A Monotone Scoop of Neopolitan Ice Cream

Schickard and Lehmann

Lunar craters Schickard and Lehmann
Sketch and Details by Jeremy Perez

It’s hard to get used to the fact that the moon plays misery on DSO observations two weeks out of every month. I can see that my biggest interest leans toward those dim patchy things, but given a little time exploring the moon, it still turns out to be very rewarding. So I took some time this bright moonlit evening to explore some likely craters listed in the Astronomical League’s Lunar 100.

Schickard is a large crater on the western limb of the almost full moon. There is an intersecting crater on the north end that looks about 20% as big.The southwest floor has a series of ridges or cracks that run northwest to southeast. There is also a half-circle of craters on the western floor. On the east side floor, a distinct white patch is visible.

After getting past the dazzling array of contrasting crater-wall shadows, I noticed to my surprise that the floor of the crater gave the appearance of a monotone scoop of Neopolitan ice cream. The north half and southeast tenth of the crater floor were darker than the rest of the floor. These three distinct shaded areas didn’t owe their differences to some lucky angle of light, as their boundaries ran roughly parallel to the angle of the sun. Also very noticeable was a rough jumble of terrain outside the crater along the west-southwest rim. It was tough to sketch that and make it look like it belonged to the local terrain without spending an eternity linking it to continuing terrain further west. So it is what it is.

Factoids:

According to the The Moon Observer’s Guide, Schickard is one of the Moon’s largest craters at 227 km in diameter. Its walls rise 2500 meters above the floor. Its southwestern floor has been noticeably disrupted by debris thrown from the Orientale impact over 1000 km to the west. This debris carved valleys and chains of craters along this part of the crater. Periods of lava flooding have given the crater floor a multi-toned appearance with darker sections in the northern and southeastern sections–the most striking example of this on the Moon’s face.

The crater intersecting the north side of Schickard is Lehmann Crater. Lehmann is 47 km wide (20.8% the width of Shickard–hahah!) with 800 m walls.

Subject Schickard and Lehmann Craters
Classification Lunar Craters
Position Southwest edge
Phase/Age 12 days old
Size* Schickard Crater: (dia. 227 km);
Lehmann Crater (dia. 47 km)
Date/Time January 22, 2005 – 9:15 PM (January 23, 2005 – 04:15 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 Clear, cool (34�F)
Seeing 4-5/10
Sources The Moon Observer’s Guide By Peter Grego
* Based on published data.

Jeremy Perez

Waning Blue

Daytime Moon

Daytime Moon
Sketch and Details by Frank McCabe

23 Day Old Waning Crescent

When the moon crossed my meridian today it was more than 75° above the southern horizon. That was about one hour before I began this sketch. The last time I purchased sketching paper I bought a few sheets of light blue paper for day time lunar and planet sketching. This August has been unusual for Chicago, Illinois, in that we have had many days with cool temperatures and low humidity. Today again was one of those very transparent days although clouds were frequent and stopped me from sketching from time to time. Actual sketching time was about 45 minutes over a two hour period.

Sketching:

For this sketch I used: light blue drawing paper cut to 12’x14”, white Conte’
pastel pencils, a light blue Crayola pencil, a blending stump and my index finger too. No adjustments were need after scanning except size reduction.
Telescope: 4.25 inch f/ 5 Dobsonian and 12mm eyepiece 45x

Date: 8-24-2008 13:00-15:00 UT
Temperature: 20° C (68° F)
Partly cloudy, calm
Seeing: Antoniadi III
Colongitude: 188°
Phase: 262.9°
Lunation: 23 days
Illumination: 44 %
Libration Latitude -6°
Libration Longitude -1°

