Lunar Sketch 7 of 12: Sinus Iridum

Good morning all,

I hope this post finds you and those close to you well. I am pleased to share with you the 7th installment of my lunar sketches - only five to go! Something tells me though that I'm going to keep up the activity once December comes! I am thoroughly enjoying sketching the Moon whenever I get the chance to. And on that...

July was another poor month for astronomy - I only manged four sessions all month because the weather was poor. Consequently, I had only one opportunity to sketch the Moon. That was last Thursday at my sister's house in Baltinglass Co. Wicklow.

According to the 'Clear Outside" website my sister lives under a Bortle 4 sky - Needless to say, I was looking forward to observing from her place. When I arrived at 23:11 IST, the sky was cloudy, but Jupiter was visible. I set up the scope in her SW facing back garden, where my sister, her husband, my Dad, and my niece and nephew observed Jupiter, the Moon, Saturn, M13, and Albireo. By 01:00 IST the sky improved. The Milky Way was visible, and the sky looked magnificent. As it was my nephew's 11th birthday there was plenty of food to keep us going until the early hours

As it ended up being a more of an out reach type of event, I did not sketch the lunar surface at the eyepiece. Instead I sketched Sinus Iridum yesterday. We observe this feature on Thursday night. My family were blown away by the beautiful area of the lunar surface. Being honest, they loved the entire Moon. So much so, that my brother-in-law is now on the look out for scope for the family. It was a great night, and it was nice way to mark my nephew's birthday.

Other details from that evening include:

Location: Baltinglass, Co. Wicklow - Bortle 4
Seeing: 4pk
Transparency: 3/4
Instrument used: f/5 250mm Newtonian Reflector
Eyepiece: 6mm Expanse (66° AFOV)
Materials used: 8B pencil, 2B, and an eraser. The image was sketched from a photo, and cropped and reszied using GIMP 2.0. The sketch was scanned, and uploaded to my PC.


As always many thanks for taking the time to read the above, and your comments and feedback are always welcomed.

Clear skies to all,

Darren.

Thank you for this delightful portrayal of Sinus Iridium, Darren. 
I see you have included the craters Bianchini + G, Helicon, Le Verrier, Promontorium Heraclides and Promontorium Laplace. 
You also have Laplace A here. 
This latter crater proved particularly difficult for me to figure out from Antonin Rukl's Atlas of the Moon. 
But an independent website helped me out. 
The other tiny crater could be Heraclides E. 
But I'm not sure about that one. 
The 2 craters Sharp + A look very good indeed.  
That crater below Bianchini appears to be Bouguer. 
It's right on the terminator in your excellent sketch, Darren. 
Montes Jura look superb. 
They must have been very spectacular on your Thursday night through your 10" reflector!
Thank you for providing us with this very fine sketch. 

Clear skies from Aubrey. 

Hello Aubrey,

Lovely to hear from you. Very many thanks for your message, and for looking up those details about the lunar features. From my virtual Moon Atlas, I believe you are correct about Hercalides E because I have included another smaller crater just below it that seems to be Heraclides 4.

And based on the Virtual Moon Atlas, I don't think I captured Sharp or Sharp A - of course I stand corrected, but you are right in saying that I sketched Bougeur.

Apparently he was a French Geophysicist who in 1735 went on mission to Peru with La Condamine (whose crater is also included in the sketch) to discover anomalies in the field of the Earth's Gravity. According to the Virtual Moon Atlas, he i.e., Pierre Bougeur invented the heliometer - I had to look up what was a heliometer!

When I observed this area of the Moon last week I was struck by the irregular shape of 'Maupertuis'. Based on its dismantled shape I assume it is a relatively older crater?

And your're right too about how pretty the Moon looked last week. It was fairly low in the sky when I observed it, and it had slightly faded orange hue to it. It look very nice indeed!

Clear skies,

Darren.