rille – Page 4 – 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%

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

Semiannual Lunar Ritual

Vallis Schröteri and environs
By Jeremy Perez

And so, in the spirit of completing one Lunar sketch and observation every 6 months or so, I present Vallis Schröteri. On the night I made this observation, I was very impressed by the rugged terrain in the vicinity of this sinuous rille. The whole area looked like a badly skinned knee in merciful shades of gray. Although Vallis Schröteri was the celebrity, a few other features played staring roles. Mons Herodotus shone brilliantly while the craters Herodotus and Aristarchus stared out like spectacled eyes with the teardrop of Väisälä glistening on the burnished cheek of a nearby highland. Further to the north, Montes Agricola embraced the region like the tip of a rattlesnake’s tail.

There was so much to observe and sketch, I couldn’t possibly capture it all. I did learn from my previous attempts at white on black Conté sketching and went for a larger illustration. This sketch was prepared on a 9″ x 12″ sheet of black Canson Mi Tientes pastel paper. I used a blending stump to smooth the pastel where appropriate and to build up brighter tones. The brightest rims are straight attacks with the Conté pencil. The sketch took about 45 minutes at the eyepiece with another 15 minutes of additional touch-up indoors. White on black sketching is really a great way to tackle the moon–especially the terminator. I hope to keep working at it when time permits. I’ll still be using pencil and charcoal, but it’s nice to have this method accessible when I want it.

Object Information:

Vallis Schröteri is the largest sinuous valley on the Moon. Although hidden in shadow in my sketch, this valley makes its start at a 6 km diameter crater just north of Herodotus crater and widens to 10 km. This area is sometimes referred to as the Cobra’s head. It then winds 160 km and narrows to 500 m at it’s end. The rille is likely the result of volcanic activity as a lava flow carved its winding path through the landscape. Aristarchus is a remarkably bright crater with a pronounced ray system. It is 40 km in diameter and is believed to be a relatively young 450 million years old.

Subject Vallis Schröteri and Surroundings
Classification Sinuous Valley, Craters and Mountains
Position West
Phase/Age 11.7 Days
Size* Vallis Schröteri: 160 km length x 1000 m depth (max)
Herodotus: 35 km dia
Aristarchus: 40 km dia x 3000 m depth
Väisälä: 8 km dia
Dorsum Niggli: 50 km length
Montes Agricola: 160 km length
Mons Herodotus: 5 km dia

Date/Time April 28, 2007, 10:00 PM MST (April 29, 2007, 05:00 UT)
Observing Loc. Flagstaff, AZ – Home
Instrument Orion SVP 6LT Reflector (150 mm dia./1200 mm F/L)
Eyepieces/Mag. 10 mm + 2X Barlow (240X)
Conditions Partly cloudy, calm
Seeing Ant. III
Sources Atlas of the Moon by Antonín Rükl 2004; Observing the Moon by Gerald North 2000.
* Based on published data.

Sunken Yet Uplifted

The lunar crater Posidonius
By Frank McCabe

Posidonius on the Eastern Shore of the Sea of Serenity

On this cold morning in early December the most eye-catching crater resting on the
concave sloping rim of Mare Serenitatis was 96 kilometer diameter Posidonius. The
Posidonius cratering event likely occurred 150 thousand years or more after
Serenitatis formed a ring basin. The subsequent floor uplift and fracturing within
Posidonius created a large angular block and ridge margin that you can see arching
parallel along and just inside the outer eastern crater rim. At 17.5 days into the
lunation, the floor of Posidonius appeared much brighter than the dark margin lava
of Serenity. Eleven kilometer crater A near the center of Posidinius was clearly
visible in the poor seeing as were craters B, J, and M arching out from the rim to
the north. Beyond these craters encircled by the Lake of Dreams is 25 by 30 km.
oval “island crater” Daniell, formed by a shallow angle impact before the greater
Posidonius event took place. South from Posidonius and again along the shore of
Serenity is the 63 km. flooded crater LeMonnier. Nearly all of the west rim of this
tilted crater and its floor are covered by the dark margin lava of the Sea of
Serenity.

Sketching:

2H graphite pencil on 5 x 8 inch index card
Date: 12-8-2006 11:30 to 12:15 UT
Temperature: -14 °C (6° F)
clear, cold winds
Pickering scale: 3/10
10 inch f / 5.7 Dobsonian 161X
Colongitude:127.5°
Lunation: 17.6 days
Illumination: 86.3 %

Frank McCabe

A Tranquil and Serene Tapestry

Mare Serenitatis and Mare Tranquillitatis
By Giorgio Bonacorsi

Hello, my name is Giorgio Bonacorsi, I live in little town named Pergola, in Marche, center Italy. My night sky is good, I live near mountain Catria(1702m). My observation site are at 3-4 minutes from home and are at 400-500 m of altitude. I go there for my sketches of galaxy and other object of deep sky,but also behind my home I have a good sky, principally for Moon, planets and comets. My instruments are: Newtonian telescope 15cm 750f, acromatic80/1000, maksutov-cassegrain 110/1035, 16×80 binocular.