Frank McCabe

Ray Crater Proclus at High Sun

Proclus

Ray Crater Proclus
Sketch and Details by Frank McCabe

Bright rayed crater Proclus (28 km.) lies between the highland Marsh of Sleep (Palus Somni) and the lowland Sea of Crisis (Mare Crisium). Proclus is a young crater about the same age as large crater Copernicus. But unlike Copernicus, the Proclus impact event arrived at an angle less than 15° from the west southwest based on the butterfly wing pattern of debris seen on the lunar surface. This pattern can be seen again on the eastern side of the moon several hundred kilometers to the south of Proclus with craters Messier and Messier A (not drawn here). The gray area to the upper right of Proclus is Palus Somni inside the “forbidden zone” where no rays can occur in the uprange direction. See chapter 10 of “The Modern Moon” by Charles Wood, Sky Publishing Corporation, for a more complete explanation. The rim of this crater in the high sunlight was as brightly illuminated as the rays. This crater is nearly as bright as larger Aristarchus across the lunar nearside to the west. Like crater Tycho this is one of those craters that are most impressive at high sun even with a modest size telescope. More than a lifetime of observing and even sketching awaits the amateur astronomer on moonlit nights.

Sketching

For this sketch I used: black Strathmore 400 Artagain paper 12”x8”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-6) and contrast increased (+5) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece 241 x
Date: 7-16-2008, 4:20-5:45 UT
Temperature: 25° C (76° F)
Clear, light winds
Seeing: Antoniadi III
Colongitude 67.6°
Lunation 13 days
Illumination 95.8 %

Frank McCabe

Luminous Goldschmidt

Goldschmidt Crater

Craters Goldschmidt, Anaxagoras and Epigenes
Sketch and Details by Frank McCabe

Crater Goldschmidt is an ancient pre-Nectarian period walled-plain crater that is situated only 480 km. from the lunar North Pole. The floor of this crater appears light in color and little crater Goldschmidt A (7km.) was seen on the southern floor.
Along the western rim of Goldschmidt are craters Anaxagoras (53 km.) and Anaxagoras A (18 km.). Anaxagoras is a young Copernican period crater with an expected ray system that includes some I saw during the observation and included here to the east and southeast. The crater to the southwest of Goldschmidt is Epigenes (55 km.), an ancient Nectarian period crater with a more typical dark floor for this region. With the moon crossing the meridian so low it never resolved well in the eyepiece and scintillated and shimmered in the warm air rising from the ground. All in all it was a wonderful opportunity to view and sketch the moon.

Sketching

For this sketch I used: black Strathmore 400 Artagain paper 10”x10”, white and black Conte’ pastel pencils and a blending stump. After scanning, Brightness was decreased (-5) and contrast increased (+5) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece 241 x
Date: 7-14-2008, 2:20-3:40 UT
Temperature: 20° C (68° F)
Partly Cloudy, calm
Seeing: Antoniadi III-IV
Colongitude 41.9°
Libration in Latitude: +7° 19’
Lunation 11 days
Illumination 84.3 %

Frank McCabe

Eddington: A Mere Shadow of its Former Self

Eddington

Eddington
Sketch and Details by Frank McCabe

I was disappointed with my previous observation of this region of the Ocean of Storms this past August and this night was my first opportunity to return to this area. On this evening of observing and sketching, 137 kilometer, walled-plain crater remnant Eddington was well positioned and illuminated in the morning sunlight for drawing. The features that identify Eddington as a large crater ruin include the missing southern and eastern rims and the vast flooding of its floor with the mare lavas. Eddington is a Pre-Nectarian period crater which is likely older than 4 billion years. Today its worn appearance still has character. There is a broken arc of rim remains from south to east which gradually climbs from hills to mountains as the rim arc is traced northward. It may no longer be a regal crater, but it makes an excellent bay to the shore of the Ocean of Storms. To the east-southeast of Eddington rests the much younger Eratosthenian period crater Seleucus (44 km.). This is a deep crater at 3 km. and has a bright meandering debris ray from the crater Oblers A (not seen) passing the crater to the east. The Soviet moon probe Luna 13 landed 75 kilometers southeast of this crater. South along the terminator is the crater Krafft (51 km.) which makes an interesting partner to crater Cardanus beyond the sketching region to the south. Two craters are visible north and east of Eddington. These craters are Briggs (37 km.) and Briggs B (25 km.). Both were showing dazzling rims and ramparts in the early sunlight. The lone crater visible across the sketch to the northeast is Imbrian period crater Schiaparelli at 24 kilometers in diameter. This was that perfect lighting I was waiting for to capture this little corner of the Ocean of Storms.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, white and black Conte’

pastel pencils and a blending stump. After scanning, Brightness was slightly decreased (-3) and contrast increased (+3) using Microsoft Office Picture Manager.

