White Oaks Home | Sketches Index | Mars 2003 Index | Back | Next

Sketched July 26, 2003 from Glacier Point, Yosemite National Park midnight pacific DST (daylight savings time) or 07:00 UT. Outstanding observing night from 11:00 p.m. to 12:00 midnight. Transparency LM 6.8, seeing good (but not perfect).

Date: 07/26/03 Lat 37N, Long 119W, elev. 7,200 feet Sketch Time (UT): 7:00, (local time): midnight DST
Central Meridian: 7° Filters: none
Instrument: 7.1-inch (180mm) f/9 Astro-Physics Starfire Apo refractor. Distance from earth 0.44 AU, 66m km, 41m miles
Magnification: (16mm) 300x  Zeiss Abbe Orthos combined with a 2.4x AP Barcon Barlow Transp. 5-6/6, Seeing 8/10, Antoniadi (I-V):  II
Apparent Size: 21.3" Magnitude: -2.2

Note to self - sketching at a public star party is difficult, especially if you have the only 180mm refractor in town. We kept switching from diagonal to binoviewer and I go so mixed up as to what I was looking at that I settled on just one sketch at midnight. South Polar Cap notch and dark melt line continue to be prominent. I noticed a blue haze over the north polar area on July 25, 27, 28. Sinus Sabaeus and Sinus Meridiani continue to be the most visible areas. Everyone could see them.

Mars, in this sketch is reversed N/S. South is shown at the top of the image. The south polar cap is the prominent feature, and shows a notch that was quite distinct to me. Terminator is where daylight ends and evening begins. The terminator is on the left and the planet is rotating left to right. In my sketches the planet rotates martian east (left) to west (right) to match most other images and sketches. Look for features rotating from left to right in the drawings from night to night.

Details about Mars: Diameter 21.3 arc seconds (Jupiter is about 30 -50 arc seconds in diameter depending on its distance from earth). Central Meridian 7 - the imaginary line passing through the planetary poles of rotation and bisecting the planetary disk, and is used to determine the longitude during an observing session.

White Oaks Home | Sketches Index | Mars 2003 Index | Back | Next