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A publication of the Lunar Section of ALPO Edited by David Teske: [email protected] 2162 Enon Road, Louisville, Mississippi, USA issues: http://www.alpo-astronomy.org/

Online readers, November 2020 click on images In This Issue for hyperlinks

Lunar Calendar October 2020 2 An Invitation to Join ALPO 2 Observations Received 3 By the Numbers 5 Submission Through the ALPO Image Achieve 6 When Submitting Observations to the ALPO Lunar Section 7 Call For Observations Focus-On 7 Focus-On Announcement 8 of Heraclitus, R. Hill 9 - Region, H. Eskildsen 10 Orientale (the image that almost wasn’t) H. Eskildsen 11 Northern , H. Eskildsen 13 A 3D Moon, V. H. Cabrera and D. G. Teyssier 14 Taurus- Base, R. Hill 17 , H. Eskildsen 18 Dorsa Geikie, A. Anunziato 24 An “X” Northeast of Nicollet, S. Babino and A. Anunziato 25 Size Comparison Between Full Perigee and Apogee in 2020, V. H. Cabrera and D. G. Teyssier 28 Shadowplay, R. Hill 29 Central Ridgets on Heraclitus and Stöfler, A. Anunziato 30 Searching Lunar Domes in : The Dome Crisium 1 Near G (Preliminary Report), R. Lena 32 ALPO Banded Crater Program 38 Focus-On Lunar Targets 31-40, J. Hubbell 40 Recent Topographic Studies 53 Lunar Geologic Change Detection Program T. 82 Key to Images in this Issue 88

This issue features a number of interesting articles about the Moon including the very popular Focus- On Lunar Targets by Jerry Hubbell. Howard Eskildsen and Robert Hays, Jr. added articles that compli- mented these Focus-On targets. The apparent size of the Moon is explored in two articles by Victor Cabrera and Diana Teyssier. Alberto Anunziato and Sergio Babino highlight various lunar targets, as does Rik Hill. Raffaello Lena allowed some of his wonderful research to grace our pages. As al- ways, Tony Cook presents a thorough and interesting Lunar Geologic Change Detection article. Howard Eskildsen has begun research again in the ALPO Banded Craters Program. Many thanks to all contribu- tors here. Clear skies and be safe! -David Teske

The Lunar Observer/November 2020/ 1

Lunar Calendar November 2020

Date Time UT Event November 5 0200 Moon 0.2o north of M35 6 Greatest northern declination of the Moon, +24.8o 8 West limb most exposed -7.4o 8 1346 Last Quarter Moon 11 South limb most exposed -6.7o 12 2100 3o south of Moon 13 2100 1.7o south of Moon 14 1200 Moon at perigee 357,837 km, large 15 0507 , lunation 1211 18 Greatest southern declination of the Moon -24.7o 19 0900 2o north of Moon 19 1500 3o north of Moon 20 East limb most exposed +7.5o 22 0445 First Quarter Moon 24 North limb most exposed +6.8o 25 2000 Moon at apogee 405,894 km 30 0930 , penumbral magnitude 0.828, visible in much of the West- ern Hemisphere

The Lunar Observer welcomes all lunar related images, drawings, articles, reviews of equipment and reviews of books. You do not have to be a member of ALPO to submit material, though membership is highly encouraged. Please see below for membership and near the end of The Lunar Observer for submission guidelines.

Comments and suggestions? Please send to David Teske, contact information page 1. Need a hard copy, please contact David Teske.

AN INVITATION TO JOIN THE A.L.P.O.

The Lunar Observer is a publication of the Association of Lunar and Planetary Observers that is available for access and participation by non- members free of charge, but there is more to the A.L.P.O. than a monthly lunar newsletter. If you are a nonmember you are invited to join our organization for its many other advantages. We have sections devoted to the observation of all types of bodies found in our solar system. Section coordinators collect and study members’ observations, correspond with observers, encourage beginners, and contribute reports to our Jour- nal at appropriate intervals. Our quarterly journal, The Journal of the Association of Lunar and Planetary Observers-The Strolling Astronomer, contains the results of the many observing programs which we sponsor including the drawings and images produced by indi- vidual amateurs. Additional information about the A.L.P.O. and its Journal is on-line at: http://www.alpo-astronomy.org. I invite you to spend a few minutes browsing the Section Pages to learn more about the fine work being done by your fellow amateur astronomers. To learn more about membership in the A.L.P.O. go to: http://www.alpo- astronomy.org/main/member.html which now also provides links so that you can enroll and pay your membership dues online.

The Lunar Observer/November 2020/ 2

Lunar Topographic Studies

Coordinator – David Teske - [email protected] Assistant Coordinator – William - [email protected] Assistant Coordinator – Jerry Hubbell – [email protected] Assistant Coordinator-Wayne Bailey– [email protected] Website: http://www.alpo-astronomy.org/

Observations Received

Name Location and Organization Image/Article Jay Worth, Florida, USA Images of , Schickard and Tri- esnecker. Alberto Anunziato Paraná, Argentina Drawing and article Dorsa Geikie, An “X” Northeast of Nicollet; Observing the Bottom of , Central Ridgets on Heraclitus and Stöfler, imag- es of Copernicus (2), , Schickard and drawings of Arago (3). Sergio Babino Montevideo, Uruguay Images and article An “X” Northeast of Nicollet; Observing the Bottom of Mare Nubium, images of Arago, the Serpen- tine Ridge, , (2) and . Juan Manuel Biagi Oro Verde, Argentina Images of Lacus Mortis and Grimaldi. Victor Cabrera Astronomical Society of Puebla – Articles and images A 3D Moon and Size “German Martinez Hidalgo” SAP-GMH, Comparison Between Full Moons Peri- city of Puebla, Mexico. gee and Apogee in 2020. Francisco Alsina Cardinalli Oro Verde, Argentina Image of Mare Nubium, Taruntius, the Serpentine Ridge (3), Lacus Mortis (2), (4), Grimaldi (2), Sab- ine, Schickard and . Jairo Chavez Popayán, Colombia Image of the Full Moon. Howard Eskildsen Ocala, Florida, USA Articles and images Pythagoras- Carpenter Region, Orientale (the image that almost wasn’t), Northern Moon, Taruntius, images of banded crater Aris- tarchus, banded crater , banded crater and banded crater Pytheas. Fernando Gimenez Montevideo, Uruguay Image of . Desiré Godoy Oro Verde, Argentina, SLA Image of Taruntius. Martín Queirolo Gomez Montevideo, Uruguay Image of Schickard. Marcelo Mojica Gundlach Cochabamba, Bolivia Image of Janssen.

Many thanks for all these observations, images, and drawings.

The Lunar Observer/November 2020/ 3

Lunar Topographic Studies

Coordinator – David Teske - [email protected] Assistant Coordinator – William Dembowski - [email protected] Assistant Coordinator – Jerry Hubbell – [email protected] Assistant Coordinator-Wayne Bailey– [email protected] Website: http://www.alpo-astronomy.org/

Observations Received

Name Location and Organization Image/Article Robert H. Hays, Jr. Worth, Illinois, USA Articles and drawings Arago & Man- ners, Triesnecker and , Sabine, and . Rik Hill Loudon Observatory, Tucson, Arizona, Articles and images North of Heraclitus, USA Taurus-Littrow Base and Shadowplay. Jerry Hubbell Wilderness, Virginia, USA Image of the 21 and 22 day old Moon, article and images Focus-On Lunar Tar- gets 31-40. Raffaello Lena Rome, Italy Images of , Stadius and and article Searching Lunar Domes in Mare Crisium: The Dome Crisium 1 Located Near Cleomedes G (Preliminary Report) Pedro Romano San Juan, Argentina Images of Plato, Copernicus (2), and the Serpentine Ridge.

Leandro Sid AEA, Oro Verde, Argentina Images of Copernicus (3), and the Waxing Gibbous Moon.

Fernando Surà San Nicolás de los Arroyos, Argentina Image of Plato. David Teske Louisville, Mississippi, USA Images of the Serpentine Ridge, Grimal- di Basin, Sabine and Ritter and Janssen. Diana Garcia Teyssier Astronomical Society of Puebla – Articles and images A 3D Moon and “German Martinez Hidalgo” SAP-GMH, Size Comparison Between Full Moons city of Puebla, Mexico. Perigee and Apogee in 2020. Román García Verdier Paraná, Argentina Images of , and Stevi- nus.

Many thanks for all these observations, images, and drawings.

The Lunar Observer/November 2020/ 4

November 2020 The Lunar Observer By the Numbers

This there were 78 observations by 22 countries in 7 countries.

The Lunar Observer/November 2020/ 5

SUBMISSION THROUGH THE ALPO IMAGE ARCHIVE ALPO’s archives go back many years and preserve the many observations and reports made by am- ateur astronomers. ALPO’s galleries allow you to see on-line the thumbnail images of the submitted pictures/observations, as well as full size versions. It now is as simple as sending an email to include your images in the archives. Simply attach the image to an email addressed to [email protected] (lunar images). It is helpful if the filenames follow the naming convention : FEATURE-NAME_YYYY-MM-DD-HHMM.ext YYYY {0..9} Year MM {0..9} Month DD {0..9} Day HH {0..9} Hour (UT) MM {0..9} Minute (UT) .ext (file type extension) (NO spaces or special characters other than “_” or “-”. Spaces within a feature name should be replaced by “-”.) As an example the following file name would be a valid filename: Sinus-Iridum_2018-04-25-0916.jpg (Feature , Year 2018, Month April, Day 25, UT Time 09 hr16 min) Additional information requested for lunar images (next page) should, if possible, be included on the image. Alternatively, include the information in the submittal e-mail, and/or in the file name (in which case, the coordinator will superimpose it on the image before archiving). As always, additional commentary is always welcome and should be included in the submittal email, or attached as a separate file. If the filename does not conform to the standard, the staff member who uploads the image into the data base will make the changes prior to uploading the image(s). However, use of the recommended for- mat, reduces the effort to post the images significantly. Observers who submit digital versions of draw- ings should scan their images at a resolution of 72 dpi and save the file as a 8 1/2'“x 11” or A4 sized picture. Finally a word to the type and size of the submitted images. It is recommended that the image type of the file submitted be jpg. Other file types (such as png, bmp or tif) may be submitted, but may be converted to jpg at the discretion of the coordinator. Use the minimum file size that retains image detail (use jpg quality settings. Most single frame images are adequately represented at 200-300 kB). How- ever, images intended for photometric analysis should be submitted as tif or bmp files to avoid lossy compression. Images may still be submitted directly to the coordinators (as described on the next page). However, since all images submitted through the on-line gallery will be automatically forwarded to the coordinators, it has the advantage of not changing if coordinators change.

The Lunar Observer/November 2020/ 6

When submitting observations to the A.L.P.O. Lunar Section In addition to information specifically related to the observing program being addressed, the fol- lowing data should be included:

Name and location of observer Name of feature Date and time (UT) of observation (use month name or specify mm-dd-yyyy-hhmm or yyyy-mm-dd-hhmm) Filter (if used) Size and type of used Magnification (for sketches) Medium employed (for photos and electronic images) Orientation of image: (North/South - East/West) Seeing: 0 to 10 (0-Worst 10-Best) Transparency: 1 to 6

Resolution appropriate to the image detail is preferred-it is not necessary to reduce the size of im- ages. Additional commentary accompanying images is always welcome. Items in bold are re- quired. Submissions lacking this basic information will be discarded.