Telescope: 10 inch f/ 5.7 Dobsonian and 9 mm eyepiece 161x

Date: 6-17-2008, 2:55-3:50 UT

Temperature: 19° C (67° F)

Clear, transparent, calm

Seeing: Antoniadi III

Colongitude 72.7 °

Lunation 13.4 days

Illumination 98 %

Frank McCabe

Raising Eyebrows on the Floor of Imbrium

Aristillus and Autolycus

Aristillus and Autolycus
Sketch and Details by Richard Handy

Sitting replendently on the the eastern margin of Mare Imbrium, 56 km Aristillus and 41 km Autolycus, brothers of Copernician age, are a startling sight in the late lunar afternoon sunshine. Hexagonal in appearance, Aristillus’s broad and radially splayed glacis dominates the mare surface in this region. It’s wide, brilliantly lit terraces apparently have evidenced some mass wasting since its creation a little over a billion years ago. Resting on the floor, some 3650 m deep, the glowing central peaks are roughly 900 meters high. Rays, some quite prominent, emanate from the crater’s center. To the northwest of Aristillus, swathes of darker mare may indicate areas not fully dusted by the ejecta from this massive impact, or perhaps ejecta excavated from deep within the extant mare is responsible for these low albedo areas. Approximately 60 km to the south, Autolycus’s glacial nimbus appears almost serene in comparison to the complex nature of Aristillus’s glacis. Half of the floor of Autolycus is composed of quite torturous terrane including a strange floor subsidence to the eastern section of the floor.

Here are the sketch details:

Subject: Aristillus and Autolycus Rukl: 12
Date: 10-13-06 Start: 9:15 UT End: 10:50 UT
Lunation: 20.90 days Phase: 277.5 deg Illumination: 56.5%
Colongitude: 164.8 deg Lib. in Lat.: -5 deg 40 min Lib. in Long.: +7 deg 39 min
Seeing: Antoniadi III-IV with 30 seconds of Ant. II every 20 minutes
Weather: Clear early, turning to occasional clouds mid to late during session, 10-15 knot winds 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″

Across the Largest Lunar Lava Plain

Mare Imbrium

Mare Imbrium
Sketch and Details by Frank McCabe

Ray debris from crater Copernicus can be seen cast across this distant region of Mare Imbrium.
The first crater visible to the southeast (upper left) is 20 kilometer Pytheas. Like many of the craters in this part of the lava covered floor, it is from the Eratosthenian period and unlike the younger Copernican period craters does not display fresh crater rays. Northward the largest crater in this sketch is Lambert (30 km.). The inner wall terraces as well as the central craterlet were visible but the buried ghost crater Lambert R was not seen to the south with the higher sun angle here. To the west of Lambert the pair of bright spots is mons La Hire a solitary lunar mountain and remnant of the lunar highlands not covered over by lava. North of mons La Hire and projecting straight to the northwest is Dorsum Zirkel a wrinkled ridge of 200 kilometers length. Another shorter ridge to the northwest is Dorsum Heim which arcs to the northeast of crater Caroline Herschel (14 km.). The crater to the west of Pytheas and Lambert is Euler a 28 kilometer shadowed floor cavity with a brightly illuminated inner wall on the western side. Beyond this crater to the west southwest is the irregular, complex mountain feature mons Vinogradov an old Imbrian feature. On to the north northwest along the terminator are craters Diophantus (19 km.) and Delisle (25km.) with mons Delisle in between and closer to the crater of the same name. A dorsum or ridge or perhaps a buried crater rim creates a sharp curving demarcation between illumination and darkness along the terminator.
I would have preferred to use higher magnification during this observation but the wind was gusty and making observation a challenge.

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 8”x 11”, white and black Conte’pastel pencils and a blending stump. Brightness was slightly decreased (-2) and contrast increased (+3) after scanning using Microsoft Office Picture Manager.

