Moon – Page 51 – Astronomy Sketch of the Day

Pardon My Hyperbole

Rima and Rupes Cauchy
By Rich Handy

Scanning the area to the west of the famous hyperbola shaped rille and rupes pair, I was pleasantly surprised to see each extending further in that direction (Rupes and Rima Cauchy become faint rilles) and passing by some of the most interesting pyroclastic deposits, lunar domes and cinder cones I’ve ever seen on the lunar surface. Each extend further in the eastern direction as well. Unfortunately I’d need two large sheets to sketch this area in the kind of detail it deserves, so I settled for this somewhat smaller vista. Check out Chuck Wood’s “The Modern Moon” page 88 and 89 for an excellent overview of this exciting area and Rukl Atlas Plates 36 and 37 for a detailed view of this amazing area. Rima Cauchy is just to the north of Cauchy, a 14 km, bowl shaped Copernican era crater that sits amidst the eastern Sea of Tranquility and pretty close to Sinus Concordiae, the mare area that tapers off to the north. To the south is Rupes Cauchy, its wall brightly lit in the the last rays of the late lunar afternoon. Immediately to the south of the Rupes were the two domes, Cauchy Tau to the west (right) and Cauchy Omega to the east. I noted the central peak on Omega with no problem, a testament to the kind of seeing I was blessed with last night. Though I couldn’t say with absolute certainty, there seemed to be two “Arago-like” domes below 12 km Eratosthenian aged Zahringer near the smaller 11 km Taruntius F.

Next time you are observing this area, take some time to visit this rare fault and rille and it’s terribly interesting environment. It may sound like hyperbola, but I’m not exaggerating, this place is lunie dreamland!

Here are the sketch details:

Subject: Rima and Rupes Cauchy and environs Rukl: 36,37
Date: 9-10/11-06 Started: 6:40 UT End: 8:24 UT
Seeing: Antoniadi I-II Weather: Clear most of session then fog late.
Telescope: 12″ Meade SCT F10
Binoviewer: W.O. Bino-P with 1.6X Nosepiece.
Eyepieces: W.O. WA 20mm Plossls
Magnification: 244X
Lunation: 18.48 days Phase: 311.1 deg Illumination: 82.9%
Colongitude: 133.7 deg Lib in Lat.: -3 deg 53 min Lib in Long.: +5 deg 12 min
Sketch medium: White and black Conte’ Crayons on black textured Strathmore paper.
Sketch size: 18″ x 24″

Raised, Tilted and polygonal

The Aristarchus Plateau
By Frank McCabe

The Aristarchus Plateau

The 3.6 billion year old Aristarchus plateau is a raised, tilted polygonal block
of crust in the ocean of storms with a collection of interesting features that can
be seen with telescopes of all sizes. Crater Aristarchus left of center is a large
(41 km.) 3.2 km. deep crater that is bright, young (500 million years old) and
sits near the SE edge of the plateau. Lunar Prospector spacecraft back in 1998-99
detected radon gas being released from this region. The Space Telescope Science
Institute along with Northwestern University and others conducted an ultraviolet
and visible light analysis using the Hubble telescope to detect the presence of
titanium oxide near crater Aristarchus. This could be a potential source of oxygen
on the lunar surface and also a source of titanium metal.
   I remember well my disappointment when Apollo 18, 19 and 20 were cancelled in
1970. Apollo 18 was scheduled to land on the Aristarchus plateau near Schroter
valley. Schroter valley is an old Imbrium (3.5 billion years old) volcanic
feature that begins at the famous cobra head 25 km. north of ancient crater
Herodotus. This feature meanders north then west then southwest for more than 150
km. The bend is nearly 170 degrees. It is also large enough to be seen in a 2
inch telescope under conditions of good seeing.
The region surrounding the beginning of Schroter valley was carefully imaged March
3rd and April 27th in 1994 by Clementine spacecraft because of reported color
changes. Clementine confirmed these changes were real. This region of the moon
shows color visible to some observers. It is described as reddish or yellowish by
those that can see this color.
Don’t think of the moon as an annoyance that spoils galaxy hunting as some deep
sky enthusiasts sometimes do, but embrace it as the beautiful satellite it is,
awaiting observation and exploration.


