crater – Page 49 – Astronomy Sketch of the Day

Between the ears of the rabbit

Craters Gutenberg and Goclenius

In the mid 1600’s Johannes Hevelius named this highland region east of the Sea
of Fertility Colchis (Land of the Golden Fleece) within a few years Giovanni
Riccioli named the same region Terra Manna. Two hundred years later both of
these names disappeared as the craters of the region continued to be named.
This lunar surface being erased by the shadow of the terminator early this morning
is between the ears of “The Rabbit in the Moon”. The largest crater with an
illuminated floor is battered Gutenberg, a 4 billion year old 75 km diameter
formation with a large breaching impact crater (Gutenberg E) on its northeastern
rim. East of the crater the widest and deepest part of Rimae Goclenius was glimpsed
as the seeing periodically improved. Domes in this area could not be seen with
certainty due to poor seeing. Southeast of Gutenberg crater Goclenius a 56 km
Nectarian age crater appears round with a floor in complete darkness. Also close to
the terminator are craters Magelhaens through Colombo.

Sketching:
For this sketch I used: black Strathmore 400 Artagain paper, white and black Conte’
pastel pencils and a blending stump.
Telesccope:10 inch f/ 5.7 Dobsonian and 9 mm eyepiece (161x)
Date: 4-6-2007 7:08-8:20 UT
Temperature: -1.6°C (29°F)
Partly cloudy, breezy
Seeing: Antoniadi IV
Colongitude 133.2 °
Lunation 18.2 days
Illumination 89 %

Frank McCabe

A photogenic pair

Theophilus and Cyrillus at Sunrise

Sketched over a 1.5 hour period at the eyepiece on Sunday April 22,
2007. (2:30 to 4:00 UT 23/04/2007) More time spent afterwards
colouring in shadow regions etc. Done with graphite pencils (4H to
4B), black ink and whiteout on white paper. Scope was Celestron
9.25, binoviewer, 2x barlow, and 24mm eyepieces. Picture was
reversed left to right once scanned to give a upright and correct
left/right view.

At the public star party last month (March) with the moon at the same
phase, I used a similar scope setup trained on these same craters to
illicit some “oohs” and “wows” from the crowd.   After spending most of
the time looking at these craters I realized that the pair was quite
‘photogenic’ and would make for a nice sketch.    This month, they were
even more strategically placed to reveal the terrain. The smaller
crater Madler was also quite interesting and included.    One thing that
made this sketch a bit out of the ordinary was the unusual interior to
Cyrillus which has some unusual landscapes near the border with
Theophilus. The light and shadows between Theophilus and the terminator
was also unusual and complicated. My first sketch in over a year; it
seems I’m slowing up. Taking this much time to capture all the details
is not the best for accuracy on transient lighting on lunar features.

Gerry Smerchanski

On the edge of a fertile sea

Langrenus at the Edge of the Sea of Fertility

With the Harvest moon just past and the shadow of the setting sun approaching the eastern shore of the Sea of Fertility, crater Langrenus stands out in all its glory. Langrenus is an Eratosthenian Period crater, between one and three billion years old. This crater is about 133 km. in diameter with a rim 2.6 km. above the bright, mostly flat floor. Mountain peaks near the center stand 1 km. high. Rays from the crater can be seen projecting in a westward direction across the Sea of Fertility. Much older (four billion plus years) and slightly larger than Langrenus to the south along the terminator is the crater basin Vendelinus. The walls of this crater were dealt crushing blows delivered by the impacts that created craters Lohse, Lame and Holden which are drawn clockwise from north to south. Many additional smaller crater impacts on Vendelinus attest to the age of this old battered basin.

More than 400 km. to the northwest, grazing angle impaction created the craters Messier and Messier A. These craters exhibit a long pair of rays extending westward across the remainder of the mare. Note the perpendicular (north-south) rays centered on Messier. Laboratory experiments have demonstrated this pattern of so called “butterfly rays” can be duplicated with shallow angle high speed impacts.

Frank McCabe

Sketching:
For this sketch I used: white copy paper 6”x 8”, and a 2HB graphite pencil
at the eyepiece with the addition of marker ink to darken shadows indoors.

