My Photo

Rendition From
Mars Previewer II


Mars: This was taken on the night when Earth had its closest approach to Mars in eons, approximately 34.6 million miles. It shone at magnitude -2.9, the brightest object in the sky that night (there was no moon). Mars has a diameter of almost 4,220 miles (compared to the Earth's diameter of just under 8,000 miles); the apparent size of Mars at this time was 25.1 arcseconds, or about the size of a dime at 500 feet. From Seattle, Mars was only about 30 degrees above the horizon at its highest, so there was a lot of atmosphere to penetrate in viewing or imaging it.


Technical Information:

LRGB: I took hundreds of images through each of red, green and blue filters, and picked the best to process. R and G were .11 second exposures; B was .2 seconds.

Equipment: 10" LX200 at f/22.5, and an SBIG ST-8XE camera/CFW-8 color filter wheel.

Image Acquisition/Camera Control: CCDSoft V5.

Processing: No calibration performed; images aligned in AIP4WIN. Images average combined in Ray Gralak's sigma reject program. Fifteen iterations of Richardson-Lucy applied in AIP4WIN. Unsharp mask performed in Photoshop 6. Color combine, adjustment of curves, brightness and contrast performed in Photoshop 6.0.

Location: My yard in Redmond, Washington, elevation 500'.

Date: All images taken during the night of 8/27/03.

CCD Temperature: -18C

Moon Phase: New moon

Pixel Scale: .326 arcseconds per pixel

Copyright Mark de Regt, 2003