Sketch:
Graphite pencil, pen and ink sketch on copy paper 8.5”x11”
Date: 1-2-2007 1:50 to 3:45 UT
Temperature: -1.2 °C (30° F)
Calm, seeing good for this part of Illinois
Antoniadi mostly IV briefly III
13.1 inch f / 5.9 Dobsonian 6mm ortho ocular 327X
Colongitude: 66.8°
Lunation: 12.5 days
Illumination: 97%

The Strong Pair

Lunar Craters Atlas and Hercules
By Frank McCabe

Atlas and Hercules the well known crater pair in the northeastern corner of the moon
are not far to the southwest of Endymion. Atlas (87 km.) the largest of the
pair may also be the younger of the two although it is listed as Upper Imbrium
era. Hercules (69 km.) is considered to be Eratosthenian in formation and thus
both craters are older than three billion years. Based on a lower crater
(craterlet) count and the younger appearance of the glacis, the Hercules impactor
may have struck first, followed by a few small crater forming strikes and then the
Atlas forming impact. The floors of these two craters are quite different from
each other. Atlas has a floor the is centrally uplifted and fractured into deep
fissures and rilles (Rimae Atlas) from the uplifting magma below that was unable
to flood the floor in the way that occurred with Hercules. The floor of Hercules
is mostly flooded with dark lava and contains a 13 kilometer crater (G) near its
center. The hotel sized rock that struck here less than a billion years ago left a
bright crater with rays that can be seen at high sun. A ghostly crater designated
Atlas E (58 km.) was justvisible north of Atlas and smaller Keldysh (34 km.) to the
north of Atlas E

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 9”x 12”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
(-8) and contrast increased (+8) after scanning using Microsoft Office Picture
Manager.

Telescope: 10 inch f/5.7 Dobsonian and 6mm eyepiece 241x
Date: 2-14-2008 2:10-4:15 UT (actual sketching time was 50min.)
Temperature: -7°C (20°F)
partly cloudy, calm
Seeing: Antoniadi III
Co longitude: 358.6°
Lunation: 6.9 days
Illumination: 48.6 %
Phase: 91.6°

Frank McCabe

Of Blocky Origins

The Region of Vallis Rheita

Very early Sunday morning the moon was approaching the meridian about 35° above
the southeastern horizon when I decided to take a closer telescopic look and
select a sketching target. Prominently on display near the sunset terminator was
the famous 330 kilometer long Vallis Rheita. This valley formed as a by-product of
the secondary blocks thrown from the mare Nectarius basin forming event that
occurred 3.92 billion years ago. Apollo 16 astronauts John Young and Charles Duke
collected rock samples that included ejecta from the Nectarius event which
permitted the dating. A multitude of monstrous blocks heaved out from the initial
impact to the south created this less than regular catena. The valley lines up
nicely with the west central region of the Sea of Nectar accounting for this
hypothesis.
Adjacent to the northern end of Vallis Rheita and slightly younger in age is
crater Rheita, a 70 kilometer gouge with a low central peak and a fairly sharp
crest. Across the deep valley from Rheita to the southwest is 88 kilometer crater
Metius with its 4 kilometer high walls and small crater Rheita B east of a pair of
low ridges on the crater floor. This highland region of the moon is very old and
battered. It was showing some of its best features in the setting sun.


Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 8”x 10”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
(-5) and contrast increased (+5) after scanning using Microsoft Office Picture
Manager.

Telescope: 10 inch f/5.7 Dobsonian and 6mm eyepiece 241x
Date: 2-24-2008 0:10-1:00 UT
Temperature: -8°C (19°F)
clear, calm
Seeing: Antoniadi III
Co longitude: 123.2°
Lunation: 17 days
Illumination: 90.1 %
Phase: 323.3°

Frank McCabe

Majestic Copernicus Crater

Lunar Crater Copernicus
By Frank McCabe

Across the Carpathian Mountains resting on the eastern Ocean of Storms is the
landmark crater of the Sea of Islands, mighty Copernicus. Copernicus is a 95
kilometer diameter complex crater that begins to show itself in all its majesty
two days past first quarter. During the time of “Snow-ball Earth” 800 million
years ago the event that created Copernicus suddenly occurred. What remains is a
3.8 kilometer deep hummock covered flat floored, centrally peaked, terrace walled
spectacular sentinel. Especially during high sun the bright ray system of this
crater can be seen extending from the base of the glassy glacis in all directions.
The descent from the rampart to the mare floor below is about one kilometer. Three
of five peaks were clearly visible in morning sunlight. In 1999 the Clementine
near infrared camera detected magnesium iron silicates in the peaks indicating
rebound of this deep rock through the surface crust following the impact event.
To view this impressive crater all you need is a good pair of binoculars and an
opportunity between two days past first quarter and one day past last quarter.
Weather permitting you can see it tonight.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 9”x 12”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
and contrast increased after scanning using Microsoft Office Picture Manager.

