Mars Opposition  (August 2003)

Mars through a telescope from the driveway of our house in Cockeysville, Maryland on 2003 Aug 24 23:45 EDT (2003 Aug 25 03:45 UT).  The apparent magnification of this image is about 700X. Relative position of Mars and Earth during oppositions in the recent past and near future.  (Source: Dickinson T, Dyer A. Backyard astronomer's guide. 2nd ed. Buffalo (NY): Firefly Books; 2002. p. 195.) What the first photo would have looked like if it were taken from a space probe orbiting Mars (a lot closer than from our driveway!). (Source: NASA)		Historic Astronomical Event Every 26 months, Mars and Earth line up on the same side of the Sun, an event called an opposition.  During these events, Mars is closest to Earth and appears largest.  But even during an opposition, the actual distance between Mars and Earth is highly variable because Mars' orbit is quite eccentric.    A Mars opposition occurred on the morning of August 27, 2003.  This opposition was historic because Mars was closer to Earth than it had been for nearly 60,000 years, since the time of prehistoric humans, mastadons, and sabre-toothed tigers.    We had been observing Mars during every clear night in August 2003.  It appeared as a striking, bright orange "star" in the southern sky a couple hours after sunset.  Unfortunately, August 2003 was quite rainy and humid in Baltimore, which limited the amount of detail visible through our telescope.  But two nights before the opposition, the weather cooperated, and we were able to take the picture shown here.  Mars' south polar ice cap is clearly visible, as is a number of its dark surface markings. Warning:  The Following for Nerds Only Our photo of Mars took a bit of luck to make.  After several disappointing attempts to image Mars with a camcorder and digital camera, I read about how some amateur astronomers are using webcams to photograph the planets.  I happened to have a webcam in my junk box (you never know when you will need one).  I took it apart and adapted it for use with our telescope, with the help of some plumbing parts from Home Depot and a lot of electrician's tape.    We first tested the modified camera a couple nights before the Mars opposition, and it worked!  That night also turned out to be the best night in weeks for observing Mars because the air turbulence was relatively low.  If you want to know all of the gory technical details, see below. Telescope:  Celestron C9.25 (235 mm aperture, 2350 mm focal length) Telescope mount:  Losmandy GM-8 equatorial mount with digital clock drive Camera:  Connectix QuickCam VC webcam with 320 x 240 pixel color CCD chip Camera coupling:  Positive projection with 26 mm Meade Super Plössl eyepiece yielding an additional 2.5X magnification Data acquisition:  Approximately 600 frames at 10 frames/second Image processing:  Selected the sharpest frames (65 frames selected) and combined them with the Registax program.  Mild resolution enhancement with wavelet filtering in Registax.  In Adobe Photoshop, adjusted the image's color balance, contrast, aspect ratio, and orientation. ( back to home page)
Update  (September 2003) The weather in Baltimore cleared the week after the opposition.  Since the Martian day is 24.6 hours long, the rotations of Mars and Earth are not synchronized.  Therefore, the visible portion of the Martian surface is slightly different from night to night from Earth.    The equipment setup was the same, except we used a webcam with higher resolution and an eyepiece with higher magnification.  However, the overall apparent magnification of the final image is approximately the same. Camera:  Orange Micro iBot webcam with 640 x 480 pixel color CCD chip Camera Coupling:  Positive projection with 15 mm Meade Super Plössl eyepiece inside Meade tele-extender Data Acquisition:  175 frames at 30 frames/second Image Processing:  Selected the sharpest frames (23 frames selected) with processing similar to previous image		Mars through a telescope from our driveway on 2003 Sep 6 00:31 EDT (04:31 UT).   What the photo above would have looked like if it were taken from a space probe orbiting Mars.

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