More learning the moon

[The Warthog]

I set up tonight, as first reports indicated the seeing and transparency would be good. However, the humidity increased steadily through the evening, so I looked at the Moon exclusively. When I packed up, there was a misty quality to the streetlights that made them look warm and romantic, and as they don't interfere with lunar viewing, I didn't really mind them. The temperature was about 15 degrees, and there was no wind at all. The humidity tomorrow is supposed to be about 32%, but I'll believe it when I see it.

I got the moon in the scope before it was fully dark. I was using the refractor tonight. I am getting more and more happy with this scope. Since I put a 2" MV filter in the end of the diagonal, there is almost no CA, and the views are wonderful with it. Part of the time, I had it up to about 250x, which gave very satisfactory views, but mostly I observed at 125x, with my 8mm X-Cel, although I used other eps and ep + Barlow combinations during the night.

I also used my 20mm EWA ep, with a green filter which I find increases the contrast of the maria in the fully sunlit parts of the Moon. I did a general survey of the terminator with this combination, and spent quite a while comparing the view to the excellent maps in Ian Ridpath's "Pocket Guide to Astronomy," which are more than adequate for viewing at powers up to 250x.

It's a little more difficult than you would expect to identify things on the moon using a map. All craters are round, and two craters side by each can look like another pair side by each, so you have to look at the surroundings to come up with the right pair. Also, I have the problem that the maps are designed for a Newtonian, and I'm using a star diagonal, so I have to do some mental transpositions to figure out what's what. I started by nailing down Aristoteles (Aristotle, if you prefer) and Eudoxus north of Mare Serenitatis, and little Galle, just to the north of Aristoteles. South of Aristotle are the Caucasus Mountains, with a nice little crater, Callipus, right in the midst. Moving up the terminator (I'll be back...) I identified the wonderful combination of impact craters that is Hipparchus, Albategnius, Hind, Halley, and Horrocks (isn't Horrocks a chain of sweet shops?) A little north of that is some stuff that I'm still trying to name. It looks like the collection of craters that Walter is a part of, but is too small and in the wrong position, slightly.

When I got into the south, using the 8mm ep, I just gave up trying to name things, and gawked awhile. It's great fun, and time well spent, especially when you are trying to smoke an expensive Henry Clay Dominican cigar, drink a glass of ginger ale sweetened with rum, put your reading glasses on and off as you consult the map and then the eyepiece, and find the control stalks without looking.

Oh, yeah, I saw an occultation, too. I'm not sure what star it was, but it appears to have been a 5th magnintude star near rho Leonis, which I watched with great concentration as it got closer and closer to the limb, and disappeared at 10:36:06 by my watch. I've seen occulations on the bright limb, but this is my first on the dark limb, and I couldn't see the dark limb by earthshine, so I had to just watch and watch until it suddenly switched off. Along with the fact that laser surgery and proliferative retinopathy have created blank spots on my retina where point sources of light appear and disappear, it was a job of work to watch this. Makes up for the one I missed on Friday.

Two hours well spent, eh? Hoping for the same tomorrow. Should be looking at Rupes Recta then.

[geppetto]

Two hours well spent, eh

Yes indeed, last night's moon at that phase looked glorious.

Pleased you enjoyed it WH

[dazza1639]

Nice report WH, your reports are always a good read.

Darren