Digitally submitted images should be sent to: David Teske – [email protected] Jerry Hubbell –[email protected] Wayne Bailey—[email protected]

Hard copy submissions should be mailed to David Teske at the address on page one.

CALL FOR OBSERVATIONS: FOCUS ON: Lunar 100 Focus on is a bi-monthly series of articles, which includes observations received for a specific fea- ture or class of features. The subject for the January 2021 edition will be the Lunar 100 numbers 41-50. Observations at all phases and of all kinds (electronic or film based images, drawings, etc.) are welcomed and invited. Keep in mind that observations do not have to be recent ones, so search your files and/or add these features to your observing list and send your favorites to (both): Jerry Hubbell –[email protected] David Teske – [email protected]

Deadline for inclusion in the Lunar 100 numbers 41-50 article is December. 20, 2020

FUTURE FOCUS ON ARTICLES: In order to provide more lead time for contributors the following future targets have been selected: The next series of three will concentrate on subjects of the Selected Areas Program.

Subject TLO Issue Deadline Lunar 100 (numbers 41-50) January 2021 December 20, 2020 Lunar 100 (numbers 51-60) March 2021 February 20, 2021

The Lunar Observer/November 2020/ 7

Focus-On Announcement

We are pleased to announce the future Focus-On topics. These will be based on the Lunar 100 by Charles Wood. Every other month starting in May 2020 , the Focus-On articles will explore ten of the Lunar 100 targets. Targets 41-50 will be featured in the January 2021 The Lunar Observer. Submissions of articles, drawings, images, etc. due by December 20, 2020 to David Teske and Jerry Hubbell.

L FEATURE NAME SIGNIFICANCE RUKL CHART 41 Bessel ray Ray of uncertain origin near Bessel 24

42 Hills Complex of volcanic domes and hills 28, 29 43 Wargentin A crater filled to the rim with or ejecta 70 44 Domed floor cut by secondary craters 51 45 Region of saturation cratering 66 46 Regiomontanus central Possible volcanic peak 55 peak 47 Alphonsus dark spots Dark-halo eruptions on crater floor 44 48 region Fault, rilles and domes 36 49 Delta & Volcanic domes formed with viscous lava 9

Gamma 50 Plains Light, smooth plains of uncertain origin 34 Explore the Lunar 100 on the below: https://www.skyandtelescope.com/observing/celestial-objects-to-watch/the-lunar-100/

The Lunar 100: Features 1-10 May 2020 Issue – Due April 20, 2020 The Lunar 100: Features 11-20 July 2020 Issue – Due June 20, 2020 The Lunar 100: Features 21-30 September 2020 Issue – Due August 20, 2020 The Lunar 100: Features 31-40 November 2020 Issue – Due October 20, 2020 The Lunar 100: Features 41-50 January 2021 Issue – Due December 20, 2020 The Lunar 100: Features 51-60 March 2021 Issue – Due February 20, 2021 The Lunar 100: Features 61-70 May 2021 Issue – Due April 20, 2021 The Lunar 100: Features 71-80 July 2021 Issue – Due June 20, 2021 The Lunar 100: Features 81-90 September 2021 Issue – Due August 20, 2021 The Lunar 100: Features 91-100 November 2021 Issue – Due October 20, 2021 Jerry Hubbell –[email protected] David Teske – [email protected]

The Lunar Observer/November 2020/ 8

South of Heraclitus Rik Hill

Early in every lunation you can see this region on the Moon and though I have covered it before, I discov- ered some remarkable new things on this particular visit. First a little orientation. Notice the Mickey Mouse configuration in the upper left. The left ear is the crater Licetus (77 km) and the right is (also 77 km). Between them is the unusual north-south elongated feature, Heraclitus with an odd central ridge. This is the result of a merger of two or three craters. The large flat floored crater near the center of this image is Manzinus (100 km). Then the large crater on the right edge of this image with the central peak is Vlacq (92 km). This should serve to give the outlines.

When processing this image, a montage of two images, I thought I saw an artifact of the knitting process about midway up the . It’s a little dotted horizontal line and above the left end the barest outlines of the east walls of two vertically-oriented craters still deep in . After examining numerous images of this area taken over the last 10 years that are in the Loudon Observatory Lunar Image archive (https:// www.lpl.arizona.edu/~rhill/moonobs.html) I was finally convinced that these are the regularly spaced tips of a row of peaks and crater walls. On the east (right) end of this line is a large crater in the shadow with ‘ears’ of two smaller craters, also in shadow. The larger crater is Zach (73 km) and the adjacent crater to the east (right) is Zach D (32 km), while the one to the west is the Zach F (28 km) crater. That would make the line of the two vertical craters and (49 km) itself to the north. Deluc H (26 km) can be just made out above this. So, what I at first feared was an artifact was in fact quite real! If I had noticed this at the time, I was imaging I would have tried to repeat the observation as the rising revealed more of the features themselves. Just another example that the appearance of things on the Moon can change quickly on the Moon.

South of Heraclitus, Richard Hill, Loudon Observatory, Tuc- son, Arizona, USA. 30 April 2020 02:15 UT, colongitude 355.6o. Dynamax 6 ich Schmidt- telescope, Goodwin Barlow, 665 nm filter, Skyris 445 M camera. Seeing 8/10.

The Lunar Observer/November 2020/ 9

Pythagoras-Carpenter Region Howard Eskildsen

Seeing was marginal to poor last night, but I did these images anyway. I had all my other images processed and was eager to proceed. The Moon has favorable for the northeast limb currently and will be at times over the next couple of lunations.

Crater Pythagoras (129 km diameter) has a spectacular central peak and lies just to the upper left of center in this image. To its upper right the battered rests between Pythagoras and Carpenter (60 km in diameter). The ruined crater lies just above Anaximander, and to its upper right, has a dis- cernible central peak emerging from the partly shadowed floor. Two small craters on the upper rim of Pascal peer like eyes across the scene.

To the lower left of Pythagoras, the squared off crater of contains two small craters on its interior. Below it another square crater, South, abuts a rectangular peninsula-like formation on its right, and beyond the "peninsula," crater J Herschel is just barely visible. These craters were sculpted, or should I say battered, by ejecta from the Imbrium impact, but how they ended up square is challenging to imagine.

Mare Frigoris crosses the lower part of the image streaked by various ray and pocked by small craters. The 40 km Harpalus stands out on the lower image margin, just left of center.

Pythagoras and Carpenter, Howard Eskildsen, Ocala, Florida, USA. 01 October 2020 01:52 UT, colongitude 78.3o. Celestron 9.25 inch Schmidt-Cassegrain telescope, f/10, fl 2395 mm, Celestron Skyris 236M camera. Seeing 5/10, transparency 4/6.

The Lunar Observer/November 2020/ 10

Orientale (the image that almost wasn't) Howard Eskildsen

I arose at 5 AM Sunday hoping to get an image of during this rare, very favorable libration. was barely visible through clouds, but the moon cast in the back yard so there was some hope. A quick check revealed a significant gap in the clouds near the moon, so I set up as efficiently as pos- sible. After a very brief visual observation, the camera was attached, focused and two images were taken. I didn't like the exposure settings and two more images were taken with no hint of cloud intrusion. Then, sat- isfied with the results, I repositioned to a target of opportunity, since seeing was quite good. Halfway through that video imaging, the Moon faded and then disappeared. I had gotten Mare Orientale with only a couple of minutes to spare. Fortunately, sprinkles of rain waited until I had the telescope safely back in the shed.

This rare, extreme lunar libration reveals four rings of Orientale basin: a 320 km inner ring partly defined by the margin of Mare Orientale, the 480 km ring of the inner Rook range, the 620 km diameter ring of (outer range) and the 930 km diameter ring of . The mountain ranges can be seen curving around the north and south margins of the basin, separated by relatively smooth plain in the low- lands between the ranges. Several seldom-seen craters within the basin are labeled. It was a bit of a thrill to note craters that I had never seen before.

Lacus Veris separates the inner and outer Rook ranges while lies in the lowlands between Montes Rook and Montes Cordillera. "Mare Pacificus" lies on both sides of the arc of Montes Rook and, unlike the mare of the basin, it is a pyroclastic ring that erupted from a V-shaped vent (not visible on this image) located about half way between the two arrowheads on the image. Mare Pacificus is an unoffi- cial name that was proposed by Soviet scientists.

Beyond of the outer basin rim, other effects of the Orientale impact are visible. Rugged ejecta radiates across the image and is likely buried beneath younger flows of on the lower right of the image. It is also likely that the ejecta buries prior mare deposits, notably in the region of Crüger and which winds its way to the upper right of Crüger. Below Crüger, Rima Sirsalis courses across the image towards Brygius A which splashed its bright rays all over the Orientale ejecta.

On the upper right of the image, dark basalt covers part of the floors of Schlüter and of . Grimaldi, however, has its floor nearly completely covered with mare basalt and close examination of the surrounding areas shows that it has an inner ring (222 km diameter) and an outer ring (430 km diameter) and is in fact an impact basin that was emplaced before Orientale, and later battered by that basin-forming impact.

The Lunar Observer/November 2020/ 11

Mare Orientale, Howard Eskildsen, Ocala, Florida, USA. 11 October 2020 09:28 UT, colongitude 203.9o. Celestron 9.25 inch Schmidt-Cassegrain telescope, f/10, fl 2395 mm, Celestron Skyris 236M camera. Seeing 7/10, transparency 3/6.

The Lunar Observer/November 2020/ 12

Northern Moon Howard Eskildsen

The moon has had favorably libration for the northern and northeastern region. This will repeat the next cou- ple of and offers opportunity to view seldom-seen lunar features.

Anaxagoras splashes its bright rays across the image while seldom-seen craters to the north lurk in the libra- tion zone. , , , and serve as the stepping stones to the polar craters, and Pea- ry. The north pole of the Moon is located on the upper rim not far from the top of the letter "P" in . Further terrain is visible beyond this, which I like to think of as "south of north."

Hermite and are seen with rare clarity during this north-favoring libration. Other neglected craters in the area include , Euctemon, and . , however, on the left edge of the image is bet- ter known due to its distinctive double central peaks.

North Polar Region, Howard Eskildsen, Ocala, Florida, USA. 01 October 2020 01:52 UT, colongitude 78.3o. Celes- tron 9.25 inch Schmidt-Cassegrain telescope, f/10, fl 2395 mm, Celestron Skyris 236M camera. Seeing 5/10, trans- parency 4/6.

The Lunar Observer/November 2020/ 13

A 3D Moon Víctor Hugo Cabrera‐Peláez and Diana García‐Teyssier

Stereoscopic vision is the ability of the human brain to integrate into a single three‐dimensional image, in relief and with sufficient depth, the two slightly different images that come to us from each of our eyes. In the case of the moon, in order to create two slightly different images, it is necessary take one shot to the moon as close as you can after moonrise, wait for almost 12hr to take other shot a few minutes before the moonset. The geometry of the figure helps us to calculate the stereoscopic viewing angle and to give us an idea of the model scale.

Figure 1 Geometry to capture images in order to create a stereogram of the moon.

