Category: Moon

A Scarp, a Wall or a Sword

2010 10 16, 2351 UT – 2010 10 17, 0142 UT Rupes Recta
PCW Memorial Observatory, OH, USA, Erika Rix
Zhumell 16”, 20mm TV, 3x Barlow, 270x mag, 13% T moon filter
Temp: 7°C, 59% humidity, S: Antoniadi II, T: 2.5/6
Sketch created scopeside with Rite in the Rain paper and charcoal.

Phase: 65.2°
Lunation: 9.33d
Illumination: 70.9%
Lib. Lat: -3°50’
Lib. Long: +2°56’
Az: 209°37’, Alt: 32°06’

Rupes Recta: Scarp, 7.7° W, 22°S
Imbrian period (-3.8 billion yrs to –3.2 billion yrs)
Length: ~110 km, Height: 240-300 m, Apparent Width: 2.5 km

Located in Mare Nubium, this scarp, also known as the Straight Wall, was
apparent by the shadow cast from illumination from the east. The shadow
wasn’t very wide, but rather narrow and smudging to the west. The
eastern side of it was crisp and sharp. During the waning phase, this
same feature would appear as a white line from the illumination coming
from the west. The slope incline is ~30-40° (ref. Virtual Moon Atlas).
For a good comparison between the waning and waxing phases for this
feature, please have a look at this site:
http://www.astrosurf.com/lunascan/Rupesr.htm

Lightened areas around Birt (Copernician period) made a path from the
crater to the fault, showing off Birt A as well as a “V” shaped area
nestled between Birt and the companion craters K, J, and H (you will
have to look at an atlas for those craters as I wasn’t able to see them
during my observation last night).

The ridges to the south of Rupes Recta formed what I always pictured as
a scoop, make the ridge and the fault look like a ladle. Funny that a
woman should think of it a ladle whereas 17th century selenographer
Christiaan Huygens reckoned it looked more like a sword (ref. Modern
Moon, page 147). A lightened area to the south (top of the scarp in my
sketch from last night) outlined the circular ridge of Thebit S. It’s a
pity it wasn’t more defined during my observation. What I found very
interesting to observe was the darkened cirlce that Rupes Recta and the
wrinkle ridges to the west formed. I believe the ridges to the east
outline the ancient crater that Chuck Wood dubbed Ancient Thebit in the
Modern Moon.

Rima Birt looked more like a thin shadow than a rille. Looking back to a
sketch I rendered in 2005 using an LX200 Classic, not only was this
rille visible, but I also caught Birt E, which I didn’t see during last
night’s observation.

Resources
Rukl plate: 54 Birt
“The Modern Moon” by C. Wood pg. 146-147
Lunar Orbiter:
http://www.lpi.usra.edu/resources/lunar_orbiter/bin/info.shtml?300

Best regards,
Erika Rix
www.pcwobservatory.com

Cavendish Crater

Object Name: Cavendish
Object Type: Lunar crater
Location: Orleans, Ontario, Canada
Date of Sketch: Sept 20, 2010, 2250 EDT
Media: Graphite on white bond paper

This sketch was done at the eyepiece using a 127 mm Mak-Cas with a focal length of 1500mm and a 6mm EP on a night of very good seeing and transparency. I was struck by the crater on the southern rim of the crater Cavendish.

Gordon A. Webster

Progressive Moon

Object Name: Moon
Object Type: moon
Location: São Bernardo do Campo – SP – Brazil
Date: (5 nights – 2010)
Media: 0.5mm mechanical pencil on white paper
Instrument: binoculars Celestron UpClose 10×50 Wide Angle (7º)

Additional information:
The millions of lights from a huge metropolis (more than 20 million people) added to the heavy pollution do affect the sky observation. However, I found out an astonishing Moon through my binoculars, and whenever the sky was clear, I sketched it. I’ve done it from my apartment, fourth floor, through the window. The purpose was to register the position of the terminator, and how some features (specially the seas and Tyco crater) change their appearance according to the incidence of the sunlight. In this sketch we can also notice that there’s no “dark side of the moon”, in fact there’s a “hidden side of the moon”.
I can barely wait for my next vacations in order to go to Itajobi, on countryside, to keep observing under dark skies.
Clear skies to all.

Rodrigo Pasiani Costa

Waning Moon High in the East

Waning Moon High in the East

On the night of September 27-28, 2010, I witnessed the rising gibbous moon paired with the Pleiades near the northeastern horizon. By placing my thumb over the moon the seven sisters were clearly visible further to the north. Together they began their march across the sky after 9pm local time.
After I finished some indoor chores I returned to the telescope and set up to do some sketching.
Initially I considered sketching both of them together but soon changed my mind to go after just the moon. I spend about two hours recording as much as I could see before fatigue began forcing me to erase with greater frequency. This is my lunar sketching result.

