@ . . . . . Thank you for CMO 207, which arrived yesterday. I enjoyed the sketches and the analysis of them. You did well to point out that a relatively clear region of the atmosphere can make the ground under it, even the usual Martian desert, seem dark by contrast. This may be the explanation for some of the anomalous markings that have reported over the years, and it is another reason for viewing Mars with filters of different colors. An anomalous desert feature that darkens when viewed in blue would be an indication of a clear region of the atmosphere. Furthermore, although it may seem unnecessarily repetitive to say it one more time, if the Rima Tenuis turns out really to be a recurrent dust storm over the NPC, it would be helpful to use a blue filter to look for it. A blue filter would increase the contrast of a red marking seen against a white background. If the dust storm was in the atmosphere over the polar cap, then one should not be concerned that the blue light filter would not allow one to see to the depth at which the storm happened.
There are at least two good rationales for using filters. One is that the differential scattering of light at different wave lengths allows one to view at different levels, blue higher and red lower. The other is that using different colored filters allows one to manipulate contrast. A red marking will brighten in red and darken in blue, and so forth.
I would be glad to read any comments that you have about the above remarks. Consider me your willing and respectful pupil.
This afternoon we are taking Tyler to an ear specialist. Tyler will have tubes put in his ears surgically this coming Monday, in order to relieve chronic ear problems. David had similar surgery at about the same age, and he responded well to this treatment. I will be glad when Tyler has come through all this well.
A few nights ago I took Tyler out in the yard and showed him the Moon. He volunteered, "And there is Ju-pi-ter." Our weather is finally beginning to be cooler, but it is still quite dry. Not even the Virginia State Fair, which often has been spoiled by rain, brought us much precipitation this year. The swamp that I mentioned last time has almost completely dried up. The fish in the part of it that David and Tyler and I have been observing have all been lost.
I have looked at Mars a few times, but the image has been too small to make out details. There is serious talk of changing my work schedule back to what it was a year ago, which would be helpful by putting me near the observatory early in the morning, just in time for Mars. I hope that the change will be made.
Looking forward to Mars, I am
@ . . . . . I thought I would mention that the RAS site has a new web master and some new photos, including a couple of nice pictures of our old 7 inch refractor and the observatory itself. The RAS page can be found at
Tonight it is cloudy, with nothing interesting on TV, so I will turn in early. One of the nearby schools is loudly celebrating football or Columbus Day or something, with lots of yelling and beating of drums. We have a "white noise" machine for just such occasions, and I intend to use it. My good friend Maxie Wright, the one who will usually swear to the truth of any tall tale, became a grandfather last week. How the time does pass!
@ . . . . . I just thought I would say that Tyler made it through his ear surgery without any complications. This afternoon he was running around just like always.