Lava Flows near Mons La Hire and the Dorsum Zirkel

[John]

Lovely moon tonight as reported excellently here by Piero

I'll only add a short bit about my observations of the 1700m high Mons La Hire situated in the Western Mare Imbrium. When I turned my ED120 refractor onto the Moon earlier this evening I noticed this mountain casting a really long and striking shadow right across the mare to the nearby terminator. As the night has gone on this shadow has gradually shortened as the Mons crept further into the illuminated surface area. Mons La Hire lies close to the Zirkel Ridge (Dorsum Zirkel) and there are some very fine and quite interesting lava flows in this area. They are hard to spot and run at 90 degrees to the ridge looking rather like the gentle wavelets you get running up onto a shallowly sloping sandy beach. I found the easiest to make out were some that ran very close to a set of smaller peaks that lie between Mons La Hire and the terminator. I suspect the illumination has to be "just right" to pick these out because they are low profile features. 

Apparently these mark the furthest extent of the lava flows that filled the Mare Imbrium millions of years ago.

Lovely area this evening even if the flows elude you. I also just wanted to mention "Dorsum Zirkel" and "Mons La Hire" in a report - such wonderful names for geological features

Back to the eyepiece now to catch Uranus pale disk I think.....

Here is what Apollo 15 made of Mons La Hire and the Dorsum Zirkel - you can also see the lava flows:

 

[Piero]

That's a nice writing John. I was certainly not aware of it! There are so many details on the Moon that one could observe for a lifetime! 

Good luck with Uranus and with its moons!    Looking forward to reading your findings! 

I'm off to bed now as I'm having a busy day tomorrow. 

[Astro Imp]

Great write up John. Reading others' experiences adds to the enjoyment and to our knowledge. As Piero points out there is a lifetime of pleasure to be had from our neighbour.

[ronl]

I was also admiring Mons la Hire, the shadow was huge, it reminded me of

the Burj Khalifa in Dubai, there is a photo of it from above with the shadow

stretching out for quite a distance, the Moon was very impressive last night.

We had our first frost, which is very promising, always good seeing with frost.