Telesccope: 10 inch f/ 5.7 Dobsonian and 9mm eyepiece
Date: 10-9-2006 5:00-5:45 UT
Temperature: 10°C (50°F)
Clear
Seeing: Pickering 5
Co longitude: 114 °
Sunset longitude: 66.1° E.
Lunation: 16.8 days
Illumination: 94%

Lunar luminaries

2006 07 07

Lansberg/Gamma and Delta

“Wednesday night (Thursday for UT), was a practice session for imaging with my
Rebel. I finally bought a t-ring adaptor during a star party a few weeks ago and
had some fun playing with the new toy. The guys in the DSLR forum are giving me some
great pointers. Feels very strange entering that realm, but I have a feeling it
will compliment the sketching well for my observations. Plus gives me yet another
way to enjoy this hobby to the fullest!

It was then time to put the camera away and dig out my sketch kit. Paul, being the
thoughtful husband that he is, bought Tom L’s binoviewers for me last month. Tom,
if you’re reading this, I absolutely LOVE them! Wow! Thank you both so much!!!
I’ve been having a lot of fun with black Strathmore paper and Conte’ crayons for my
solar work, so with Rich in mind, I got up the nerve to try my first lunar sketch
with this media. Lansberg and the surrounding craters were my main targets that
night. I explored the terminator, tried to count craterlets in Plato, and admired
Copernicus (and was tempted to try it again, as the last time I tried to sketch that
beauty, my sketch was cut short and it was never completed).

Lansberg is from the Imbrian period and is about 41km. The central mountains stuck
out like two eyeballs in a dark room and I was pleased to see some terracing. All
the little craterlets around Lansberg belong to it with Kunowsky D being the
exception to the NW. Reinhold is trying to slip into the scene to the NE, but got
its toe stuck in the door. Montes Riphaeus was very dramatic, or at least compared
to the rest of the scene in that area.

After a great day today, which included solar observing (boy, that sun feels
great!), I set up with the binoviewers again tonight. Although seeing was poor, I
went ahead and bumped up magnification with 8mm TV Plossls (love that EP so much, I
had to get another one!). It was good enough to support the level of detail needed
to observe domes. Had I wanted to jump into a few complex craters, I believe a 20mm
would have been best. So, domes it was and why not a pair? Mons Gruithuisen Delta
and Gamma were flagging me down and I just could not resist.

They are also from the Imbrian period and close to 20km each. Looking at VMA, Delta
is classified as a mountain and Gamma is a dome. Rukl calls both of them a domelike
mountain massif. Hmmm, let’s see what Chuck Woods has to say about them. Aha! He
calls them domes, most likely formed of silicic volcanic rocks. For more reading on
this, see The Modern Moon, page 37. I would love to be one of the geologists that
Chuck suggests may someday bang on the domes with their rock hammers to see what
they are made of.
It was a bit disappointing that I didn’t see the summit crater on Gamma, but there
was an obvious darkened area on the western top portion of it. I loved buzzing
around in the all the little dips and valleys to the north of it, though. The
little raised line between Gamma and Gruithuisen K looked like a pea pod. Isn’t the
lava covered floor beautiful in that region?”
Sketches done with black Strathmore Artagain paper and white Conte’ crayons

Erika Rix

Zanesville, Ohio

Between Serenity and Tranquility

Craters Plinius and Dawes

After more than 23 days of very cold, cloudy, winter weather an approaching warm front got me out under the moon and stars on this clear, transparent night of good seeing. I centered the telescope field of view on craters Plinius and Dawes near the lunar terminator. This is the region I selected for my sketching. Plinius is the largest (43km) crater in the sketch. Its central peak and irregular, cratered floor are hidden in darkness but a hint of its terraced walls can be seen on the illuminated inner west margin. Further to the west the peaks near Promontorium Archeruia are catching the rising sunrays. About 55 km to the south of Plinius is crater Ross, a 26 km diameter crater identified only by its sunlit rim. This crater rests in the Sea of Tranquility. To the northeast of Plinius near the edge of the Sea of Serenity is the 19 km crater Dawes, its floor mostly in shadow. Directly to the north of Plinius the rilles of Plinius were clearly visible. In addition a small part of Dorsum Nicol is also seen. All of these features are positioned on the dark colored lavas at the boundary between the two above mentioned seas. The grazing sunlight helped to enhance the changes in topography.

