Mars opposition of 2003 - Webcam images

The past couple of years have seen a true revolution in planetary imaging technology with the advent of inexpensive consumer Webcams, producing stunningly detailed color portraits of the planets. Although I had been playing around with the idea of buying a webcam and giving it a try myself already for several months, it took me till the middle of this year to finally make the step. Obviously, the very favourable Mars opposition in August of this year has been a key stimulator.

I acquired a Philips ToUcam Pro, which features a USB interface and a sensitive 640x480 pixel CCD chip. The device is capable of taking high-resolution 24-bit color streaming video. I also bought a 2x Barlow lens. 

I made my very first Mars video clip in the morning of August 24, 2003, using the Philips ToUcam Pro (without Barlow lens) in combination with the 35-cm SCT telescope of CBA Belgium Observatory, working at f/11. The seeing was of medium quality (Mars really doesn't get very high above the Belgian horizon these days). To display and capture my webcam images, I used the freeware program AVIedit, which is quite easy to use, yet powerful.


One can easily recognize the bright South Polar cap and the Mare Erythraeum / Sinus Meridiani regions.

Mars on August 24, 2003. Equipment used : Celestron C-14 SCT at f/11 and Philips ToUcam Pro webcam at 640x480 resolution.

Post-processing of the Webcam images (including aligning and stacking of images, selective integration of images obtained under better seeing) was done using the freeware program Registax, which is really a marvellous piece of high-precision software. The final  image was then refined using Paint Shop Pro's unsharp masking function.

I realize that my images are not top notch quality, but for first trials they don't seem to be too bad. Also, one should not forget that Mars is not favourably placed in the Belgian sky, due to its low altitude.

On the morning of August 31, 2003, I made a second attempt to make webcam images of Mars. The equipment used was the same as described above, but this time I used a 2x Barlow to obtain an even higher focal ratio (f/22 instead of f/11). The seeing was quite moderate, so the resulting image is not very sharp. 

The image clearly shows that the South Polar cap has already started to melt (compared to 6 days ago). The dark region in the center of the image is famous Syrtis Major with Mare Thyrrenum to the right and Mare Serpentis to the left. Note also Hellas to the south of Syrtis Major.

Mars on August 30, 2003. Equipment used : Celestron C-14 SCT at f/22 (2x Barlow) and Philips ToUcam Pro webcam at 640x480 resolution.


Another attempt to "webcam" Mars was made on September 4, 2003 (morning), using the same equipment (without 2x Barlow lens). The seeing was quite bad. The resulting image is shown at right.

The South Polar cap has continued to shrink, and now has almost disappeared. The dark region towards the left border (East in reality) is Syrtis Major, followed by Mare Thyrrenum. Next comes Syrtis Minor with Mare Cimmerium.


Mars on September 4, 2003. Equipment used : Celestron C-14 SCT at f/11 and Philips ToUcam Pro webcam at 640x480 resolution.




Copyright © 2003 - Tonny Vanmunster.