Telescope: 10 inch f/5.7 Dobsonian and 12mm eyepiece 121x
Date: 4-16-2008 3:36 – 4:15 UT
Temperature: 9°C (48°F)
clear, windy
Seeing: Antoniadi III
Co longitude: 35.4°
Lunation: 10 days
Illumination: 82.9 %
Phase: 48.8°
Observing Location: +41°37′ .. +87° 47′

Frank McCabe

Walther’s Ray of Sunshine

Walther Crater Ray

Sunset Ray on the Floor of Walther

Crater Walther (formerly known as Walter) lies on the southern lunar highland’s great peninsula facing almost directly toward the earth. This is an ancient land, high, heavily bombarded and Walther is a Necterian age, 145 kilometer member. This walled-plain crater has tall terraced walls that tower 4 kilometers above the crater floor. The off center central peak stands 1.6 kilometers above the surrounding floor. The ancient rim is heavily cratered and has several incisura along its circumference created by impacts. Before sunset and at just the right time light penetrates through a notch in the western rim and sprays light across the floor to the central peak and several floor crater rims beyond in an eastward direction. The remainder of the floor is completely dark creating the frozen searchlight view that I attempted to capture in this sketch. West of the notched wall is crater Deslandres W with its large rim blocks which separates it from the hellplain, Deslandres to the west. Walther also has a sunrise ray that can be seen beyond first quarter at just the right time.

The following webpage gives the times of lunar ray events for craters including Walther. http://www.lunar-occultations.com/rlo/rays/rays.htm

Sketching:

For this sketch I used: black Strathmore 400 Artagain paper, 8”x 8”, 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: 11-2-2007 11:40-12:40 UT
Temperature: 0°C (32°F)
Clear, calm
Seeing: Antoniadi III
Co longitude: 115.4°
Lunation: 22.3 days
Illumination: 43.6 %

Frank McCabe


Note to visitors: Frank dedicated this stunning sketch to Rich Handy last week in the Cloudy Nights sketching forum. Thank you Frank. I’m sure we all echo your wish that Rich have a speedy rebuild and return home.

Jeremy

The Compelling Late Old Moon

The compellling Late Old Moon

South is up and west is to the left in this sketch I made this morning near
daybreak of day 27 for lunation 1048. I knew the view would be poor because I
could not wait at all for the scope’s primary mirror to cool down. Therefore I
kept the magnification low and decided to sketch the compelling region from the
Ocean Procellarum to Sinus Roris. At the top of the sketch closest to the lunar
equator and near the terminator, you can see crater Reiner a 53 km. crater and to
the west of this crater is the famous bright feature Reiner Gamma. Crater Olbers
responsible for the rays in the region is lost in the bright area near the limb.
Most of the craters in this late lunation have floors in darkness and look quite
spectacular through the eyepiece. The longest bright ray from south to north
passes east of the crater pair Cardanus and Krafft both about 50 km. in diameter.
On northward a couple of hundred kilometers and just west of the bright ray the
dark crater Seleucus can be  seen and further along to the east of the ray lies Schiaparelli. Most of the remaining craters visible lie on the limb side of the continuing ray and include: large crater Russell (105 km.) with smaller Briggs and Briggs A just to the east.
  Continuing on northward across the dark smooth ocean, craters Lichtenberg and
larger Lavoisier A can be seen. At this point the bright limb highlands feature
Harding and Dechen showing bright ejecta blankets near the edge of Sinus Roris. On
the terminator side  dome complex Mons Rumker is about to experience sunset.
Finally at the far northern end of the sketch is Markov a 40 km crater on the
floor of Sinus Roris. Seeing the moon early in the morning late in a lunation is
always a  pleasant and memorable sight.
  
  Sketching:
  For this sketch I used: black Strathmore 400 Artagain paper 12”x 7”, white and
  black Conte’ pastel pencils a blending stump and my index finger too. Brightness
  was slightly adjusted after scanning.
  Telescope: 10” inch f/ 5.7 Dobsonian and 21mm eyepiece 69x
  
  Date: 10-8-2007 10:30-11:15 UT
  Temperature: 22° C (72° F)
  Clear, calm
  Seeing: Antoniadi III
  Colongitude: 234.1 °
  Lunation: 27 days
  Illumination: 7 %
  
  Frank McCabe