Frank McCabe

Sketch details:
For this sketch I used: black Strathmore 400 Artagain paper 9”x12”, white and
black Conte’ pastel pencils and a soft leather blending stump.
Telescope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece
Date: 2-23-2007 1:05-1:45 UT
Temperature: 0C ( 32F)
Clear, calm
Seeing: Antoniadi II
Colongitude 339 degrees
Lunation 5.4 days
Illumination 35.7%

Entrance to a frozen Hell

There was a very thick mist that night, and the moon was hardly visible behind the clouds. I put the scope outside with no intent for observing, as I wanted to adjust a new home made focuser. It was a very pleasing surprise to discover that there was absolutely no turbulence at all on the Moon.
Despite the thick clouds, the light and contrasts were still strong, and everything was frozen, no movement at all. I jumped on my pencils, and made a draft of Eratosthenes, one of my favorite craters on the Moon, maybe my favorite. I like the long and thin design of the Apennine mountains terminating like a lyra, with that black and strange hole, just at the limit of infinite darkness.

Pierre Desvaux

– Medium used: White Conté on black Canson paper
– Telescope: Home made 16″ Dobson, Nagler 12, barlow 2X Celestron
– Date: December 2006
– Place: Blanzy, Bourgogne, France

Pacific places amidst “magnificent desolation”

Distinctive crater Stofler resides in the midst of the dense and chaotic crater field of the southern hemisphere of the Moon. One clear but very chilly evening in January 2007, the challenge of trying to capture the view was more than I could resist – this is my attempt. The sketch was carried out using white and black Conte’ pencils and chalk pastels on black ‘Canford’ paper. I began by marking out the main crater shapes using white Conte’ pencil, then I used a small chunk of white chalk pastel, broadside, to lay down the mare regions, blending this with a fingertip and a small cloth. More highlights were added (white Conte’ pencil), and a putty eraser used to define some of the features (and shadow extent) by negative drawing where I removed areas of pastel previously laid down. More detail was added with white Conte’ pencil as I went along, but there really was far too much to capture and I realized that I would have to quit while I was ahead and finish my outside drawing time before the view changed substantially. Once back inside I tidied up the sketch, removing the inevitable unwanted pastel smudges with a putty eraser, and re-defining some of the darkened inner crater edges with black Conte’ pencil, then using blending stumps (with touches of both white and black chalk pastel) to make final tiny adjustments. The sketch has been inverted and rotated in paint shop pro to give the standard orientation.

Sally Russell

Date: 25 January 2007

Time: 21.10-22.00 UT

Equipment: 105mm AstroPhysics APO/bino-viewer (mag x60)

Lunation: 7.3 days, 48.7% illumination

Sketch size: 6″ x 8″

The southern highlands of the Moon are almost completely dominated by craters in the 20 to 100 km size range, randomly scattered about the region. One way to determine relative ages of craters is to note which overlay or superpose over other craters or features, and the crater that obliterates or partially modifies another crater is usually younger. It is this principle that is the foundation of a stratigraphic approach to understanding lunar geological history. In the lunar highlands there is no shortage of overlapping or partially modified craters, and as Sally points out this region is about as densely chaotic as any on the Moon. A careful look at her beautiful sketch also reveals one of the great unsolved mysteries of the Moon. Many craters have smooth flat floors and the adjacent surface topography between these craters is also relatively smooth. The big question is: what is responsible for these smooth areas? Do the smooth floors and intercrater terrane reflect episodes of highland volcanism? Or perhaps these areas are covered with thick layers of ejecta that settled out across the surface as a result of this large scale stochastical gardening.

