Sketched August 7, 2003 from my back deck 2:15 a.m. pacific DST (daylight savings time) or 09:15 UT. Poor but usable observing conditions, from 2:00 a.m. to 3:30 a.m. Great transparency - I could see the Milky Way overhead in Cygnus, but it was windy, cold (for California) in the low 60's. The wind shook the small refractor some. The wind made for poor seeing, with little steadiness in the view of Mars at high power. I tried Red #25, Orange #21, blue #80a and #82a blue filters, and also the Orion variable polarizing filter, and each, in turn helped bring out subtle features.
|Date: 08/7/03 Lat 37N, Long 122W, elev. 200 feet||Sketch Time (UT): 9:15, (local time): 2:15 a.m. DST|
|Central Meridian: 291°||Filters: Orion Variable polarizing filter 1% - 40% transmission and Red #25, Orange #21, blue #80a and #82a blue|
|Instrument: 4-inch (105mm) f/6 Astro-Physics Traveler Apo refractor.||Distance from earth 0.40 AU, 60m km, 37m miles|
|Magnification: (6mm) 252x (10mm) 151x Zeiss Abbe Orthos combined with a 2.4x AP Barcon Barlow||Transp. 4-5/6, Seeing 3/10, Antoniadi (I-V): III - IV|
|Apparent Size: 23.4"||Magnitude: -2.5|
Mars, in this sketch is reversed N/S. South is shown at the top of the image. The angular dark feature below Hellas is Syrtis Major. The long dark feature crossing east to west limb (left to right limb) is Sinus Sabaeus and Sinus Meridiani, on the zero meridian of longitude. On the east side is a faint view of Mare Cimmerium with Mare Tyrrhenum south (above). Between Syrtis Major and the lighter round Hellas basin is Apygia and the snakelike dark albedo feature south of Sinus Sabaeus is Mare Serpentis. The terminator is where daylight ends and evening begins, and the phase, nearing opposition is 97% illuminated right now. 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 23.4 arc seconds (Jupiter is about 30 -50 arc seconds in diameter depending on its distance from earth). Central Meridian 291 - 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