Rimae Sirsalis, Darwin and Crüger

[John]

Some wonderful lunar views tonight with my 130mm refractor

Rich detail of the terrain visible along the terminator of the 97.7% illuminated disk.

The Rimae Sirsalis was easy to pick out running for over 400km across and between craters, mountains and plains. A little more challenging was the Rimae Darwin which bisects the crater of that name near the prominent, smooth floored Crüger and eventually appears to join with the Rimae Sirsalis, at right angles to it. The floor and walls of Darwin Crater might be best described as chaotic with a wide mixture of terrain visible besides the Rimae. Crüger on the other hand has a really rather smooth and noticeably darker floor and well preserved ramparts.

I can't recall observing this particular crater and rille before. The conditions allowed 300x - 400x to be used rather effectively.

Apparently the Rimae Sirsalis is not only the longest rille on the Moon but also the site of the strongest magnetic anomaly.

Here is a link to a very nice photo of this area by Brian Donovan:

http://www.donovanimages.co.nz/media/astrophotography/lunar-craters/Darwin-Cruger-de_Vico.html

And a link to a nice piece on the "Cloudynights" forum by Tom Glenn on observing this part of the Moon:

https://www.cloudynights.com/topic/640281-observing-guide-to-rimae-sirsalis-the-longest-rille-on-the-moon/

 

 

Edited February 26, 2021 by John