By using a 120mm aperture refractor telescope with a 2.5x Barlow we have 150x of magnification so if the moon’s angular size is about 0.5°, in the sensor have a size of 75° so, observing through a telescope is equivalent to approaching the moon, in this case it is as if we were in a point 4200mi (6746.22km) far from moon surface. To give us an idea, if the diameter were the eyes separation, the moon diameter would be 0.6945in (17.64mm) and would be at 7ft,4.58in (2.25m) from our face, but with the telescope we can ob- serve it at a distance of 15in (37.5cm). Due the use of an equatorial mount the images are rotated 180° be- tween them, so we can rotate them ±90° and put both of them together with a size of 2in (5cm) but separated 2.5625in (65mm), it is similar to observe the image in the cellular screen, as in stereographic devices, we can use a separator to see each image only with one eye. The result is shown in the next pair of photographs, to observe it, please place the screen about 10in (25cm) from your eyes, place a piece of paper from the mid- dle of the image to your nose, so that you can only see one moon with each one eye, let your brain compose the image and enjoy a stereogram of the moon; at this point if you move your neck the image show you a 3D spherical moon.

If you observe each image of the moon there are a little difference in the right‐left edges, they are not possi- ble called libration, is then the perspective of observing the moon with 9 degrees of difference by the way, in the scale, is similar to observing an image of the moon of 2in (5cm) to 10 in (25cm) away. If we take the figure 2 and using photoshop we can merge the images in a JPS format and create an anaglyph (figure 3) of the moon the resulting image is shown below.

The Lunar Observer/November 2020/ 14

Figure 2 Moon Stereogram Figure 3 Anaglyph Moon below

The Lunar Observer/November 2020/ 15

A 3D-Moon.pdf is the brief description about the photographs

2020-10-02-0043-VHCP-DGT-CalculusAndGeometry.png is the geometry used to compose images.

2020-10-02-0043And1220-VHCP-DGT-StereoscopyMoon.jpg and 2020-10-02-0043And1220-VHCP-DGT -AnaglyphMoon.jpg are the images of a 3D-moon and following the format submission: Observers: Victor Hugo Cabrera-Peláez and Diana García-Teyssier, Astronomical Society of Puebla – “German Martinez Hidalgo” SAP-GMH, city of Puebla (19.00972 ° N, -98.2036 ° W), Mexico.

Name of feature: 3D Stereogram and anaglyph of the moon. Date and time of observation: October 02 at 01:02hr UTC and 12:20hr UTC Without filter, but focusing with a diffraction mask of my own design. Refractor telescope of 120mm aperture and f/8.3 with a 2.5 Barlow lens attached to the camera. In both of them 20 individual photographs were taken with a Sony A7 camera with ISO 100, with a time of 1/25s. captured in RAW format and stacked-enhanced in Photoshop. The anaglyph was composed and saved in a JPS format, after converted into a JPG image.

In the images moon's north is at top because the photographs were rotated ±90° due the camera was attached to a telescope with equatorial mount aligned to the north with an introscope 2x and corrected by drift. Seeing of 7 Transparency of 4

The Lunar Observer/November 2020/ 16

Taurus-Littrow Base Rik Hill

South and east of is the crater Römer (41 km) seen here at the top of this image with starkly ter- raced walls and an off-center peak on its floor. It’s a young crater and its shape is strongly affected by the topography it was created in. Twin 12 km craters below it, on the left and a little lower on the right is . These both sit in the western reaches of with Mons , a round mound on the southern shore of the Sinus just north of the low walled crater Maraldi (41 km). Moving further south is the crater (19 km) and to its west (left) is the flat floored (31 km), half in shadow. South and west of Vitruvius is a smaller crater, (19 km) with an interesting set of ridges on the east side of the crater, followed by (44 km) with Rimae Plinius and Promontorium Archerusia next to it.

Notice north and west of Vitruvius there are four similar mountain peaks in a row all catching the early morning sunlight. They mark the location of the 17 landing site marked here with an “O”. It is one of the easiest Apollo landing sites to find and once you learn it, Taurus-Littrow will always stand out. The “O” sits in Taurus-Littrow with South Massif being the sunlit mountain to the south and the dimmer light just north of the “O” is North Massif. The little dot to the lower right of the “O” is Bear Mountain named by Harrison Schmidt after a mountain near his hometown in Silver City, New Mexico. Details can be seen in images taken from overhead at the URL: www.lpi.usra.edu/lunar/missions/apollo/apollo_17/ landing_site/. All the EVAs and the 37 km of driving in the “Moon Buggy” was done inside that circle and included the most time of any crew on the lunar surface collecting 110.4 kg of surface samples.

North of the landing site is the flat floored teardrop shaped crater Littrow (19 km) and to the left is a field of rimae called Catena Littrow with the small crater (7 km) between them. The rimae are graben- like and therefore fairly wide, about 2 km on the average. Going further north, following the or dorsa that leads that leads out of the Catena we come nearly full circle with the embayment Le Monnier (63 km), a very distinctive feature.

Apollo 17 Site, Richard Hill, Loudon Observatory, Tucson, Arizona, USA. 08 July 2019 02:42 UT, colongitude 339.0o. 8 inch f/20 Maksutov-Cassegrain tele- scope, 610 nm filter, Skyris 445 M cam- era. Seeing 9/10.

The Lunar Observer/November 2020/ 17

Taruntius Howard Eskildsen

The floor-fractured crater Taruntius (Figure 1) lies at the north end of , center 46.5ᵒ E and center latitude 5.5ᵒ N per LROC QuickMap. Its floor has been elevated producing arcuate rilles, Rimae Taruntius, reminiscent of smaller concentric craters. With a diameter of 57.3 km and a depth of 1228m (per QuickMap), its depth (d)/diameter (D) ratio calculates to 0.021. This compares to a "Height/ Wide Ratio" of 0.0214 per the Virtual Moon version 7.0 (VMA7). This is shallower than would be expected in a non-floor-fractured crater. For comparison, 68 km has a d/D ratio of 0.05 per VMA7, but does not appear to have uplift of its floor. This suggests that the floor or Taruntius was uplifted approxi- mately 1600 meters, assuming that it originally had a d/D of 0.05.

Taruntius, Howard Eskildsen, Ocala, Florida, USA. 25 December 2018 03:50 UT, 6 inch f/8 refractor telescope, Ex- plore Scientific lens, 2 x barlow, W-8 yellow filter, DMK 41AU02.AS 236M camera. Seeing 7/10, transparency 5/6.

The question has been raised in the past if the central peak of Taruntius might be higher than the rim of the crater due to this uplift. Figure 2 shows sampling paths from LROC Quickmap that were used in calcula- tions. Paths AB and CD were used to calculate crater depth, Path GH was used to determine which summit of the central peak complex was highest. Figure 3 shows LOLA data from the Lunar Reconnaissance Orbiter () and reveals that the northwest summit is highest. Figures 4 and 5 are the elevation paths used to cal- culate the crater floor depth, but also show that the central peak is lower than the rim along those paths. However, Figure 6 shows that the central peak is indeed higher than the northeast rim along the sampling path EF shown on Figure 2.

The Lunar Observer/November 2020/ 18

Figure 2

Figure 3

The Lunar Observer/November 2020/ 19

Figure 4 above, Figure 5 below

The Lunar Observer/November 2020/ 20

Figure 6

Taruntius has been considered a "young" floor fractured crater of Copernican age since it has visible rays, however, a study using remote sensing data, including soil maturity indicators, showed that the rays are compositional and are fully mature, implying that Taruntius and other craters in the study should be consid- ered Eratosthenian in age. (Lunar and Planetary Science XXXVII (2006) 1133.pd THE COMPOSITION AND ORIGIN OF LUNAR CRATER RAYS: IMPLICATIONS FOR THE COPERNICAN- ERATOSTHENIAN BOUNDARY. B.R. Hawke, et al)

On the northwest rim of Taruntius, an oblique impact created 10.9 km crater as seen in LROC im- age of Figure 7. The zone of avoidance indicates the impactor approached from the east-northeast and thin, bright rays accent the V-shaped margin of the avoidance zone while dark rays radiate in other directions. Curiously the dark rays appear to split where they encounter the rim of Taruntius, raising the question if this distribution was affected by the terrain, or if it is merely a chance alignment of the expected downrange ray of an oblique impact.

Figures 8 and 9 show the UVVIS FeO Abundance and Color-Ratio overlays respectively. The thin, bright rays appear low in iron, relatively high in titanium, and a small triangular area of similar compo- sition is noted extending from the wall to the crater floor. The dark rays are high in iron and low in titanium. Hence there appears to be a compositional difference between the bright thin rays and the remainder of the dark rays. The bright rays are not highland material, which is usually seen as red in the color-ratio render- ings of Clementine. Perhaps the Cameron-forming object impacted fortuitously where basaltic with lower iron and high titanium had intruded into surrounding high iron, low titanium basalts.

It is exciting to see how much can be observed by looking closely, especially since various orbiters' data of- fer so many more ways to look.

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Figure 7

Figure 8

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Figure 9

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Dorsa Geikie Alberto Anunziato

This is how the system of wrinkle ridges known as Dorsa Geikie, which stretches 220 kilometers in the Mare Fecunditatis, can be observed at 319.7º colongitude. We see it in the section corresponding to the vi- cinity of Lindbergh (13 kilometers in diameter) to the north and (12 kilometers in diameter) to the south. Comparing images of this lunar feature after the observation, I could see that in this observation less detail is seen than in the few images available, which is contrary to what usually happens in the visual observation of dorsa near the terminator, when visually we could observe more details than those that appear in the images. South of Lindbergh Dorsa Geikie is interrupted in our image, although in reality it is not, as we could see, for example in the “Photographic Lunar Atlas for Moon Observers” by Kwok C. Pau. The play of shadows and lights towards the west (towards the terminator) and the bright sections towards the southeast appear more conspicuous than its very low height would suggest, only with sunlight at such a low angle will we see these eastern sections so neatly.

Dorsa Geikie, Alberto Anunziato, Paraná, Argentina. 22 August 2020 23:00 –23:25 UT. Meade EX 105 Maksutov- Cassegrain telescope, 154 x.

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An “X” Northeast of Nicollet Observing the Bottom of Mare Nubium Sergio Babino and Alberto Anunziato

In an image focused on the majesty of Tycho at full moon, we ended up finding a bright "X" in the Mare Nubium, we found it in the green circle (image 1). The colongitude is 88º and the sunlight falls frontally, there are no shadows, not the ideal conditions to observe wrinkle ridges and what we see is clearly a dor- sum. It can be seen more clearly in the enlargement (image 2), the crater with very bright rims on the left is Nicollet (15 km in diameter).

Figure 1. Tycho, Sergio Babino, Montevideo, Uruguay. 08 May 2020 02:48 UT. 203 mm catadrioptic telescope, Baader continuum filter, ZWO ASI 174 mm camera. Figure 2. Close-up below.

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Regarding the dimensions of this “X”, the image was taken with a Celestron CPC800 with 2032mm focal length and captured with a CMOS ZWO174MM camera with a pixel of 5.86 microns which gives a scale per pixel of 0.595 arcsec/px. Measuring the major axis is 24.827″ and the minor 15.618″ which translated into distance on the Moon would be a size of 55 X 30 kms. approximately. In this 3D graph (image 3) we can see the heights of the relief of the area included in image 2 (White upper /green lower).

Figure 3. Tycho 3D, Sergio Babino, Montevideo, Uruguay. 08 May 2020 02:48 UT. 203 mm catadrioptic telescope, Baader continuum filter, ZWO ASI 174 mm camera.

