Last night I was treated to another great view of Mars by my TV-102 and 4mm Radian. The seeing was about average, but improved somewhat as time passed. The CM was about 270 degrees, and Syrtis Major, Mare Tyrhenum, and Mare Cimmerium were all very dark and prominent. With no filters, there was a distinct blue-green haze around the north pole, and the dark regions of the planet actually looked slightly blue-ish gray. The lighter desert areas appeared more of a washed- out salmon color, while the tiny ice cap at the south pole remains a stark white.
I made a sketch of this magnificent view, which unfortunately does not do it justice. (Scanning & JPEG compression didn't help, either.) For what it's worth, though, the sketch can be found here.
There is one thing in particular in the sketch that surprised me: In addition to the normal dark regions that I am used to seeing, I saw a very dark, round spot and a medium-dark "arm" between Mare Tyrrhenum and Hellas. It is hard to tell from my scanned sketch, but this spot was about the same intensity as Mare Tyrrhenum, while the arm leading to it was not quite as dark, but still darker than the surrounding area. I checked the internet the following morning, and indeed I saw the same feature in some of the recent sketches & photos. Does this feature have a name? It doesn't show up on the maps from Sky & Telescope.
[Note: See also the follow-up observation and gorgeous color sketch by Ron B(ee) here.]
Clear skies,
Neil