Telescope: 10 inch f/5.7 Dobsonian and 6mm eyepiece 241x
Date: 2-16-2008 8:45 – 10:50 UT (actual sketching time was 60min.)
Temperature: -10°C (14°F)
clear, calm
Seeing: Antoniadi III
Co longitude: 24°
Lunation: 9 days
Illumination: 71.9 %
Phase: 64°

Frank McCabe

In the Last Rays of the Day

Lunar craters Aristoteles and Eudoxus
By Frank McCabe

Aristoteles and Eudoxus

Sketching:
For this sketch I used: black Strathmore 400 Artagain paper, white and black Conte’
pastel pencils and a blending stump. Brightness was slightly decreased after scanning.
Telescope: 10 inch f/ 5.7 Dobsonian and 6 and 4 mm eyepiece 241 and 362X
Date: 6-6-2007 9:05-10:00 UT
Temperature: 8° C (47° F)
Clear, calm
Seeing: Antoniadi II-III
Colongitude: 158.7 °
Lunation: 20.6 days
Illumination: 72.7 %
Frank McCabe

Shepard Courtier of Selene

Northeastern Lunar Limb Crater: Endymion
By Frank McCabe

Northeastern Lunar Limb Crater: Endymion

The lunar libration on this evening was not favorable for viewing Mare
Humboldtianum. However the 125 kilometer diameter dark floored crater Endymion was
well placed in lunar morning sunlight just 300 km. southwestward of the mare
center. I was keen on rendering this crater because I knew it to be large, ancient
and in possession of a remarkable rim and rampart. Crater Endymion is an ancient
nearly four billion year old Nectarian formation. The highest reaches of the
mountains on the rim and apron tower at 4600 meters above the dark lava flooded
floor. I was unable to see under the viewing conditions the ray streaks from
crater Thales (not visible in the drawing) that are best seen at high sun. The
notable terracing on the inner rim was in shadow but much of the broken crater
ramparts were clearly visible about the crater’s circumference. Craters Atlas and
Hercules were visible nearby very close to the sunrise terminator and if the
temperature would have been a couple of dozen degrees warmer I would have enjoyed observing and sketching them.

Conditions at the time of this observation were less than ideal with a brisk wind
out of the northwest and an air temperature of -19° C (-2° F). I stretched this
sketch out over two hours plus so I could take frequent finger thawing breaks. I
have observed under much colder conditions but I need to take off my gloves to
sketch.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 9”x 12”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
(-4) and contrast increased (+2) after scanning using Microsoft Office Picture
Manager.

Telescope: 10 inch f/5.7 Dobsonian and 9mm eyepiece 161x
Date: 2-10/11-2008 23:15-2:20 UT (sketching time was 45min.)
Temperature: -19°C (-2°F)
clear, breezy
Seeing: poor back and forth between Antoniadi III and IV
Co longitude: 322.1°
Lunation: 3.8 days
Illumination: 17.2 %
Phase: 131.1°

Alexander’s Waning Ray

Alexander’s Waning Ray
By Richard Handy

When the waning Moon brings long spires of deep shadows to the mountains and scarps that line the western shores of Mare Imbrium, the peaks of the Montes Caucasus become beacons of bright white light, radiant and dazzling in the last rays of late lunar afternoon sun. This arcuate, rugged range, a remnant of the multi-basin rings raised by the titantic Imbrium impact, reach a lofty 6000 meters in elevation above Mare Imbrium and Serenitatis today. The strait that separates the Caucasus and the Montes Apenninus is probably the result of the previous Serenitatis impact. The collision excavated a large section of crustal material at the eventual and almost tangental intersection of these two great lunar basins, so here no mountains nor hills were lifted high enough to survive the much later inundation by mare basalts. The dark parabola of shadowed Alexander is illuminated by a single, slim dagger of light. Was this ancient Pre-Imbrium 82 km crater the result of an oblique impact? The heavy fill of ejecta from the Imbrium or Serenitatis events and the remainders of its sparse and broken ramparts make interpretation difficult, still it’s general elliptical depression begs this question. Between the Montes Caucasus and the Montes Alpes to the northeast lies Cassini with it’s smooth appearing glacis. This Lower Imbrium crater almost looks to have impacted into a semi-liquid layer of basalt, so soft and thin is the appearance of it’s glacis. To the northeast of Cassini, The Montes Alpes, a great blocky wedge composed of lineated chunks of broken regolith, is scattered radially from the center of Imbrium, evidence of the sheer power of an explosion that lifted up mountain ranges and tossed aside blocks of lunar crust the size of stadiums hundreds of kilometers from it’s center. Beyond the field of view of this sketch, the Vallis Alpes confirms the readjustment that occcured millions of years after the Imbrium event, as large sections of crust pulled apart under the stresses of sublithospheric flows.