The Nicollet cone shape and the great height of the edges of this Eratosthenian crater are interesting, at the other end you can see E. This gives us the key to the brightness of the wrinkle ridges that make up the "X": the relief under the mantle of lava that formed the Mare Nubium is quite high, that is, the lava is very thin. The key is in a wonderful book, “The Modern Moon. A Personal View”, by Charles A. Wood, Sky Publishing, 2003, p.145: “Nubium must be thin because the partial rims of many older craters pro- trude through them. Louisiana Moon mapper René DeHon calculated most of the Nubium lavas are less than 500 meters thick”. That is, Mare Nubium allows us to glimpse what is below it: “When the terminator is near, Mare Nubium appears crossed by a number of wrinkle ridges that form no particular pattern”, as we see in image 4, taken 5 years ago (at colongitude 17.5º), in which our X appears mingled with a lower eleva- tion wrinkle ridges that can be seen with oblique light. Our X marks, then, the highest parts of the ancient relief submerged by the Mare Nubium lava, lava thinner than the lava that flooded other basins. A final cu- riosity: on this wrinkle ridge the LRO probe discovered that “The slope of this ridge is littered with boulders, which have higher reflectance than the surrounding material. Where do these boulders come from? They were likely eroded from the fragmented basalt by seismic events from nearby impacts. The bedrock (mare) was pre-fractured during the formation of the wrinkle ridge; thus, the boulders' size and shape likely represents these small-scale internal fracture patterns. The ridge is still eroding today! New boulders will erode out of the edge of the ridge until there is no more ridge to erode, while the boulders will be turned to dust by bombardment”.

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Figure 4. Mare Nubium, Francisco Alsina Cardinalli, Oro Verde, Argentina. 20 December 2015 00:17 UT. 10 inch Meade LX200 Schmidt-Cassegrain telescope, EOS Digital Rebel ES.

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Size Comparison Between Full Moons Perigee and Apogee in 2020 Victor Hugo Cabrera-Peláez and Diana García-Teyssie

I wish to submit my size comparison between perigee full moon of April 8 at 02:37UTC at a distance of 357,208 km from earth and apogee full moon of October 02 at 00:43 UTC at a distance of 404762.8 km from earth for lunar section of ALPO

In April, 25 individual photographs were taken in RAW format and High Dynamic Range processing in Adobe Camera RAW of Photoshop but in October 20 images were staked instead of being processed in HDR. All images were taken in direct focus with a Sony A7 camera in a 120mm f/8.3 refractor telescope with a 2.5 Barlow lens attached to the camera, in April with ISO 50, time of 1/30s we obtained an image size of 25mm in the sensor, in October with ISO 100, time of 1/25s we obtained an image of only 19.2mm in the sensor.

Observers: Victor Hugo Cabrera-Peláez and Diana García-Teyssier, Astronomical Society of Puebla “Germán Martínez Hidalgo” city of Puebla 19.0144 ° N, -98.2036 ° W, México.

Name of feature: Size Comparison Between Full Moons Perigee and Apogee in 2020. Date and time of observation: April 08 at 02:37 UTC and October 15 at 12:59 UTC Without filter, but focusing with a diffraction mask of my own design. Refractor telescope of 120mm aperture and f/8.3 In both images’ north is at top Seeing of 7 Transparency of 4

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Shadowplay Rik Hill

The big crater just left of center vis (139 km). Notice the dramatic shadows on the floor of this crater as the first rays of sun peek over the eastern wall. On the western wall we see that the crater Klein (46 km) still deep in shadow with the shadow of the central peak of Albategnius just touching its northern wall. The huge crater at the top of the image is Hipparchus (155 km) with (31 km) on the northern side of its floor. Due east of Horrocks (right) is a largely ruined crater, (46 km). Between Hippar- chus and Albategnius is an interesting arch of craters of decreasing size toward the east (eight). The largest is (37 km) followed by Hind (31 km) and the last two are Hipparchus C (17 km) and Hipparchus L (13 km).

East of the arc of craters is a pair of similar sized craters. The leftmost is Lindsay (32 km) while the other slightly larger crater is a satellite crater of a much smaller crater. Just east of Albategnius is a curious crater that appears to have two appendages to the northwest. This is (26 km) with the appendages being shown on LROC QuickMap as several smaller craters merged with Ritchey. This configuration makes for interesting study on a good steady night. Going further east we come to a slightly polygonal crater Andĕl (36 km) and the big one in the lower right corner, (65 km). Notice the tangent to the southern wall of this crater running northwest to southeast.

Albategnius, Richard Hill, Loudon Observatory, Tucson, Arizona, USA. 24 October 2020 02:15 UT, colongitude 359.5o. Dynamax 6 ich Schmidt-Cassegrain telescope, 2x Barlow, 665 nm filter, Skyris 132 M camera. Seeing 8- 9/10.

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Central Ridgets on Heraclitus and Stöfler Alberto Anunziato

To begin to put some order in this area so devastated by meteoritic and cometary impacts, the ancient crater in the center of the image, to the right, is Maurolycus and to its left ... a jumble of craters on top of each oth- er, the bigger one is the Pre-Nectarian Stöfler, which has (strangely) a smooth floor with few impacts across its 126 kilometers in diameter. Overlaid with Stöfler is (which is also Pre-Nectarian) and several secondary craters. Now ... the wall that we see in the center of image 2, which casts a dense shadow and whose upper part is quite bright, to which crater does it belong? Not Stöfler or Faraday, it is surely part of a crater older than Stöfler, which makes this isolated wall the oldest relic in this area. And we will see more of this if we go up to the strange set in the center of the upper part of image 1. The two craters of identical size (77 kilometers diameter) are Licetus (bottom) and Cuvier (top), between them runs Heraclitus from north to south towards Heraclitus D. Heraclitus has the most unusual shape of all . Is it really a crater? That's the question Chuck Wood asks in The Lunar Picture of the Day (LPOD) of April 16, 2005 (http:// www.lpod.org/wiki/April_16,_2005): “Is Heraclitus a crater or merely a collection of arcs that our eye magically connects? I think it is a real feature, but not a normal crater”. At https://www.vofoundation.org/ blog/south-of-heraclitus/ Rick Hill argues that Heraclitus is an unusual north-south elongated feature… the result of a merger of two or three craters”. What characterizes Heraclitus is its central ridge (image 3). Instead of a central peak we have a central ridge, but it could not have been formed on the impact but has a previous origin. Thanks to the LPOD of April 16th 2005 we know that there is another crater that has not one but two central elevations, Schiller, as we can see in this clipping of Plate 374 of the Lunar Orbiter Photographic Atlas of the Moon (image 4). And, as Wood says: “Schiller is also elongated, as Heraclitus may be, judging by its straight northern rim. It is generally believed that Schiller formed by an oblique impact or series of simultaneous impacts. Perhaps that is also the origin of Heraclitus”. It may be, or it may be that we cannot accomplish our detective work and we cannot even reconstruct to which crater the central ridge belongs, just as we cannot know the origin of the central ridge that we see inside Stöfler.

Figure 1, Stöfler and Heraclitus, Alberto Anunziato, 09 October 2016 00:36 UT. Celestron 11 inch Edge HD Schmidt- Cassegrain telescope, QHY5-II camera.

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Figure 2, Stöfler close-up, Alberto Anunziato, 09 October 2016 00:36 UT. Celestron 11 inch Edge HD Schmidt- Cassegrain telescope, QHY5-II camera.

Figure 3, Heraclitus close-up, Alberto Anunziato, 09 October 2016 00:36 UT. Celestron 11 inch Edge HD Schmidt- Cassegrain telescope, QHY5-II camera.

Figure 4, Schiller, Plate 374 Lunar Orbiter Photographic Atlas of the Moon.

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Searching Lunar Domes in Mare Crisium: The Dome Crisium 1 Located Near Cleomedes G (Preliminary Report) Raffaello Lena Lunar domes are the best evidence of volcanic activity in the moon. Most have very low angle of inclina- tions, only a few degrees at most. This makes domes similar to earth's shield volcanoes formed by outpour- ing of magma from a central vent (effusive eruption) [1-3].

Over the past few years only one dome near the Yerkes crater has been identified and studied [3]. Yerkes 1 is characterized by the presence of rilles in the summit. It has a height of 110 ± 20 m, a flank slope of 1.36° ± 0.20°, and a volume of 4.8 km3 (see also our map http://crisiumdomes.blogspot.com/).The Crisium basin is of Nectarian epoch, while the mare material is of the Upper Imbrian epoch [4].

Maximilian Teodorescu, from Romania, has imaged another dome located at coordinates of 23.35°N and 58.37°E. The examined dome-named Crisium 1 (Cr1)- is clearly detectable in the image taken on October 3, 2020 at 23:02 UT (Fig. 1).

Another image of this region made by Pau on the same day, October 3, 2020 but at 15:14 UT is shown in Fig. 2.

Figure 1: Image taken by Teodorescu on October 3, 2020 at 23:02 UT using a 355 mm Newtonian telescope and ASI 174MM camera. The examined lunar dome-termed Cr1- is marked with white lines

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Figure 2: Image taken by Pau on October 3, 2020 at 15:14 UT using a 250 mm f/6 reflector and a QHYCCD290M camera.

Another image of Cr1 was made by Guy Heinen on March 22, 2019 at 23:08 UT (Fig. 3).

Figure 3: Image taken by Heinen on March 22, 2019 at 23:08 UT using a Schmidt Cassegrain 235mm.

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A possible vent of 3.4 km diameter and 160 m deep is present on the summit (see Figs. 1-3 showing the ter- restrial telescopic images and Fig. 4, which displays a WAC image). The image of Fig. 4 is shown in cylin- drical projection, deleting the foreshortening.

Figure 4: LRO WAC imagery. The dome under study is marked with white lines. The image is shown in cylindrical projection, thus deleting the foreshortening. On the summit of Cr1 are present some wrinkle ridges and a possible vent (under investigation).

Morphometric properties: digital elevation map based on telescopic imagery and LOLA DEM

Generating an elevation map of a part of the lunar surface requires its three-dimensional (3D) reconstruc- tion. A well-known image-based method for 3D surface reconstruction is shape from shading (SfS). It makes use of the fact that surface parts inclined towards the light source appear brighter than surface parts inclined away from it. The SfS approach aims for deriving the orientation of the surface at each image loca- tion by using a model of the reflectance properties of the surface and knowledge about the illumination con- ditions, finally leading to an elevation value for each image pixel [3]. The SfS method requires accurate knowledge of the scattering properties of the surface in terms of the bidirectional reflectance distribution function (BRDF).

The height h of a dome is obtained by measuring the altitude difference in the reconstructed 3D profile be- tween the dome summit and the surrounding surface, considering the curvature of the lunar surface. The av- erage flank slope ζ was determined according to: ζ= arctan 2h/D. The uncertainty results in a relative standard error of the dome height h of ±10 percent, which is independent of the height value itself. The dome diameter D can be measured at an accuracy of ± 5 percent. The 3D reconstruction of the dome Cr1 obtained using terrestrial telescopic images is reported in Figs. 5-6.

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Figure 5: 3D reconstruction of Cri1 based on terrestrial telescopic image of Fig. 1 by photoclinometry and SfS analy- sis. The vertical axis is 15 times exaggerated.

Figure 6: 3D reconstruction of Cri1 based on terrestrial CCD image of Fig. 2 by photoclinometry and SfS analysis. The vertical axis is 25 times exaggerated.

The examined dome has a base diameter of 24.5±0.5 km. The height of Cri1 measured on the images shown in Figs. 1 and 2 amounts to 215±20 m and 225±20 m, respectively. Using the image of Fig. 3 the derived height amounts to 230±20 m.

ACT-REACT Quick Map tool was also used to access to the LOLA DEM dataset, obtaining the cross- sectional profile for the examined dome (Fig. 7).

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Figure 7: LRO WAC-derived surface elevation plot of Cr1 based on LOLA DEM in N-S direction.

