The Mars 2007 Opposition -- Notes & Images
This webpage is a log of my observations and images of the Mars 2007
opposition. These observations were made with a pair of 6 inch telescopes.
The drawings are renderings made with the Gimp, a freely available drawing program available for Linux and Windows.
I happen to use the Linux version of the program. As a computer scientist
by trade, I'm attracted to the Linux system because of its modularity,
robust design, and too numerous to imagine utilities.
|
|
My drawing procedure is to make a rough sketch with notes at the eyepiece,
then use the notes and sketch to better render (with the Gimp) what I
observed.
The best opposition I've ever had the pleasure to observe was the 2003
opposition, when Mars reached a whopping 25 arc-second apparent size. My
sketches of that opposition are presented on the 2003 Opposition webpage.
On this, the 2007 opposition, Mars only gets to 16 arc-seconds in apparent
size. I doubt that I will see the details available during the 2007 opposition,and my have little luck in trying to photograph Mars with my modest equipment.
None-the-less, some details can still be seen with amateur sized telescopes.
For this opposition, the prime instrument is my 6 inch f/10 planetary DOB,
reviewed on the Stargazer Steve DOB page.
|
I'll also be using, for comparison purposes, my 6 inch f/5 Discovery EQ
telescope, reviewed on the Discover EQ page.
If you're not geared up for this opposition, it will still be visible
through December 2007 and January 2008. The best type of telescope will
have a long effective focal length, like a long focus refractor, a Maksutov,
or a Schmidt Cassegrain. You can also use a medium to long focus Newtonian
reasonably effectively.
|
Find an adequate planetary refractor, cassegrain, or long focus Newtonian
with this astro-customized search:
|
|
|
|
First Observation -- 12/02/07
Shown at left is my first effort at seriously observing Mars on the
2007 opposition. Mars was about 15 arc-seconds in apparent size, near the
maximum for this opposition.
For this drawing, I used my 6 inch f/10 planetary DOB with a single
screen apodizing filter (to cut down brightness). The magnification was
about 250x.
|
Transparency was 10, and seeing about 7. The seeing was primarily due to
Mars still being at a fairly low elevation of 30 degrees. In my observing
location, there are mountains to the East, and these cause considerable
turbulence from their retained heat at low elevations.
I've installed a PC fan in the bottom of the telescope, and I let this
run for about an hour prior to observing to cool and stabilize the
telescope. I don't believe any of the observed turbulence was due to the
telescope itself.
The drawing is in the inverted view as delivered by my DOB telescope.
As you can see, I could make out some dark regions at the top (South) part
of Mars with a whitish area at the pole.
At the bottom (North) portion of Mars, I could see a more extensive
whitish area, with a rim of darker material. Over the planet proper I couldn't
make out any details.
|
Observation -- 12/04/07
I had another opportunity to observe Mars on Dec 4. Seeing was about 7 to
8, transparency 9 or 10.
I was using my f/10 planetary DOB at about 250x.
Details were very faint and fleeting given the variable seeing.
|
|
I tried to use my ETX 90 and a digital camera to capture an image, knowing
that it would be difficult given Mars' apparent size. I could tell that getting
a big enough image was going to be hard, and it proved too much. Also, the
digital camera didn't offer any brightness or contrast overrides.
I'll have to resort to my old webcam with barlow projection technique.
Taking pictures of Mars on the mediocre opposition will be a challange.
|
|
Watching Mars, as always, is fun no matter what. I may try my red filter on
the next outing. Since the dark areas are showing so faint, the red filter my
help darken them.
|
If you haven't tried filters, you may find they give just that additional
contrast you need. Use this astro-customized search engine to find eyepiece filters.
|
|
|
Observation -- 12/20/07
Some good weather for a change caught up with me on the 19th and 20th of
December.
I managed to lay my hands on an old Dell laptop and got it configured with
Etch, the stable version of Debian Linux. There are a number of webcam programs
in Linux, so on the 19th I took my shot at setting up the laptop and my webcam
for some Mars photography.
Sorry to say, it was a wash. The webcam software I was using didn't seem
to turn off the auto-gain, and Mars was being totally over exposed by the
camera's auto-gain logic. I'll be trying to find a solution to that.
|
On the 20th, I drug out the 6 inch f/10 planetary DOB, and make another
sketch, as shown in the image at left.
Seeing was about 8, transparency 9. Magnification was about 250x.
The details were very low contrast, but I was able to improve that by
observing through a red filter. The contrast drawn is more like I saw with
the red filter.
Seeing caused the details to come and go a bit, so the extensions off
of the main dark area (Syrtis Major) were not distinct, and just seemed to
trail off to the limbs of the planet.
| 