The shepard philosopher

When I looked outside that Sunday evening there was not a cloud in the sky and the eight day moon was shining down on me from a very favourable angle. There were far too many desirable sketches available, and my eyes darted from Rupes Recta toward the south, to Eratosthens and the shadows and highlands spinning off it, and further north to Plato sitting on the darkness of the terminator. It was a difficult choice, but I settled on Plato just because it had slightly more interesting shadows and also some very bright highlights emerging from the darkness near its northern rim. A long thin pointed shadow poured from the base of Mons Pico toward the terminator and also from another high area to its right as I viewed it. These shadows lengthening in the hour it took to do this sketch. Just above Mons Pico as I viewed (south is up) a change in the lunar surface was apparent in the form of an Eiffel tower shaped greyness which swept up to and finished at Piazzi Smith. Mons Piton sits with Piazzi in area across from Montes Alpes which had several sun kissed high points. I observed the needle like Vallis Alpes cutting a sharp gash in the surface through rugged lunar land, lit slightly on its northern edge. Feathery shadows set of the shape of Plato and detached from its northern rim, very bright high areas warmed themselves as they became uncloaked from the blackness.

Deirdre Kelleghan
President
Irish Astronomical Society 1937 – 2007

Sketch details:

February 25th 2007
20:45UT – 21:45UT
53.2000ºN, 6.1000º W
200mm/F6/6.3mm Plossel/193X
8.19 days
Seeing 2
Trans Average
300gm Daler R paper/DR soft pastels/Black watercolour pencil/wooden toothpick
www.irishastrosoc.org

Plato and Sheep

Nestled on the plains between Mare Imbrium and Mare Frigoris lies the nearly lava filled crater Plato. This 100 km, dark pool of frozen lava has a darker tone than the lava that filled the Imbrium basin. Crater counts indicate that the lavas that filled Plato are actually younger than the Mare lavas of Imbrium. The history of emplacement goes something like this: the Imbrium basin was created first, followed by the impact that created Plato, and then the gradual fill in of basaltic lava that flooded Imbrium and much of the existing basin rings and superposed craters. This left untouched some of the isolated massifs that are now known as Plato’s Sheep, including the towering Montes Pico (2500 meters high), Piton (2000 meters high), and the Tenneriffe Mountains (2500 meters high). Finally came the slow lava inundation of Plato itself. Above Plato and rendered with wonderful precision is the Vallis Alpes, a large graben (extension) fault which probably formed as a result of the original impact that created Imbrium. Dee’s beautiful sketch clearly depicts the drama that awaits the observer when the telescope is turned to this region as the terminator passes through.

Famously floor fractured

$Famously floor fractured$

Lunar crater Petavius

The end of winter in the Midwest can sometimes produce cold, clear, wind free nights. On this particular night the waning gibbous Moon cleared the tall barren trees where I had set up my 10″ scope to observe and sketch. After examining the Moon awhile at low power I selected a target close to the terminator for sketching. Near the edge of the southeastern corner of the Sea of Fertility is the large ancient crater Petavius. Connected by a rampart to the west (just right of Petavius) is 57 km Wrottesley. To the east of Petavius buried deep in shadow is the Palitzsch Valley, asequence of overlapping craters that extends for nearly 112 km. The atmosphere was in such turmoil that much of the subtle detail was obscured at the time of this observation. The multiple mountain peaks on the floor of Petavius stood out as did the terraced walls and the 60 km long straight rille from the central peaks to the southwest rim. Even under conditions of poor seeing this is a rewarding crater to observe a couple of days past full Moon. If you missed it, try again 3 days past New Moon. From March to the end of spring the waxing crescent Moon is a great target in the Northern Hemisphere.

Frank McCabe

Sketch data:

For this sketch I used black Strathmore 400 Artagain paper 9″ x 12″, white and black Conte’ pastel pencils and a soft blending stump.

Telescope: 10 inch f/5.7 dobsonian and 6mm eyepiece

Date: 3-6-2007 2:45-3:30UT

Temperature: -6C (21 F) Clear Calm

Seeing: Antoniadi IV

Colongitude: 113.5 degrees

Lunation: 16.5 Days

Illumination: 95%