Sketching:

For this sketch I used black sketching paper 9″ x 12″, white and black Conte’ pastel pencils, blending stumps, a gum eraser and brush. Brightness was slightly increased (+1) using the scanner

Scope 4.25″ f/5 Newtonian scope at 45x

Date: 9-28-2010, 1:00-3:00 local time
Temperature: 14° C (58° F)
clear, calm
Seeing: Antoniadi III
Colongitude: 151.6 °
Lunation: 20 days
Illumination: 78.3% Waning Gibbous

Frank McCabe

Ruined But Not Gone

It’s good to have dark skies returning again here in the North and a new season to look forward to.

I’ve always admired survivors, and on the moon Janssen has to count as one of the best; like a old warship that has taken hit after hit but refuses to sink. It’s classed as Pre-Nectarian, along with Brenner to its North, making it as old as solar system craters get. Metius, Lockyer and Steinheil however are later (Nectarian), and Fabricius later still (Eratosthenian). As well as the fun of picking out the subtle shadows of the rim of Jansen, there’s a curved (branched) rille to trace cutting its floor, which is one of the only highland rilles. Fabricius has two parallel mountain ridges on its floor. One can’t but wonder at the powerful forces that shaped this part of the moon billions of years ago.

Date and Location: 27th August 2010, York, UK; 21.30-22.30 UT.

Medium: Graphite pencil on white paper, sketched at the eyepiece.

Instrument: Skywatcher skyliner 152mm f8 Dobsonian, 10mmm ep with x2 Barlow.

Artist: Peter Mayhew

Waning Crescent Moon in Early Twilight

Waning Crescent Moon in Early Twilight

I was up early on this morning getting a look at some of the winter stars and witnessed a beautiful 25 day old waning moon. The earthshine was poor but after a look through a small Newtonian scope I decided to make a quick 40 minute sketch. It was a fine view.

Sketching:
For this sketch I used black construction paper 9″ x 12″, white and black Conte’ pastel pencils, blending stumps, a gum eraser and brush. Brightness was slightly increased (+1) using the scanner

Scope 2.5” f/10 Newtonian scope at 25x

Date: 9-4-2010, 10:00-10:40 UT
Temperature: 16° C (60° F)
clear, calm
Seeing: Antoniadi III
Colongitude: 220.2 °
Lunation: 25.3 days
Illumination: 22.1% Waning Crescent

Frank McCabe

A Collapsed Lava Tube

2010 08 29, 0820 UT Rima Hyginus
PCW Memorial Observatory, OH, USA, Erika Rix
Zhumell 16”, 20mm TV, 5x Barlow, 450x mag, 13% T moon filter
Temp: 12.8C, >90% humidity, S: Antoniadi I
Sketch created scopeside with Rite in the Rain paper and charcoal.

Phase: 307.3°
Lunation: 19.38d
Illumination: 80.3%
Lib. Lat: -6°04’
Lib. Long: -6°03’
Az: 260°08’, Alt: 34°57’

Rima Hyginus: Linear Rille, 7° E, 7.5° N
Imbrian period (-3.8 billion yrs to –3.2 billion yrs)
Dimension: ~226 km, Height: unknown
Named after Caius Julius Hyginus, 2nd century BC Greek Astronomer

http://www.lpod.org/archive/archive/2004/02/LPOD-2004-02-25.htm
“The key to understanding the origin of Hyginus is probably the small
pit craters visible in the rille on the northwest (left) side of
Hyginus. These pits almost certainly formed by collapse of the roof over
a lava tube.”

A lot of the features were washed out surrounding the rille, but the
flat floor of Hyginus was evident as well as its irregular shape. I
could make out some of the pits to the northwest half of the rille and a
couple hints of the craterlets (or pits) to the southeast half. The
subtle variances in albedo were difficult to render, however,
interesting to observe. If I remember correctly, the dark patch to the
north of H consists of volcanic ash.

While searching for information on this rille, I came across yet another
amazing image from Wes Higgins. The pits Chuck Wood wrote about in the
article above are clearly shown.
http://www.higginsandsons.com/astro/Pictures-iin-templets/Rima-Hyginus-08-03-07.htm

Resources
Rukl plate 34
“The Modern Moon” by C. Wood pgs. 58-59
LPOD:
http://www.lpod.org/coppermine/thumbnails.php?album=search&type=full&search=rima+hyginus

Erika Rix