Gauss and Humboldt

[Nik271]

Last night I observed these two craters on the western limb. I don't recall spotting them before, perhaps because I rarely observe the full Moon.  I concentrated on the western limb since the rest of the Moon looked flat. I was using a Svbony 20mm giving 135x on Skymax 180. I quite like this EP, it has wide FOV and does not ghost on bright objects unlike its shorter focal length cousins from the same range.

Gauss was a prominent large crater on the limb just north of Mare Crisium, with two smaller craters, Hahn and Berosus nearby. It was very foreshortened with little detail visible but thrilling to see it anyway.

Humboldt, south of Mare Fecunditatis was more spectacular - it has a central mountain ridge which was catching the sunlight while the floor was in darkness. Next to it to the north was another oblong crater which I could not identify, maybe Catena Humboldt?

This all took about 20 mins. Normally I try to stay a bit longer but there was a lot of high cloud and even the Moon views lacked contrast so I called it a night hoping for better luck early in the morning ( I looked at some double stars then in a separate report). 

 

Nikolay

 

 

 

[Stu]

Lovely report @Nik271. Sounds like we were observing the same thing last night, although I was only using my little 63mm peashooter. It was very interesting identifying those craters right on the tiny terminator. Did you catch Mare Humboldtianum on the upper limb? Looked good too.

[Stu]

@Nik271

This is Humboldt I believe, with the peaks you were referring to.

[Nik271]

2 hours ago, Stu said:

Lovely report @Nik271. Sounds like we were observing the same thing last night, although I was only using my little 63mm peashooter. It was very interesting identifying those craters right on the tiny terminator. Did you catch Mare Humboldtianum on the upper limb? Looked good too.

 

Unfortunately I missed it, probably focused too much on Gauss. Now I wish I had spent more than 20 mins observing....

[Nik271]

2 hours ago, Stu said:

@Nik271

This is Humboldt I believe, with the peaks you were referring to.

That's right, the ridge was exactly this and it was very bright. I also noticed the crater above it and I wonder what it is. I suspect it it Catena Humboldt but Wikipedia refers to is as a sequence of craters, whereas I only saw one, as in your photo.

[Nik271]

I did some more careful investigation and realized that I have misread the labels of the moon atlas I'm using 😞

The second crater is is not Catena Humboldt but Hecataeus. Catena Humboldt should be a sequence of small craters and I doubt it can be seen at all.