Lamont or How Not To Be Seen

[Nyctimene]

Wednesday 4.15 a.m., I took out the 8" f/4 Hofheim Traveldob for a short observation of Mare Tranquillitatis and Serenitatis. The seeing was bad, allowing mags of only 100x, sometimes 133x. When I was looking at the crater Arago (25 km diam.), the smartphone app "Lunar Map HD" showed close by the name "Lamont", and described a crater structure of about 75 km diameter; but at first glance, I was able to make out only very faint features of it in the map. Trying to spot Lamont with the scope, NE of Arago was likewise difficult. After some minutes of looking (tried even averted vision - completely senseless), and comparing with the map, I finally spotted a rather large, circular formation, that looked like an almost completely sunken old crater, with most details close to Arago; very unimpressive in contrast to Arago's terraced crater walls. - Rimae Sosigenes were completely invisible; and the Rimae Ariadaeus and Hyginus views suffered from the bad seeing; so I finished the session after some short looks at Rupes Altai and the crater trio Theophilus, Cyrillus and Catharina at 5.00 a.m.

Doing a little research later (Rükl 35; https://the-moon.wikispaces.com/Introduction

I learned, that Lamont is considered not as a crater, but as a "peculiar concentration of concentric and radial ridges, thought to mark the location of a buried ancient impact basin, about the size of Grimaldi, which reveals itself as an anomalous concentration of mass ("mascon") in gravity maps". So, despite it's inconspicuousness, an interesting area. And, as I discovered finally, No. 53 of the Lunar 100.

Attached a picture; Lamont is just above Arago (the distinct crater slightly left to the middle)

Thanks for reading

Stephan

 

[domstar]

Beautiful. I'm too much of a sleepy-head to observe the waning moon.

[Nyctimene]

5 minutes ago, domstar said:

Beautiful. I'm too much of a sleepy-head to observe the waning moon.

Well, ---- sleeplessness is one of the few drawbacks of getting older, that you can make use of!

[MarsG76]

Nice scientific write up... I enjoyed reading your report.

[pbyrne]

Lamont needs low illumination to be seen at its best, to me it always looked like a spider that has been stepped on.

Nice report.

[mikeDnight]

What a great report Stephan! Even though the seeing was poor you still managed a worthwhile observation, and the research you did makes the whole thing even more interesting. This will be something you'll remember forever! I love the image too! 

[Eastman]

Again Stephan, great report on a interesting Lunar part!

[Trikeflyer]

Thanks for sharing. Very interesting.