The most elevated part of the surface section covered by the DEM (in N-S direction) has a height of 220 ± 20 m, thus consistent with the measurements carried out on the telescopic images, yielding an average slope of 0.98° ± 0.1°. The edifice volume is determined, assuming a parabolic shape, to 51 km3.

Spectral data Spectral data have been obtained using Chandrayaan-1 Moon Mineralogy Mapper (M3) an imaging reflec- tance spectrometer that can detect 85 channels between 460 to 3,000 nm. The spectrum of the dome (Fig. 8) displays a narrow trough around 1,000 nm with a minimum wavelength at 975 nm and an absorption band at 2,130 nm, corresponding to a typical High-Ca pyroxene signature, indicating a basaltic composition.

Figure 8: Moon Mineralogy Mapper (M3) spectra of the examined dome. The Clementine UVVIS spectral data reveal a color ratio of R415/R750=0.5713, indicating a low TiO2 con- tent <3%.

Classification According to the classification scheme for lunar domes [3] Cri1 belongs to class C1. It is the second dome identified in Mare Crisium during our survey after Yerkes1 (Fig. 9).

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Figure 9: Image taken by Teodorescu on October 3, 2020 at 23:02 UT using a 355mm Newtonian telescope and ASI 174MM camera. The dome Yerkes 1 is marked with white lines.

Ye1, with its low flank slope and rather low edifice volume, belongs to class B2 [3]. A map of this region including the dome Ye1 is published in our lunar domes atlas (http://crisiumdomes.blogspot.com/). Further analysis is ongoing. We encourage more high-resolution imagery of this area so we can have more data of this dome, which is under study. Please check also your past imagery and send them to me for the ongoing study (lunar- [email protected]).

References [1] Basaltic Volcanism Study Project, 1981. Basaltic Volcanism on the Terrestrial . New York: Pergamon Press. [2] Lena, R., Lunar domes, chapter in Encyclopedia of Lunar Science Editor: Brian Cudnik, 2015, Springer ISBN: 978-3-319-05546-6. [3] Lena, R., Wöhler, C., Phillips, J., Chiocchetta, M.T., 2013. Lunar domes: Properties and Formation Pro- cesses, Springer Praxis Books. [4] Wilhelms, D., The Geologic History of the Moon, USGS Prof. Paper 1348. Washington: GPO, 1987.

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ALPO Banded Craters Program

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ALPO Banded Craters Program

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Focus On: The Lunar 100 Features 31 through 40

Jerry Hubbell Assistant Coordinator, Lunar Topographical Studies

This is the fourth article of ten in a series on Chuck Wood’s Lunar 100 list. Chuck Wood, the founder of the Lunar Photo of the Day (LPOD) (Ref.), first discussed this in a Sky & Telescope article published in 2004, and later published on the Sky & Telescope website (Ref.). This series will run from May 2020 until January 2022. I may insert a few other topics in between this series so the end date for this series may extend out to the end of 2022. Chuck wanted this list of lunar features (L1 to L100) to be like the well- known list of objects that would give lunar observers a way to progress in their study of the moon and become life-long observers. The list contains all the diverse features of the Moon including Mare, Cra- ters, Rilles, Mountains, and Volcanic Domes. The list starts out with the view of the full disk of the Moon and progresses through more difficult features.

This series of Focus On articles is meant to be the basis for a lunar visual observing program but is not lim- ited to that. It can be the basis for starting your own image-based study of the Moon, which will enable you to use the Lunar Terminator Visualization Tool (LTVT) (Ref.), a sophisticated software program used to do topographical measurements of the lunar surface. These articles will introduce and show each of the Lunar 100 features as observed and submitted by our members through drawings, images, and narrative descrip- tions. Although you can use your naked eye and binoculars to start observing objects L1 – L20, observing objects L21 – L80 will require the use of a 3-inch (76-mm) telescope. Features at the end of the list (L81 – L100) will require a 6 to 8-inch (152 to 203-mm) telescope. Many of the features are best observed at differ- ent phases of the Moon.

One of the best ways to help you learn the features of the Moon is through sketching the lunar surface. Dur- ing this series of articles, we will highlight drawings of many of the Lunar 100 features. Springer Books publishes an excellent book, released in 2012, called Sketching the Moon (Handy, et al.) (Ref.). There are other resources on the Internet to help you get started observing and sketching the Moon including the ALPO’s excellent Handbook of the ALPO Training Program (Ref.)

In this article we continue with features 21 through 30 on Chuck’s list. This article highlights the excellent drawings of each of these features submitted by Michel Deconinck from Provence, France. Here is a list of features 21 – 30: L FEATURE NAME SIGNIFICANCE RUKL CHART 31 Taruntius Young floor-fractured crater 37 32 Arago Alpha & Beta Volcanic domes 35 33 Serpentine Ridge Basin inner-ring segment 24 34 Lacus Mortis Strange crater with & ridge 14

35 Triesnecker Rilles Rille family 33 36 Grimaldi basin A small two-ring basin 39

37 Bailly Barely discernible basin 71 38 Sabine and Ritter Possible twin impacts 35 39 Schickard Crater floor with Orientale basin ejecta 62

40 Janssen Rille Rare example of highland rille 67, 68

Table 1. The Fourth Set of 10 Lunar 100 Features

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The Lunar 1 The Lunar 100: Feature 31-Taruntius T • Ta- run • • • • • • • • • • • • • • • • •

Figure 1. Taruntius, Francisco Alsina Cardinalli (Oro Verde, Argentina), 21 August 2016, 05:16 UT, Colongitude 129.4°, 250-mm SCT, QHY5-II camera, IR-pass Filter, North/Up, East/Right.

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The Lunar 100: Feature 32-Arago Alpha & Beta

Figure 2. Arago Alpha & Beta, Alberto Anunziato (Paraná, Argentina), 16 April 2017 03:00-03:25 UT, Colongitude 148.0°, 105 mm. Maksutov-Cassegrain, Magnification 154x, Seeing 7/10, North/Up, East/Right.

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The Lunar 100: Feature 33-The Serpentine Ridge

Figure 3. Serpentine Ridge, David Teske, Louisville, Mississippi, USA, 07 October 2020, 09:28 UT, Colongitude 152.9°, 4-inch f/15 Skylight Refractor, IR block, ZWO ASI120mm/s camera, Seeing 8/10 North/Down, East/Left.

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The Lunar 100: Feature 34–Lacus Mortis

Figure 4. Lacus Mortis, Francisco Alsina Cardinalli (Oro Verde, Argentina), 16 January 2016, 00:45 UT, Colongi- tude 348.5°, 250 mm. Schmidt-Cassegrain, Canon Eos Digital Rebel XS, video camera. North/up, East/left.

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The Lunar 100: Feature 35–Triesnecker Rilles

Figure 5. Lunar Dome Near Triesnecker Rille, Rik Hill, Tucson, AZ, June 13, 2016 0236 UT, 35-cm C14 SCT, Wrat- ten 21 filter, SPC900NC CCD camera, north/up, east/right.

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The Lunar 100: Feature 36-Grimaldi Basin

Figure 6. Grimaldi Basin, David Teske, Louisville, Mississippi, USA, 01 October 2020, 03:44 UT, Colongitude 77.0°, 4-inch f/15 Skylight Refractor, IR block, ZWO ASI120mm/s camera, Seeing 7/10 North/Up, East/Right.

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The Lunar 100: Feature 37-Bailly

Figure 7. Bailly, Fernando Gimenez (Montevideo, Uruguay), 29 August 2012, 00:25 UT, Colongitude 9.4°, 230-mm refractor, BENQ Camera, North/Right, East/Down

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The Lunar 100: Feature 38-Sabine and Ritter

Figure 8. Sabine & Ritter, David Teske, Louisville, Mississippi, USA, 07 October 2020, 09:34 UT, Colongitude 153.0°, 4-inch f/15 Skylight Refractor, 1.5 x barlow, IR block, ZWO ASI120mm/s camera, Seeing 8/10 North/Up, East/Right.

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The Lunar 100: Feature 39-Schickard

Figure 9. Schickard, Jerry Hubbell, Locust Grove, VA, 07 January 2012 00:37 UT, Colongitude 67.8°, 120 mm f/7.5 Refractor, ATIK 314e CCD camera. Seeing 7/10, Transparency 5/6, North/Up, East/Right.

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The Lunar 100: Feature 40-Janssen Rille

Figure 10. Janssen, David Teske, Louisville, Mississippi, USA, 04 October 2020, 06:58 UT, Colongitude 115.1°, 4- inch f/15 Skylight Refractor, IR block, ZWO ASI120mm/s camera, Seeing 7/10 North/Up, East/Right.

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This month we had a fair response to our request for images and drawings for the fourth set of 10 features of the Lunar 100 (L31 – L40). I am grateful for all the submissions we received. We had a total of 40 images and drawings submitted to the TLO from 12 astronomers. Most of the images came from Alberto Anun- ziato’s groups, SAO-SLA, and LIADA. Early on he prefaced the images he sent on behalf of his group this way:

“LUNAR 100 PROGRAM Sociedad Astronómica Octante-Sociedad Lunar Argentina

When we found out that the next objectives of the Focus On Section would be the features listed in the Charles Wood's famous Lunar 100, the members from Sociedad Lunar Argenti- na (SLA) and Sociedad Astronómica Octante (SAO) of the República Oriental del Uruguay, we considered interesting to join the initiative of "The Lunar Observer" (TLO) and therefore we launched our Lunar 100 Program, under the auspices of the Lunar Section of the Liga Iberoamericana de Astronomía (LIADA). The objective is twofold. We will report the imag- es submitted to the program to "The Lunar Observer". And we will also publish them in all the media of SLA, SAO and LIADA. We think it is a great opportunity to stimulate amateur and if the call is successful, we can dream of some final joint publica- tion.”

We look forward to future drawings and images submitted by ALPO, SLA, SAO, LIADA members and others from across the world. Please share with us any images you have in your image catalog; we hope to see everyone participate in these Focus On articles.

– Jerry Hubbell

COMPUTER PROGRAMS

Virtual Moon Atlas https://sourceforge.net/projects/virtualmoon/

Lunar Terminator Visualization Tool (LTVT) http://www.alpoastronomy.org/lunarupload/LTVT/ ltvt_20180429-HTML.zip

REFERENCES

Chuck Wood, The Lunar 100 (November 2012), Sky & Telescope Magazine (website), https:// skyandtelescope.org/observing/celestial-objects-to-watch/the-lunar-100/ (retrieved April 26, 2020)

Handy R., Kelleghan D., McCague Th., Rix E., S., Sketching the Moon, 2012 Springer Books, https://www.springer.com/us/book/9781461409403 (retrieved April 26, 2020)

Association of Lunar and Planetary Observers, Handbook of the ALPO Training Program, http:// www.cometman.net/alpo/ (retrieved April 26, 2020)

Chuck Wood, Lunar Photo Of the Day (LPOD), https://www2.lpod.org/wiki/LPOD:About (retrieved April 26, 2020)

Lunar Reconnaissance Office ACT-REACT Quick Map, http://target.lroc.asu.edu/q3/ (retrieved October 31, 2017)

The Lunar Observer/November 2020/ 51

Patrick Chevalley, Christian Legrand, Virtual Moon Atlas, http://ap-i.net/avl/en/start (retrieved June 30, 2018)

International Astronomical Union Gazetteer of , Crater Tycho, https://planetarynames.wr.usgs.gov/Feature/6163 (retrieved March 1, 2020)

Wikipedia, The Lunar 100 , https://en.wikipedia.org/wiki/Lunar_100 (retrieved April 26, 2020)

Aeronautical Chart Information Center (ACIC), United States Air Force, LAC Series Chart Reference, host- ed by the Lunar and Planetary Institute, https://www.lpi.usra.edu/resources/mapcatalog/LAC/ lac_reference.pdf (retrieved September 1, 2019)

Lunar and Planetary Institute, Digital Lunar Orbiter Photographic Atlas of the Moon, http:// www.lpi.usra.edu/resources/lunar_orbiter/ (retrieved September 1, 2017).

