These are great, thanks Frank 🙂

Harbinger Mountains with Prinz & Kreiger

Harbinger Mountains with Prinz & Kreiger

Prinz, Kreiger, Harbinger Mountain Region

The kilometer high rim of Prinz (47 km.) crater was casting a shadow across its own lava flooded floor. The uplifted Harbinger mountains were also casting fine shadows in this region with its large magma ponds pushing up and freezing in the distant past. The uplifting doming in the region created many fissures for lava escape and flooding to occur. Several fissures could be seen clearly on this night of steady seeing conditions. From the crater Krieger (22 km.) north and somewhat east of Aristarchus (not in this sketch) four distinct long shadows could be seen crossing the edge of the Aristarchus plateau where the terminator was located during the rendering of this sketch. In addition to these features the following are included in the sketch: Angstrom (9.8 km.), Wollaston (10 km.), Artsimovich (9 km.), Van Biesbroeck (10 km.), Dorsa Argand and the Prinz rilles.


Sketching was somewhat challenging for me without my drive platform for the scope.




For this sketch I used: black Canson paper, white and black Conte’

pastel pencils and blending stumps, white Pearl eraser

Telescope: 16 inch f/ 4.4 Dobsonian and 9 mm eyepiece 199x

Date: 11-11-2016, 01:00 – 02:35 UT

Temperature: 22° C (72° F)


Seeing: Antoniadi I-II (very good)


Frank McCabe


Crater Gassendi

Crater Gassendi

Gassendi Crater,


Protruding inside the northern rim of the Mare Humorum is the large floor

fractured crater Gassendi. If you close your eyes and try to picture in your mind

a large lunar crater, the image may look something like Gassendi. The 114 km.

walled plain crater is shallow as a result of lava upwellings beneath the floor,

especially toward the east side where the highest concentrations of floor fractures are located

and crisscrossing.  The shallow south end is tipped facing the center of Mare Humorum.

The northern end of the crater floor is rubble strewn and hummocky. The eastern

floor sports ridges and small craters in addition to rilles which were clearly

visible in the good seeing of this night. The southern floor has an irregular

ridge that is parallel to the low rim. The large central peaks (1.2 km. high) and

several smaller ones were seen in good relief with sharp black shadows. The deep

crater Gassendi A (32 km.) on the north rim of the larger Gassendi contrasted nicely with

respect to depth.

Shallower and smaller Gassendi B (25 km.) is just north-north-west of A.  Mare

Humorum is estimated to be 3.9 billion years old and Gassendi perhaps 100 million

years younger. If Apollo 17 planners had chosen Gassendi as the last lunar landing

site we would likely know the ages more accurately today.





For this sketch I used: black Canson paper, 9”x12”, white and

black Conte’ pastel pencils and a blending stump and White pearl eraser.


Telescope: 16 inch f/ 4.4 Dobsonian 6mm eyepiece 298 x

Date: 11-11-2016 3:05-4:45 UT

Temperature: 18°C (66°F)

Clear, calm

Seeing:  Antoniadi II


Frank McCabe