P/Holmes
I primarily use the instrument described on this page for lunar and
planetary observing. As described, the telescope has features especially
designed for that purpose.
That is not to suggest the telescope has no other use. It is a good
instrument for a wide range of observing. It just isn't optimal for
wide field viewing.
As an illustration, I used the telescope to view comet 17P/Holmes in
2007, a couple of weeks after it appeared to explode. At left is a
drawing of how 17P/Holmes looked on October 29, 2007.
Check out the Holmes Comet page for more observations and sketches.