ADDITIONAL READING

Bussey, Ben & . 2004. The Clementine Atlas of the Moon. Cambridge University Press, New York.

Byrne, Charles. 2005. Lunar Orbiter Photographic Atlas of the . Springer-Verlag, London.

Chong, S.M., Albert C.H. Lim, & P.S. Ang. 2002. Photographic Atlas of the Moon. Cambridge University Press, New York.

Chu, Alan, Wolfgang Paech, Mario Wigand & Storm Dunlop. 2012. The Cambridge Photographic Moon Atlas. Cambridge University Press, New York.

Cocks, E.E. & J.C. Cocks. 1995. Who’s Who on the Moon: A biographical Dictionary of Lunar Nomencla- ture. Tudor Publishers, Greensboro

Gillis, Jeffrey J. ed. 2004. Digital Lunar Orbiter Photographic Atlas of the Moon. Lunar & Planetary Insti- tute, Houston. Contribution #1205 (DVD). (http://www.lpi.usra.edu/resources/lunar_orbiter/).

Grego, Peter. 2005. The Moon and How to Observe It. Springer-Verlag, London.

IAU/USGS/NASA. Gazetteer of Planetary Nomenclature. (http://planetarynames.wr.usgs.gov/Page/MOON/ target).

North, Gerald. 2000. Observing the Moon, Cambridge University Press, Cambridge.

Rukl, Antonin. 2004. Atlas of the Moon, revised updated edition, ed. Gary Seronik, Sky Publishing Corp., Cambridge.

Schultz, Peter. 1972. Moon Morphology. University of Texas Press, Austin. The-Moon Wiki. http://the- moon.wikispaces.com/Introduction

Wlasuk, Peter. 2000. Observing the Moon. Springer-Verlag, London.

Wood, Charles. 2003. The Moon: A Personal View. Sky Publishing Corp. Cambridge.

Wood, Charles & Maurice . 2012. 21st Century Atlas of the Moon. Lunar Publishing, UIAI Inc., Wheeling.

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Recent Topographic Studies Additional Images of Focus on Number 31 Taruntius and Number 32 Arago Alpha and Beta

Taruntius, Desiré Godoy, Oro Verde, Argentina, SLA. 28 Au- gust 2020 23:53 UT. 200 mm re- fractor tele- scope, 742 nm filter, QHY5-II camera.

Arago, Jay Albert, Lake Worth, Florida, USA. 05 Octo- ber 2019 00:45 UT. Celestron NexStar Evolution 8 inch Schmidt-Cassegrain telescope, iPhone 6S camera, 7 mm orthoscopic eyepiece, Photoshop Elements. North is to the upper right. Seeing 7/10, transparency 2/6.

Jay writes: Arago crater with volcanic domes alpha and beta are at the lower left of the frame. I under- stand from Raffaello Lena that this photo also shows two “bisected” volcanic domes just to the left of .

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Recent Topographic Studies Additional Images of Focus on Number 32 Arago Alpha and Beta Arago and Robert H. Hays, Jr.

I observed the area around these craters on the evening of May 22/23, 2007. These craters lie in southwest- ern , and were fairly near to the center of the visible disk that night due to longitude li- bration. Arago shows some evidence of terracing inside its west rim, and an odd strip of shadow near its north end. The shadow of its northwest rim also appears detached. Two ridges protrude from the south rim of Arago giving the appearance of horns. Manners is southwest of Arago, and cast a pronounced shadow with its west rim, but its overall shadowing was more symmetrical than that of Arago. Arago D is the pit northeast of Arago, and Arago E is the larger crater north of D. There are several wrinkles running approxi- mately north-south near Arago D and E, and more wrinkling and a low ridge southeast of Arago. This low ridge may be associated with the ghost ring . Of particular interest are nearby domes. Arago alpha is the large dome north of Arago. This dome is nearly round, but it has a blunt corner toward the northwest. There appears to be a smaller dome west of Arago alpha, and a very low dome to the north. This feature is not much smaller than alpha, but its shading was very subtle. It may be too conspicuous on the sketch. These two domes both appeared elongated northwest-southeast. Arago beta is west of Arago and north of Manners. It is smaller than alpha, and about the size of the vey low dome to the north. Arago beta appears slightly elongated east-west, and at times, I could glimpse what may be a summit craterlet. (I could not do that with alpha.)

Arago & Manners, Robert Hays, Jr., Worth, Illinois, USA. 23 May 2007 01:48-02:16 UT. 15 cm reflector telescope, 170 x. See- ing 8/10, transparency 6/6. This originally appeared in the October 2007 The Lunar Observer.

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Recent Topographic Studies Additional Images of Focus on Number 32 Arago Alpha and Beta

Arago Alpha, Alber- to Anunziato, Para- ná, Argentina. 16 April 2017 04:20– 04:40 UT. Meade EX 105 Maksutov- Cassegrain telescope, 154 x. Seeing 7/10.

Arago, Sergio Babino, Montevideo, Uruguay. 07 April 2019 00:58 UT. 203 mm catadrioptic telescope, ZWO ASI 174 mm camera.

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Recent Topographic Studies Additional Images of Focus on Number 32 Arago Alpha and Beta Additional Images of Focus on Number 33 the Serpentine Ridge

Arago Beta, Alberto Anunziato, Paraná, Ar- gentina. 16 April 2017 05:00–05:25 UT. Meade EX 105 Mak- sutov-Cassegrain tele- scope, 154 x. Seeing 7/10.

Serpentine Ridge, Francisco Alsina Cardinalli, Oro Verde, Argentina. 28 March 2016 04:45 UT. 11 inch Celestron Edge HD Schmidt- Cassegrain telescope, EOS Digital Rebel ES.

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Recent Topographic Studies Additional Images of Focus on Number 33 the Serpentine Ridge

Serpentine Ridge, Francisco Alsina Cardinalli, Oro Verde, Argentina. 14 May 2016 02:32 UT. 10 inch Meade LX200 Schmidt-Cassegrain tele- scope, Astronomik ProPlanet 742 IR-pass, QHY5- II camera.

Serpentine Ridge, Pedro Romano, San Juan, Argen- tina. 19 June 2019 23:30 UT. 500 mm reflector tel- escope, ZWO ASI 120 camera.

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Recent Topographic Studies Additional Images of Focus on Number 33 the Serpentine Ridge

Serpentine Ridge, Francisco Alsina Cardinalli, Oro Verde, Ar- gentina. 14 May 2016 02:37 UT. 10 inch Meade LX200 Schmidt-Cassegrain telescope, Astronomik ProPlanet 742 IR- pass, QHY5-II camera.

Serpentine Ridge, Sergio Babino, Monte- video, Uruguay. 14 March 2020 04:58 UT. 203 mm catadrioptic telescope, ZWO ASI 174 mm camera.

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Recent Topographic Studies Additional Images of Focus on Number 34 Lacus Mortis

Lacus Mortis, Juan Manuel Biagi, Oro Verde, Argentina. 27 March 2016 04:25 UT. 11 inch Celestron Edge HD Schmidt-Cassegrain telescope, EOS Digital Rebel ES.

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Recent Topographic Studies Additional Images of Focus on Number 34 Lacus Mortis

Lacus Mortis, Francisco Alsina Cardinalli, Oro Verde, Argentina. 27 March 2016 04:45 UT. 11 inch Celestron Edge HD Schmidt-Cassegrain telescope, EOS Digital Rebel ES.

Lacus Mortis and Saturn, Sergio Babino, Montevi- deo, Uruguay. 19 June 2019 02:27 UT. 8”Astrotech RC (Ritchety Chretien) telescope, ZWO ASI 174 mm camera.

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Recent Topographic Studies Additional Images of Focus on Number 35 Triesnecker Rilles

Triesnecker, Jay Albert, Lake Worth, Florida, USA. 18 February 2013 23:40 UT. Celestron 11 inch Schmidt-Cassegrain telescope, Celestron Neximage 5 solar system camera, Registax and Photoshop Ele- ments. North is up. Seeing 8/10, transparency 4.5/6.

Triesnecker, Francisco Alsina Cardinalli, Oro Verde, Argentina. 01 July 2017 23:26 UT. 200 mm refractor telescope, QHY5-II camera.

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Recent Topographic Studies Additional Images of Focus on Number 35 Triesnecker Rilles Triesnecker Robert H. Hays, Jr.

I sketched this crater and vicinity on the evening of February 5/6, 2006 shortly before the Moon hid 9 Tauri. This crater is in near the center of the visible disk. It is a fairly simple round crater with some evidence of interior terracing. There are also some high points on its southwest and northwest rims. The small pits Triesnecker H and J lie to the southwest, and there is a variety of peaks, ridges and wrinkling nearby. Some of these features may form a ghost ring adjacent to Triesnecker’s south rim. The most nota- ble nearby features are the group of rilles just east of Triesnecker. There is a focal point where five of them converge near the pit Triesnecker F. A straight rille extends southward from this junction, and a meandering rille is a short distance to the east. The Lunar Quadrant map labels these as Triesnecker V and I, respective- ly. A short rille connects these two. The rille Triesnecker II extends northeastward from the junction to- ward the crater A. This rille is fairly straight except for a kink about halfway along its length. It crosses the rille Triesnecker II near Hyginus A. Rille II is straight on either side of this junction, but III bends noticeably there. Triesnecker VII extends northward from the five-way junction, but this rille soon bends to become roughly parallel to rille II. A very narrow rille covers the short distance between the main junction and Triesnecker.

Triesnecker, Robert Hays, Jr., Worth, Illinois, USA. 06 February 2006 02:35-03:07 UT. 15 cm reflector telescope, 170 x. See- ing 8/10, transparency 6/6.

This originally appeared in the June 2006 The Lunar Observer.

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Recent Topographic Studies Additional Images of Focus on Number 35 Triesnecker Rilles

Triesnecker, Francisco Alsi- na Cardinalli, Oro Verde, Ar- gentina. 01 July 2017 23:34 UT. 200 mm refrac- tor telescope, QHY5-II cam- era.

Triesnecker, Francisco Alsina Cardi- nalli, Oro Verde, Argen- tina. 01 July 2017 23:37 UT. 200 mm refractor tele- scope, As- tronomik Pro- 742 IR- pass filter, QHY5-II cam- era.

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Recent Topographic Studies Additional Images of Focus on Number 36 Grimaldi Basin

Grimaldi, Francisco Alsina Cardinalli, Oro Verde, Argen- tina. 30 April 2016 08:57 UT. 10 inch Meade LX200 Schmidt -Cassegrain telescope, QHY5- II camera.

Grimaldi, Sergio Babino, Montevideo, Uruguay. 20 January 2019 04:20 UT. 8”Astrotech RC (Ritchety Chretien) telescope, ZWO ASI 174 mm camera.

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Recent Topographic Studies Additional Images of Focus on Number 36 Grimaldi Basin

Grimaldi, Francisco Alsina Car- dinalli, Oro Verde, Argentina. 06 March 2016 07:46 UT. 10 inch Meade LX200 Schmidt- Cassegrain telescope, Canon EOS Digital Rebel XS camera.

