3 shades of grey
Three days of clear (enough) weather in The Netherlands somehow means there’s also a moon out. We haven’t seen a new moon in about 3 months now. But I needed to testdrive my dobson after some changes to it and the guide Objects in the Heavens v6 inspired me to go and look at some sites on the moon.
The 14th of February I looked at the following sites:
- Copernicus, brightly lit rims and the rays were very obvious;
- Tycho, less impressive but what a sharp and deep crater it is;
- Clavius showed some craterlets, quite a bunch actually!
- Saw the shield volcano, the Hortensius dome;
- Lambert R, a ghost crater (he’s half the crater he used to be…);
- Couldn’t make out Hesiodus A at all…
Also, I noticed the different shades of grey on the moon. It’s not 50 of them but only 2 or 3.
After removing the piece of blue plastic on the mirror (apparently left there after collimation on the 13th) I set out for:
- Gassendi and it’s fractures on the floor;
- Long oval-y crater Schiller;
- 2 small lava domes Griuthuisen Delta & Gamma;
- Flamsteed P which is an old crater with it’s walls torn down by gravity;
- the Imbrium lava flows were hard to distinguish but I think I’ve seen them.
Seeing on this evening was marvelous at 1.05 arcsec, which is *really* good for our location. The 14th gave 1.36 which wasn’t bad too. Yesterday I noticed a wobble of the OTA in it’s rockerbox mount because of which it was hard to manoeuvre the telescope. Also the focuser needs new grease as it doesn’t move freely.
The 16th I fixed the wobble in the telescope and I collimated the telescope again. After cooling the telescope down I looked at:
- Vallis Schroteri and it’s meandering lava channel. Forgot to see if I could make out the rille on the channel floor;
- The Aristarchus Plateau has multiple pyroclastic fields but since I don’t know what those look like I couldn’t ID those;
- Schickard wasn’t all to fascinating;
- The Marius Hills indeed look like a … hilly area with some domes;
- Mersenius is a flooded crater with craterlets M (5km) and N (3km!) clearly discernable at 250x through the Baader orthoscopic eyepiece;
- Reiner Gamma looks cool in pictures but visually not so much (or maybe I was looking at the wrong site ^_^ ).
And that was that. Three clear nights out in the garden is an easy achievable way to spend this hobby. Two minor and one major improvement on the telescope have popped up. First of all I really need to change the grease on the focuser. That’s major. The other things are mounting the OTA in the rockerbox with bolts instead of screws (which was temporary anyway) and the three stands for the rotating platform are made of rubber which (duh….!) makes the whole thing terribly wobbly when focusing. I hope that’s the only cause of the wobble, the other could be the whole construction being a bit out of balance and that’s harder to fix.
All pictures were taken through the eyepiece with an iPhone 7 at 136x magnification.