Approaching Sunset at Posidonius Crater

On this night I watched the sunset terminator move slowly toward ring-plain crater
Posidonius while I sketched the crater and nearby features on the floor of 750 km.
diameter Mare Serenitatis. Posidonius (99km.) is an old upper Imbrian era impact
reminant. Its age is betrayed by the way shadows penetrate the rim at numerous
points as the sun continued to set. The highest part of the rim is on the
terminator side of this crater. Sunlight was still reaching part of Posidonius A
and two other high points on ridges including one on the inner ring. Beyond this
crater to the west and south the great serpentine ridge could be seen in best
light. This ridge is made up of dorsa Smirnov and dorsa Lister just north of
crater Plinius (44 km.). Smaller and younger crater Dawes (19km.) could be seen
casting a shadow eastward which was growing in length throughout the sketch
interval.

Sketching:

2H graphite pencil, black felt tip marker on white copy paper, gum eraser
Date: 12-10-2006 8:05 to 8:40 UT
10 inch f / 5.7 Dobsonian 9mm ortho ocular 161X
Temperature: 3°C (37° F)
Clear, calm
Antoniadi: III-IV
Colongitude: 150.1°
Lunation: 19.4 days
Illumination: 71.2 %

Frank McCabe

Janssen and Fabricius in the Lunar Southeast

Janssen at 195 kilometers in diameter is a large ancient (4 billion year old)
walled plain crater in the southeastern highlands and is not far from the lunar
limb. Relentless moonquakes and solar system debris impacts have given this crater
its old look. The floor of Janssen is covered by numerous smaller craters. Without
trying too hard I could see 20 crater including those down to a few kilometers in
diameter. The center of the crater appears to bulge higher than the worn rim. Much
of this could be debris from the large much younger impact crater Fabricius (79
km.). Fabricius is an Eratosthenian period impact crater. It clearly shows steep
sloping walls and exhibits a central mountain range that is about 11 km. long and
also a long central ridge that is more than twice that length. Geologists tell us
that much of the debris across the floor of Janssen is Nectaris impact ejecta;
fluidized where the floor is smooth and irregular boulder-like where the floor
appears tortured. But perhaps the most interesting feature here is 140 kilometer long Rimae
Janssen. This rille looking like a graben, where it cuts through the high central
region south of Fabricius. It then narrows suddenly before reaching the rim in the
relatively smooth region of the floor. Pits that are visible via high resolution
images in these narrow regions imply volcanism. There is at least one dome on the
floor of Janssen but I was not successful in spotting it in the current
illumination. Craters Janssen and Fabricius presented fascinating features to
examine during this observation.

Sketching:
For this sketch I used: black Strathmore 400 Artagain paper, 7”x11”, 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: 9-29-2007 6:15-7:15 UT
Temperature: 16°C (60°F)
Clear, calm
Seeing: Antoniadi III
Co longitude: 122.1°
Lunation: 17.73 days
Illumination: 91.4 %

Frank McCabe

A Lunar Favorite

Gassendi Crater, a Lunar Favorite

Protruding inside the northern rim of the sea of moisture 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 upwelling across the floor
especially toward the east where the highest concentrations of floor fractures are
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 the evening. The southern floor has an irregular
ridge that is parallel to the low rim. The large central peaks (1.2km. high) and
several smaller ones were seen in good relief with sharp black shadows. The deep
crater Gassendi A on the north rim of the larger Gassendi contrasted nicely with
respect to depth.
Shallower and smaller Gassendi B was just north-north-west of A. The rough
highlands around Rimae Mersenius were visible to the west of these three craters
and low hills in the Herigonius region could be seen to the east of Gassendi. 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 today.


Sketching

For this sketch I used: black Strathmore 400 Artagain paper, 9”x12”, white and
black Conte’ pastel pencils and a blending stump. Brightness was slightly
decreased after scanning.