Grimaldi, Sergio Babino, Montevideo, Uruguay. 08 March 2020 01:34 UT. 203 mm catadrioptic tele- scope, ZWO ASI 174 mm camera.

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Recent Topographic Studies Additional Images of Focus on Number 36 Grimaldi Basin

Grimaldi, Juan Manuel Biagi, Oro Verde, Argentina. 24 February 2014 06:14 UT. 10 inch Meade LX200 Schmidt- Cassegrain telescope, Webcam Phillips SPC900NC.

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Recent Topographic Studies Additional Images of Focus on Number 38 Sabine and Ritter

Ritter, Sabine, Schmidt and Dionysius Robert H. Hays, Jr.

I observed this area in southwest Mare Tranquillitatis on the evening of December 30 and 31, 2003. The seeing was mediocre, and I used a lower magnification than usual, but this is a varied group of craters, so I decided that they were worth a sketch. Sabine and Ritter are the two largest craters in this area. Sabine is very symmetrical and regular except for a small peak on its south rim. Ritter has a slightly flattened east rim, and showed more interior shadow at this time. Sabine also has a rim that appears more raised than that of Ritter. Ritter C and B are fair-sized craters northwest of Ritter, and Ritter D is the smaller crater north- west of Ritter B. Sabine and Ritter have the same tint as Mare Tranquillitatis, and Ritter C, B and D proba- bly do also. The crisp crater south of Ritter is Schmidt. This crater has a bright interior. The small crater north of Sabine is Arago B, according to the Lunar Quadrant map; its interior also looked relatively bright. The edge of Mare Tranquillitatis is fairly well-defined west of Schmidt and Ritter. Dionysius is the conspic- uous crater just outside the mare. This crater has a very bright interior, and also has a halo. It is bright at full moon, and is a good target for crater timings. I did note several hills near Dionysius, but more detain may have been noticed if the seeing were better. Probably for that reason, I did not see any of the rilles that the map shows in that area.

Ritter, Sabine, Schmidt and Dionysius, Robert Hays, Jr., Worth, Illinois, USA. 31 December 2003 01:18-01:40 UT. 15 cm re- flector telescope, 116 x. Seeing 5/10, transparency 6/6. This originally appeared in the June 2004 The Lunar Observer.

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Recent Topographic Studies Additional Images of Focus on Number 38 Sabine and Ritter

Sabine and Ritter, Sergio Babino, Montevi- deo, Uruguay. 15 December 2018 00:548 UT. 8”Astrotech RC (Ritchety Chretien) telescope, ZWO ASI 174 mm camera.

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Recent Topographic Studies Additional Images of Focus on Number 38 Sabine and Ritter

Sabine and Ritter, Francisco Alsina Cardinalli, Oro Verde, Argentina. 21 August 2016 04:21 UT. 10 inch Meade LX200 Schmidt-Cassegrain telescope, Astronomik ProPlanet 742 IR-pass filter, QHY5-II camera.

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Recent Topographic Studies Additional Images of Focus on Number 39 Schickard

Schickard, Francisco Alsina Cardinalli, Oro Verde, Argen- tina. 21 August 2016 04:52 UT. 10 inch Meade LX200 Schmidt-Cassegrain telescope, Astronomik ProPlanet 742 IR- pass filter, QHY5-II camera.

Schickard, Martín Queirolo Gomez, Montevideo, Uruguay, SAO . 22 January 2016 23:32 UT. 114 mm Newtonian reflector telescope, Nikon D5100 camera.

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Recent Topographic Studies Additional Images of Focus on Number 39 Schickard

Schickard, Jay Albert, Lake Worth, Florida, USA. 19 August 2013 24:13 UT. Celestron 11 inch Schmidt-Cassegrain telescope, Celestron Neximage 5 solar system camera, Registax and Photoshop Elements. North is up. Seeing 7/10, transparency 3/6, partly cloudy skies.

Schickard, Alberto Anunziato, Paraná, Ar- gentina. 26 August 2018 03:40 UT. Celes- tron CPC1100 11 inch Schmidt-Cassegrain telescope, ZWO ASI 120mm/s camera.

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Recent Topographic Studies Additional Images of Focus on Number 40 Janssen Rille

Janssen, Francisco Alsina Cardinalli, Oro Verde, Argentina. 29 November 2015 05:33 UT. 10 inch Meade LX200 Schmidt- Cassegrain telescope, Canon EOS Digital Rebel XS camera.

Janssen, Marcelo Mojica Gundlach, Cochabamba, Bolivia. 07 July 2019 23:30 UT. 150 mm refractor tele- scope, ZWO ASI 120 cam- era.

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Recent Topographic Studies

21 and 22 Day Old Moon, Jerry Hub- , Wilderness, Virginia, USA. Details on the image.

Jerry writes:

Here are my latest images of the full disk of the moon using the default optical/camera configuration at the Mark Slade Remote Observatory. This configuration is far from opti- mal for high-resolution lunar imag- ing, but I like to see what perfor- mance I can squeeze out of the sys- tem just using my skills and knowledge. This constraint helps me improve my processing skills using Astrostakkert, Registax, and other programs. I think the images turn out very well based on a a plate scale of about 0.9 arcsec/px and an aperture of 165-mm. Craters down to 5-km can be easily discerned, and others down to 3-km can be detected de- pending on the local lighting. I have combined the images into one plate. I have done several others in this series and would love to be able to create a basic full disk atlas for each day at some point. I think I might process what I have to point out the location of as many of the Lunar 100 objects that are near the terminator.

The Lunar Observer/November 2020/ 73

Recent Topographic Studies

Full Moon, Jairo Chavez, Popayán, Colombia. 02 October 2020 02:26 UT. 114 mm refractor telescope, MOTO E5 PLAY.

Bessel, Román García Verdier, Paraná, Argentina. 26 September 2020 23:57 UT. 180 mm Newtonian reflector tele- scope, QHY5-II camera.

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Recent Topographic Studies

Alphonsus, Román García Verdier, Paraná, Argentina. 26 September 2020 23:59 UT. 180 mm Newtonian reflector tele- scope, QHY5-II camera.

Copernicus, Alberto Anun- ziato, Paraná, Argentina. 27 September 2020 00:04 UT. 180 mm Newtonian reflector tele- scope, QHY5-II camera.

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Recent Topographic Studies

Plato, Alberto Anunziato, Paraná, Ar- gentina. 27 September 2020 00:06 UT. 180 mm Newtonian reflector tele- scope, QHY5- II camera.

Plato, Pedro Ro- mano, San Juan, Argentina. 27 September 2020 23:30 UT. 102 mm Maksutov- Cassegrain tele- scope, ZWO ASI 120 camera.

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Recent Topographic Studies

Copernicus, Fernando Surà, San Nicolás de los Arroyos, Ar- gentina. 28 April 2020 22:12 UT. 127 mm Maksutov- Cassegrain tele- scope, CPL Sbony filter, Celestron Nexi- mage 5 camera.

Proclus, Leandro Sid, AEA, Oro Verde, Ar- gentina. 26 October 2020 23:29 UT. 1250 mm x 90 mm Meade Star- Navigator

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Recent Topographic Studies

Stevinus, Román García Verdier, Paraná, Argentina. 27 September 2020 00:02 UT. 180 mm Newtonian reflec- tor telescope, QHY5-II camera.

Copernicus, Ped- ro Romano, San Juan, Argentina. 27 September 2020 23:33 UT. 102 mm Maksutov -Cassegrain tele- scope, ZWO ASI 120 camera.

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Recent Topographic Studies

Copernicus, Pedro Roma- no, San Juan, Argentina. 27 September 2020 23:32 UT. 102 mm Maksutov- Cassegrain telescope, ZWO ASI 120 camera.

Sinus Aestuum, Raf- faello Lena, Rome, Italy. 25 October 2020 20:44 UT. 180 mm Maksutov- Cassegrain telescope.

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Recent Topographic Studies

Copernicus, Leandro Sid, AEA, Oro Verde, Argentina. 26 Oc- tober 2020 23:25 UT. 1250 mm x 90 mm Meade StarNavigator NG 90 Maksutov-Cassegrain telescope, Samsung Galaxy J7 Prime 2 camera.

Waxing Gibbous Moon, Leandro Sid, AEA, Oro Verde, Argen- tina. 27 October 2020 00:03 UT. 1250 mm x 90 mm Meade StarNavi- gator NG 90 Maksutov- Cassegrain telescope, Samsung Galaxy J7 Prime 2 camera.

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Recent Topographic Studies

Tycho, Pedro Romano, San Juan, Argentina. 27 September 2020 23:35 UT. 102 mm Maksutov- Cassegrain telescope, ZWO ASI 120 camera.

Stadius and Eratosthenes, Raf- faello Lena, Rome, Italy. 25 Oc- tober 2020 21:18 UT. 180 mm Maksutov-Cassegrain telescope.

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Lunar Geologic Change Detection Program Coordinator Dr. Anthony Cook- [email protected] Assistant Coordinator David O. Darling [email protected]

2020 November Introduction: In the set of observations received in the past month, these have been divided into three sections: Level 1 is a confirmation of observation received for the month in question. Every observer will have all the features observed listed here in one paragraph. Level 2 will be the display of the most rele- vant image/sketch, or a quote from a report, from each observer, but only if the date/UT corresponds to: similar illumination (±0.5º), similar illumination and topocentric libration report (±1.0º) for a past LTP re- port, or a Lunar Schedule website request. A brief description will be given of why the observation was made, but no assessment done – that will be up to the reader. Level 3 will highlight reports, using in-depth analysis, which specifically help to explain a past LTP, and may (when time permits) utilize archive repeat illumination material.

LTP reports: No Additional LTP reports have been received for September. Concerning Leandro Sid’s (AEA) image of Proclus, Römer, and , from 2020 Sep 23 UT 01:18, men- tioned in the last newsletter (p56), Leandro added that he could indeed also observe the colors visually at the eyepiece, at high magnification, but with the exception that the color pattern oscillated between yellow and pink. But the most significant thing was that the visual effect disappeared after UT 0118, using the same equipment on the same night. I think that I will change the weight of this report to 1, although I sus- pect some atmospheric effect may still be the most likely explanation. On 2020 Jul 24 two impact flashes were recorded just a minute apart. seen by BAA member Luigi Morrone (See Fig 1) – they were also rec- orded by two other UAI members. Statistically the impacts maybe from the same meteor stream, and Lu- narscan software suggests that it may be from the Piscis Austrinids?

Figure 1. Im- pact flash images in earthshine on 2020 Jul 24 as imaged/videoed by Luigi Morrone (BAA) (Left) 19:55:07UT. (Right) 19:56:25 UT.

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News: On October 2nd I took part in my first ALPO ALCON conference (on-line) and gave a talk on LTP statistics. If you are interested there is a youtube video that you can watch – scroll forwards to 3h25m. However, there were also a good couple of lunar lectures before mine that you might want to watch too!

On Monday 26th October NASA held a press conference to announce the discovery of molecular water on the dayside of the Moon. Previously it had been assumed that any dayside water could only sur- vive as OH in minerals on the surface. However, these latest SOPFIA NASA Stratospheric Airborne Obser- vatory, infrared observations suggest (according to one theory) that it may be held in the glass from impact melts from micrometeoroids. The amount is very small, at maximum 400 parts per million by volume. How this relates to LTP it is too early to say – if some LTP are caused by outgassing then one would expect some water to be present, but not locked up in glass. However, many hundreds-thousands of hours SOPHIA observing maybe necessary to confirm this.