Sketch details:

Subject: Alexander’s Waning Ray Rukl: 12, 13,
Time: 9:50 UT to 10:17 UT Date: December 30, 2007
Seeing: Antoniadi III -IV Weather: clear and 10 mph breeze
Lunation: 20.68 days
Colongitude: 164.0 deg.
Illumination: 58.9%
Lib. in Lat.: +03 deg. 30 min.
Lib. in Long.: +06 deg. 29 min.
Phase: 280.2 deg.
Telescope: 12″ Meade SCT f/10
Binoviewer: W.O. Bino-P with 1.6X nosepiece
45 deg. W.O. erect image diagonal
Eyepieces: 18mm W.O. Plossls
Magnification: 271X
Sketch Medium: White and gray pastels on Strathmore black Artagain paper
Sketch size: 18″ X 24″

Petavius Yet Again

Evening and Morning Light on the Crater Petavius
By Frank McCabe

On the 6th day of March 2007, I sketched crater Petavius in the evening light
close to the time of sunset at Petavius. This large rather circular floor
fractured crater appeared elongated and ellipsoidal because of its proximity to
the limb and in a somewhat unfavorable libration. I was hoping on Wednesday
evening during the next lunation to catch the crater again just after sunrise but
I was thwarted by clouds and rain 16 days after the first drawing. However the
next evening had some breaks in the cloud cover before the rains reappeared and I
was able to sketch Petavius in the lunar morning sunlight and also at a more
favorable libration which explains its more circular appearance. Upon completion
of the second drawing I rotated and resized it using Microsoft paint and placed it
with the earlier sketch. Seeing the same features in the morning and evening light
adds to the endless enjoyment of lunar observing any time during a lunation or
between lunations as occurred here. The March 6th sketch (evening at the crater)
was posted at this site March 17, 2007. The March 23rd sketch (morning at the crater)
made 17 days later is posted second. I used the same telescope and eyepiece to
sketch both drawings.

Sketching: 1st Sketch
For this sketch I used: black Strathmore 400 Artagain paper, white and black Conte’
pastel pencils and a soft blending stump.
Telesccope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece
Date: 3-6-2007 2:45-3:30 UT
Temperature: -6°C (21°F)
Clear, calm
Seeing: Antoniadi IV
Colongitude 113.5°
Lunation 16.5 days
Illumination 95%


Sketching: 2nd Sketch
For this sketch I used: black Strathmore 400 Artagain paper, white and black Conte’
pastel pencils and a soft blending stump.
Telesccope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece
Date: 3-23-2007 1:10-2:20 UT
Temperature: 17°C (62°F)
Partly and at times mostly cloudy, variable winds
Seeing: Antoniadi III- IV
Colongitude 320°
Lunation 4 days
Illumination 22 %

Frank McCabe

Clearing the Confusion

Rosenberger and Vlacq near the Terminator
By Frank McCabe

This region of the moon is often called the confusing southeastern lunar highlands
for all the large and medium sized look-alike craters. This appearance continues
to the lunar far side as can be see in lunar orbiter photos. But looking again the
picture really changes dramatically at low sun. The two large craters I have
chosen for this sketch are both ancient (pre-Nectarian) and pre-date the early
basin formation on the moon. Rosenberger crater (96 km.) is the largest of the
pair to the left (east) in the drawing. This four billion year old crater has a
rim worn down to the level of the surrounding highlands by numerous crater impacts
and inner wall subsidence that has obliterated most of the wall terracing. It is
2.6 kilometers from the highest rim point to the mostly flat crater floor which in
the low sun was showing off its low central peak. A crater of 14 km. was about to
be consumed by shadow at the time of this sketch. This floor crater is Rosenberger
S. The other large crater to the southwest of Rosenberger is Vlacq, a crater of 89
kilometers and from all appearances perhaps the youngest of the pair. The twin
peaked central mountains and terraced walls give this crater a younger look. It
also appears from the bulging of the wall shared with its larger neighbor that the
body that struck the moon forming Vlacq came in second.
The observing and sketching was enhanced by steady seeing intervals that lasted
several minutes at a time.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 9”x 10”, white and
black Conte’pastel pencils and a blending stump. Brightness was slightly decreased
after scanning.

Telescope: 10 inch f/5.7 Dobsonian and 6mm eyepiece 241x
Date: 11-28-2007 5:30-7:00 UT
Temperature: -3°C (26°F)
partly cloudy, breezy
Seeing: back and forth between Antoniadi II and III
Co longitude: 135.2°
Lunation: 18.5 days
Illumination: 80.3 %