Telescope: 10 inch f/ 5.7 Dobsonian 6mm eyepiece 241x
Date: 9-23-2007 2:05-3:15 UT
Temperature: 17°C (62°F)
Clear, calm
Seeing: Antoniadi II
Co longitude: 47.5°
Lunation: 11.6 days
Illumination: 82.7 %

Frank McCabe

A Birthday Tribute

On August 5th 1971 the Astronauts of Apollo 15, David Scott, James Irwin, and
Alfred Worden were coming home. It was the 11th day of the mission, and the 2nd day
of their voyage back to Earth after a successful mission to the lunar surface.

Six days earlier on July 30th, Apollo 15 Commander David Scott and Lunar Module
(LM) pilot James Irwin had landed in the Rima Hadley/Montes Apenninus region of the
Moon in the Lunar Module Falcon. “OK, Houston. The Falcon is on the Plain at
Hadley.”, said David Scott upon touchdown. The Command and Service Module (CSM)
pilot, Alfred Worden continued in lunar orbit in the CSM Endeavour and conducted
scientific experiments. While on the lunar surface, Scott and Irwin made three
moonwalk Extra Vehicular Activities (EVAs), becoming the 7th and 8th men to walk on
the Moon. During the EVAs which totalled 18 hours, 35 minutes, they covered 27.9
km, and collected 76.8 kg of rock and soil samples. They also took photographs, set
up the Apollo Lunar Surface Experiments Package (ALSEP), and performed other
scientific experiments. This time the Astronauts didn’t just walk on the Moon, for
this was the first mission to employ the Lunar Roving Vehicle. Scott and Irwin used
the Rover to
explore regions within 5 km of the LM landing site. After the final EVA, David
Scott performed a televised demonstration of a hammer and feather falling at the
same rate in the lunar vacuum.

The LM lifted off from the Moon on August 2nd after 66 hours, 55 minutes on the
lunar surface. Once the Falcon docked with Endeavor, the lunar samples and other
equipment were transferred from the LM and it was jettisoned after a one orbit
delay.

The LM Falcon impacted the Moon on August 3rd, 93 km west of the Apollo 15 ALSEP
site. It had an estimated impact velocity of 1.7 km per second.

On August 4th, after Apollo 15 underwent an orbit-shaping maneuver, a scientific
subsatellite was spring-launched from the Scientific Instrument Module (SIM) bay
into lunar orbit. The Apollo 15 crew began the transearth injection on the next
orbit which started their long journey home.

The next day, August 5th, Alfred Worden stepped into the black vacuum 196,000 miles
from the earth to become the first man ever to take a floating excursion outside
his craft in interplanetary space. The Apollo 15 astronauts, in prearranged
collaboration with Soviet and Dutch astronomers, were trying to observe what some
scientists suspect are “black holes” in the sky.

Meanwhile, back on Earth, Niel Armstrong was celebrating his 41st birthday. In
Houston not too far from Mission Control, Credence Clearwater Revival was jamming
at the Coliseum . Across the Atlantic Ocean in Munich Germany, An American Soldier
and his wife (Justin and Janet Aldridge) were celebrating the birth of their first
child. They named him Jason.

Two days later on August 7th, the Apollo 15 Astronauts splashed down in the Pacific
Ocean, 330 miles north of Honolulu, Hawaii and 6.1 mi from the recovery ship USS
Okinawa. 16 months later, Apollo 17 Commander Eugene Cernan would be the last man
to walk on the Moon.

A child of Apollo, Jason would grow up with dreams of traveling to the Moon. He saw
the color photographs of Mars that returned from the Viking Missions, and he knew
that someday he would visit Mars as well. He watched as the Voyager spacecraft flew
past Jupiter, Saturn, Uranus, and Neptune, and he knew that Man would explore the
solar system and beyond in his lifetime.

Today I am 36 years old. The dreams I had as a child are all but a fond memory now.
No Human has been back to the Moon, and there have been no manned missions beyond
Earths orbit. NASA plans to return to the Moon by 2018, almost 50 years after Niel
Armstrong first set foot there. I think my feelings about this matter are best
described in the words of Apollo 15 Commander, David R Scott:

“As I stand out here in the wonders of the unknown at Hadley, I sort of realize
there’s a fundamental truth to our nature, Man must explore . . . and this is
exploration at its greatest.”

I would like to dedicate this lunar sketch to the brave men of Apollo 15, David R
Scott, James B Irwin, and Alfred M Worden. I am honored to have been born during
their historic mission.

Jason Aldridge

PS: Happy Birthday Niel Armstrong!

*Sources: NASA NSSDC Master Catalog Display: Spacecraft, Apollo Flight Journal, New
York Times articles from 8/6/1971, Credance Clearwater Revival official web site.

Sketching Materials: 0.5mm Mechanical Graphite Pencil, Strathmore Windpower Sketch
Paper, MGI Photosuite III software for post processing.