Finally, An image in the last newsletter of , that I attributed to Valerio Fontani, was actu- ally taken by Vincenzo della Vecchia.

Level 1 – All Reports received for September: Jay Albert (Lake Worth, FL, USA - ALPO) ob- served: , , Mare Crisium, the Moon’s conjunction with Mars, Plato, Proclus and Vallis Schroteri. Alberto Anunziato (Argentina - SLA) observed: Aristarchus, , , and Pytheas. Anthony Cook (Newtown, UK – ALPO/BAA/NAS) imaged several features. Daryl Dobbs (UK - BAA) observed: Atlas and . Les Fry (UK – NAS) imaged: Anaxagoras, , , Copernicus, , , , Mee, and Sinus Iridum. Leandro Sid (Argentina - AEA) imaged sev- eral features. Román García Verdier (Argentina – SLA) imaged Alphonsus. Fabio Verza (Italy – UAI) im- aged: and Lichtenburg.

Level 2 – Example Observations Received :

Alphonsus: On 2020 Sep 27 UT 23:59 Román García Verdier (Argentina – SLA) imaged this crater under similar illumination to the following report:

Alphonsus 1958 Dec 19 UT 20:00? Observed by Wilkins (Kent, England) described in the NASA catalog as: "Reddish patch on central peak" 15" reflector used. NASA catalog weight=4. NASA catalog LTP ID No. 711. ALPO/BAA weight=3.

Figure 2. Alphonsus as imaged in monochrome, by Román García Verdier (SLA) on 2020 Sep 27 UT 23:59 and ori- entated with north towards the top.

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Fig 2 provides a useful context image as to the appearance of the crater that Wilkins would have seen if it was in a normal state of appearance. Román used an 18cm Newtonian and a QHY5-II camera.

Level 3 - In Depth Analysis:

Geminus: On 2020 Sep 04/05 UT 21:49, 22:38, 22:40, 23:02 Fabio Verza (UAI) imaged in the near IR, and at 00:17 Tony Cook imaged this region using a color webcam, after the following Lunar Schedule re- quest:

BAA Request: On 2011 Jan 21 Nigel Longshaw suspected the eastern side of Geminus (on the border of the crater filled shadow and the eastern illuminated rim) had a coloration to it. This extended for a short dis- tance from the floor shadow into the illuminated rim width and spanned from the north to the south of the crater. For a comparison, Cleomedes was checked but nothing unusual was noticed in its shadow. The ob- server notes that also saw color here too. It’s probable that some natural surface coloration was ob- served, but this needs to be checked out? of aperture 4" or larger are needed to observe this ef- fect. If you have a refractor, then try using this, otherwise a reflector will do just as well. Please send any sketches, images, or visual descriptions to: a t c @ a b e r . a c. u k .

Figure 3. Geminus orientated with north towards the top. (Far Left) A sketch by Nigel Longshaw (BAA) made on 2013 Dec 19 UT 22:15-22:30 (Col. = 118.5°-118.6°, Altʘ=4.7°-4.6°). (Left) A near-IR monochrome image by Fabio Verza (UAI) made on 2020 Sep 04 UT 21:49 (Col. = 118.9°, Altʘ = 4.5°). (Center) A sketch by Nigel Longshaw (BAA) made on 2011 Jan 21 UT 22:30 (Col. = 118.8°, Altʘ = 4.2°). (Right) A color webcam image by Tony Cook taken on 2020 Sep 05 UT 00:17 (Col. = 120.2°, Altʘ = 3.4°) – color saturation at 50%. (Far Right) the same image but cred and blue color channels offset to remove the effects of atmospheric spectral dispersion.

Nigel’s two reports (Fig 3 – Left and Center) of color in Geminus have always fascinated me, and there is an earlier account of a sepia color by Elger from 1885 Sep 29 21:30-22:15, however it is described as being in the surrounds, and the colongitude was much earlier at 113.6°-114.0°. Although Fabio’s image (Fig 3 Left) was in monochrome, it does show the reliability of detail the depiction in Nigel’s sketch (Fig 3 – Far Left) from 2013. My own image (Fig 3 – Right), taken later in colongitude, even after that of Nigel’s 2011 Jan 21 sketch, does show some between the interior shadow and the illuminated eastern rim. I know this was atmospheric spectral dispersion as it appears on similar contrast craters elsewhere, and when I at- tempted to remove it, as in Fig 3 (Far Right) it has mostly vanished. The Moon’s altitude back in the 2011 sketch was 26°, where as in 2013 and 2020 for myself it was around 33°. So, this raises the possibility that what Nigel saw was perhaps induced by our atmosphere? If so then it should be stronger at lower altitudes, and indeed it may well be. The odd thing was that Nigel did not report similar color on other features. We shall leave the weight as it is at the moment to encourage more observing.

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Pytheas: On 2020 Sep 26 UT 00:05 Alberto Anunziato (SLA) imaged the Moon under similar illumination to the following report: On 1982 Aug 29 at UT 02:13-02:30 Robotham (Springfield, ON, Canada, x97 and x160) found that the west rim of Pytheas crater was very bright, especially at lower magni- fications, being one of the brightest spots on the Moon. The Cameron 2006 catalog ID=182 and weight=3. ALPO/BAA weight=1.

Figure 4. Pytheas as indicated by arrows as imaged by Alberto Anunziato on 2020 Sep 27 UT 00:05. North is to- wards the top. Alberto’s image (Fig 4) certainly shows Pytheas to be bright as it has a digital number value of 212.Only the brightest features on the right-hand side of the image exceed this. Pytheas however is on a dark back- ground that gives it more contrast, so may seem the brightest feature. We discussed a similar repeat illumi- nation before for this crater in the 2019 Jan newsletter. P35. I will lower the weight to 0 and remove it from the ALPO/BAA LTP database.

Plato: On 2020 Sep 27 UT 01:20-01:40 Jay Albert (ALPO) observed this crater under similar illumination to one of his earlier LTP reports:

On 2009 Apr 05 at UT 01:03-01:31, 01:44 and 02:30 J. Albert (FL, USA, 11" reflector, x224 and x311, transparency 4-3 and seeing 5-6/10) noted a tiny point on the south east rim of Plato, adjacent to the east wall shadow. It was first seen at x311 without filters, then in both Wratten 25 (red) and Wratten 38A (blue) - it was faintest in the latter. The spot was probably a high point on the south east rim. By 01:28UT the spot was no longer visible in the blue filter, but could still be seen well in red and white light. No change was seen during rechecks at 01:44 or 02:30. The observer con- siders that this was not a LTP as it was on the limits of detectability and anyway ob- serving conditions were poor. The ALPO/BAA weight=1.

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Jay was using 8” SCT and his transparency was initially 1st magnitude and the seeing was 6-7/10. No fil- ters were used. This time around he found the tiny, bright point on the SE wall adjacent to the E wall shad- ow was seen with some difficulty – due to the hazy sky conditions, but was not especially bright anyway. The central craterlet was seen and the N pair were seen with difficulty. Transparency was decreasing and dew was starting to form on the eyepiece towards the end of the observation. We covered this repeat illumi- nation earlier in the 2020 September newsletter, p117, when we assigned it a weight of 0 as normal appear- ance. I will double check that this has been removed from the predictions – sometimes it takes a month or two for the removal to make it into the web pages. But anyway, it is good to have an additional observation to be sure that the LTP was not an LTP.

Atlas: On 2020 Sep 27 UT 20:30-20:58 Daryl Dobbs (BAA) sketched this crater under similar illumination and topocentric libration to the following report:

On 1991 Apr 25 at UT 02:34-02:37 UT D. Darling (Sun Praire, WI, USA, 12.5" reflector, x64) found that Atlas had spots in it that were "more intense in blue". No blinks were detected elsewhere on the Moon apart from Gassendi. The Cameron 2006 catalog ID=425 and weight=4. The ALPO/BAA weight=2.

Figure 5. Atlas as sketched by Daryl Dobbs (BAA) on 2020 Sep 27 UT 20:30-20:58. Orientated with north towards the bottom.

Daryl’s sketch (Fig 5) was made using a 10” Newtonian under II-III seeing. He com- ments that ”the interior of the crater had three dark features, the darkest on South East part under the crater wall, there were two other dark features one on the North East part and one on the North West part. The NE feature was slightly darker than the NW feature. Between these were a bright spot which gave the impression of a 'causeway leading to the center area.” He observed the area using a Red #23a filter fol- lowed by the Blue 80a filter. The contrast between these two filters did give the impression that the albedo features using the Blue filter had a deeper tone than observed in the Red.

Daryl then tried the following filters in sequence: #23a, #12, #58 and finally #80a, then swapped eyepieces and repeated. He gained the impression that the red filter made the area appear darker (including the albedo features) than the blue filter, which made them stand out for from the general area. “The yellow filter did not enhance or diminish the contrast between the albedo features and the surrounding area. The green filter did darken the view through the eyepiece but not so much as the red filter. The glare from the lunar surface was reduced slightly using the blue filter but far more so using the red filter. The slight reduc- tion in the glare with the blue filter could give the impression the albedo features were intense than with the red filter, this theory seems plausible when I used the green and yellow filters as a comparison.”

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To sum up, he thought that the intensity of the spots observed was more to do with reducing the glare from the lunar surface than any change. The contrast of the spots did seem to be enhanced when using the blue filter which he thought was more to do with the geology of the features than any LTP change.

We have covered a repeat illumination report of this crater back in the 2014 March newsletter on p14 and comparing the observations, I think that I will lower the weight to 1 – just enough to keep it on the system as I would like to get hold of some color images just to confirm these visual reports.

General Information: For repeat illumination (and a few repeat libration) observations for the coming month - these can be found on the following web site: http://users.aber.ac.uk/atc/ lunar_schedule.htm . By re-observing and submitting your observations, only this way can we fully resolve past observational puzzles. To keep yourself busy on cloudy nights, why not try “Spot the Difference” be- tween spacecraft imagery taken on different dates? This can be found on: http://users.aber.ac.uk/atc/tlp/ spot_the_difference.htm . If in the unlikely event you do ever see a LTP, firstly read the LTP checklist on http://users.aber.ac.uk/atc/alpo/ltp.htm , and if this does not explain what you are seeing, please give me a call on my cell phone: +44 (0)798 505 5681 and I will alert other observers. Note when telephoning from outside the UK you must not use the (0). When phoning from within the UK please do not use the +44! Twitter LTP alerts can be accessed on https://twitter.com/lunarnaut .

Dr Anthony Cook, Department of Physics, Aberystwyth University, Penglais, Aberystwyth, Ceredigion, SY23 3BZ, WALES, UNITED KINGDOM. Email: atc @ aber.ac.uk

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Key to Images In This Issue

1. Alphonsus 16. Nicollet 2. Anaxagoras 17. Plato 3. Arago 18. Proclus 4. Aristarchus 19. Pythagoras 5. Bailly 20. Pytheas 6. Bessel 21. Ritter and Sabine 7. Copernicus 22. Schickard 8. Damoiseau 23. Serpentine Ridge 9. Dorsa Geikie 24. Sinus Aestuum 10. Grimaldi 25. Stöfler 11. Heraclitus 26. Stadius 12. Janssen 27. Stevinus 13. Lacus Mortis 28. Taruntius 14. Mare Crisium 29. Taurus-Littrow 15. Mare Orientale 30. Triesnecker 31. Tycho The Lunar Observer/November 2020/ 88