Mountains of the far side of the Moon

by Marek Cichanski

A quick OR from some semi-impromptu backyard observing...

I set up my mount on the back porch last night and parked the OTA under the tripod, in hopes of taking a quick look at the Moon this morning. When I got up at 6, there was some thin cirrus, but not enough to be too objectionable. I threw the OTA on the mount and gave the moon a look-see. 8 hours of thermal equilibration had eliminated any possibility of tube currents or thermal boundary layers in the scope :-)

Seeing was pretty good, I'd give it a 3.5 to 4 out of 5.

The main thing I looked at was Mare Orientale. It appeared to be very favorably librated. The sun was mostly overhead at that location, but not entirely. I was able to see a fair amount of detail in the Orientale region. I could clearly see both Lacus Veris and Lacus Autumni, which are small lava plains that partially fill the low annuli between Orientale's mountainous shock rings. The shock ring mountains themselves didn't stand out much, due to a lack of shadow, but they could be seen in profile on the limb of the Moon. (These mountains are called Montes Rook and Montes Cordillera; the latter are named for the mountains of western North [or maybe South?] America.) The lava plain of Mare Orientale itself was also nicely visible - well, as 'nicely visible' as anything in the libration zone can be.

Most interestingly, I thought I saw some light-colored mountains on the far side of Orientale. They were barely visible, and they barely stood out from the limb of the Moon, but they weren't just an artifact of the seeing. I thought this was pretty cool. I was seeing the Moon's most spectacular multi-ring basin, which is usually invisible because it's in a libration zone. And I was lucky enough to see mountains beyond even this. So, in a sense, I guess you could say that they were mountains on the far side of the moon. Cool!

Copernicus was also beautiful, just starting to get kissed by the sunset terminator. Aristarchus was very light-colored, and I could just see Vallis Schroteri. Gassendi was also nice. I wished that I could have spent more time looking at features amongst the vast plains of flood basalt that make up the western Imbrium / Procellarum area.

I don't know if it'll be clear tomorrow morning, but if it is, y'all might want to take a peek at Orientale. It's pretty cool.