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Craters Near to the Limb in the South Polar Region

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#1 frank5817



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Posted 01 February 2009 - 03:18 AM

With the lunar South Polar Region tilted towards the earth it was a good evening to take a look at the craters positioned where the terminator meets the southern limb. The most notable craters I was able to see well and sketch were two large Nectarian period craters. The western most is crater Amundsen (108 km.) named for the first Antarctic explorer to reach the earth’s South Pole. Its far wall was well illuminated by sunlight and low central peaks could be seen during brief periods of improved seeing. Just to the north the other crater named for an Antarctic explorer, Scott (110 km.) was seen but the floor was mostly in shadow especially to the east. To the east northeast of Amundsen the crater Demonax (115km.) named for the second century philosopher was the easiest of the three craters to see in the morning light. Sixteen kilometer Demonax A could be viewed on the south floor near the far rim of this crater and the southwestern worn rim of Demonax was brightly illuminated in the low sunlight. Additional small craters were visible on the outer north rim. The sky was beautifully clear at the time of the observation and the moon was high in the western sky. Unfortunately the seeing was very poor and limited the detail that could be resolved during the observation. All in all a nice break from the very cold cloudy nights that defined January this year.


For this sketch I used: black Strathmore 400 Artagain paper 14”x 6.5”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-2) and contrast increased (+1) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian 6mm eyepieces 241x
Date: 2-1-2009; 0:00 - 2:15 UT
Temperature: 1° C (34° F)
clear, windy
Seeing: Antoniadi IV
Colongitude: 342.3 °
Lunation: 5.7 days
Libration in Latitude: -6° 3’
Libration in Longitude: -7° 8’
Illumination: 29.5 %

Frank McCabe :)

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#2 Tom and Beth

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Posted 01 February 2009 - 09:22 AM

I hope someday to be able to sketch that nice!

#3 JayinUT


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Posted 01 February 2009 - 09:48 AM

Frank, I feel like I'm looking at it through a scope! I have to say "ditto" to what Tom said.

#4 rodelaet



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Posted 01 February 2009 - 02:10 PM


It's a beautiful sketch. :bow: :bow: :bow:
The curvature of the moonscape together with the roughness of the craters reminds me of the hostile environment the moon was (and still is).

#5 frank5817



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Posted 01 February 2009 - 06:59 PM

Tom, Beth, Jay and Rony:

Thank you all for the kind words. The seeing was poor but I attempted to stay with it. Occasionally and briefly seeing would improvement but it was mostly a tease. It felt good to be sketching the moon outdoors again within tolerable weather conditions.

Frank :)

#6 CarlosEH


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Posted 01 February 2009 - 10:37 PM


An outstanding observation of the South Polar Region of the Moon. You have captured this complex region very nicely. Thank you for sharing it with us all.


#7 frank5817



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Posted 02 February 2009 - 11:52 AM


Thank you. :thanx: I always enjoy observing this region of the moon.

Frank :)

#8 Tom Machtemes

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Posted 02 February 2009 - 12:16 PM


Very good sketch :cool: I'm looking forward for your next.



#9 Tommy5



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Posted 02 February 2009 - 08:34 PM

Very nice sketch, the 1st quarter moon is riding very high,about where the sun will ride in the coming summer months, thanks for posting.

#10 frank5817



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Posted 03 February 2009 - 02:33 AM

Tom and T5,

Thank you both. Yes I was very surprised to see the moon tonight. I was expecting clouds and snow. I was thinking the same thing T5. The moon was in the summer sun position.

Frank :)

#11 markseibold


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Posted 03 February 2009 - 03:30 AM


Its always good to see your consistent close-ups. :bow: :bow: :bow: I was showing this very cusp of the terminator to others at a local restaurant where I set up the portable Nexstar 5i scope a couple nights ago.

Thanks again for reminding me to get out and concentrate on a close-up. I am overdue.


#12 Special Ed

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Posted 03 February 2009 - 11:17 AM

Nice job, Frank. :) I really like these limb areas.

Rony's impression of a hostile environment is fitting. Amundsen and Scott led separate expeditions across Antartica to the South Pole. Scott and his companions did not survive the ordeal.

#13 frank5817



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Posted 03 February 2009 - 12:47 PM

Mark and Michael,

Thank you for your nice comments. I wish the seeing had been a little better.
When we are having a cold winter in Chicago, I just can't imagine how explorers like Amundsen and Scott and others could hope to survive a trip to the South Pole and back.

Frank :)

#14 mickmrn1



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Posted 08 February 2009 - 09:18 PM

This looks great with a 6mm eyepiece! Very nice sketch indeed Frank!!

#15 Erix


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Posted 08 February 2009 - 10:53 PM

Very tough area to capture on paper, but you've certainly nailed it. Beautifully rendered, Frank!

#16 Uwe Pilz

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Posted 09 February 2009 - 02:07 AM


craters near the limb are very hard to sketch. You did the job very well. Thank you for sharing and to encourage me to do this more often.

#17 frank5817



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Posted 09 February 2009 - 07:55 PM

Michelle, Erika and Uwe,

Thank you. :thanx: Turns out I picked the wrong night to make this sketch. On the very next night just before packing it up I took a look at this region and the view was spectacular and the seeing was as good as it gets from here.

Frank :)

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