May 2020 in This Issue Online Readers, ALPO Conference Announcement 2 Lunar Calendar May 2020 3 Click on Images an Invitation to Join ALPO 3 for Hyperlinks

Home , Gruemberger (crater), List of lunar features, Lubiniezky (crater), Mons Hadley, Palus Epidemiarum

A publication of the Lunar Section of ALPO Edited by David Teske: [email protected] 2162 Enon Road, Louisville, Mississippi, USA Recent back issues: http://moon.scopesandscapes.com/tlo_back.html May 2020 In This Issue Online readers, ALPO Conference Announcement 2 Lunar Calendar May 2020 3 click on images An Invitation to Join ALPO 3 for hyperlinks. Observations Received 4 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 Cassini C and E, R. Hayes 9 Fauth, R. Hayes 10 Bright Triangles on the Great Dark Lake, A. Anunziato and F. Cardinalli 11 Pure Nectar, R. Hill 13 Banded Craters near Bullialdus, A. Anunziato and F. Cardinalli 14 Scheele Arc, A. Anunziato 15 Janssen Redox, R. Hill 17 Messier Shadows, H. Eskildsen 18 Heading South, R. Hill 20 The Hippalus Region, D. Teske 21 The Shore of Two Seas, R. Hill 23 Focus-On Lunar 1-10, J. Hubbell 24 Recent Topographic Studies 37 Lunar Geologic Change Detection Program T. Cook 94 Key to Images in this Issue 106

I hope that this issue finds you and your loved ones in good health in these uncertain times. In this issue of The Lunar Observer, Jerry Hubbell leads us on a tour of the Lunar 100, starting with the first 10 lunar targets. Response to this has been incredible! In the Recent Topographic Studies, several images of these first 10 lunar targets are highlighted. Thanks so much for each who submitted observations. Also, Robert H. Hayes, Jr. investigates the region of Cassini C and E, Alberto Anunziato and Francisco Cardinalli have tours of the Bullialdus region and the Scheele Arc, Rik Hill, Howard Eskildsen and David Teske guide the reader on lunar expeditions through the telescope. As always, Tony Cook leads the Lunar Geologic Change Program with his in-depth research.

Wishing each all the best in these times.

The Lunar Observer/May 2020/ 1

ALPO Conference November 6-7, 2020

Interested parties are hereby invited to submit papers and research posters on the astronomy-related topics of their choice for presentation at the next ALPO conference to be held jointly with the Georgia Regional As- tronomers Meeting (GRAM) when that group meets on November 6 and 7, 2020.

This will be the second time the ALPO has participated with the GRA group, the first time being the autumn of 2017.

Like last time, the was made after an online discussion and vote by the ALPO board of directors.

This year's conference will be at North Georgia College in Dalton, Georgia, approximately a one-and-a-half- hour drive north of downtown Atlanta. The ALPO portion of the conference will commence with the ALPO board meeting on Friday, November 6, to be followed by an informal gathering that evening with a lecture, social gathering with snacks and observing at the school’s on-campus observatory.

All papers will be presented the following day, Saturday, November 7, between 9 a.m. and 5 p.m.

Also as we did in 2017, there will be an ALPO dinner on Saturday evening where the Walter Haas Observ- ing Award and the Peggy Haas Service Award will be presented.

We have been allotted up to at least four (4) time slots for ALPO papers of no more than 15 minutes in length; the preferred method is 12 minutes for the paper presentation plus 3 minutes for follow-up questions. The preferred format is Microsoft PowerPoint.

We have also been invited to participate with wall-mounted research posters which are also commonly done at academic and professional conferences everywhere.

Participants are encouraged to submit research papers, presentations, and experience reports concerning var- ious aspects of Earth-based observational astronomy. Suggested topics for papers and presentations include the following: • New or ongoing observing programs and studies, specifically, how those programs were designed, im- plemented and continue to function. • Results of personal or group studies of solar system or extra-solar system bodies. • New or ongoing activities involving astronomical instrumentation, construction or improvement. Challenges faced by Earth-based observers such as changing interest levels, deteriorating observing conditions brought about by possible global warming, etc. A hard-copy version of your paper should be made available for future web site publication.

More details about paper presentations and to whom they should be sent will be published in the Summer issue of the ALPO Journal for release in early June.

The Lunar Observer/May 2020/ 2

Lunar Calendar May 2020

Date Time UT Event May 2020 4 Lunar south limb most exposed -6.6o 6 0300 Moon at perigee, 359,654 km 7 1045 Full Moon 11 Moon greatest southern declination -24.0o 12 1000 Jupiter 2o north of Moon 12 1800 Saturn 3o north of Moon 12 Lunar east limb most exposed +6.9o 14 1403 Last Quarter Moon 18 0800 Moon at apogee, 405,583 km Lunar north limb most exposed +6.7o 22 1739 New Moon, lunation 1205 24 0300 Venus 4o north of Moon 24 1100 Mercury 3o north of Moon 24 1500 Vesta 0.6o south of Moon, occultation much of North America, Europe 26 Moon greatest northern declination +24.0o 27 Lunar west limb most exposed -5.9o 30 0330 First quarter Moon

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.alpoastronomy.org/main/member.html which now also provides links so that you can enroll and pay your membership dues online.

The Lunar Observer/May 2020/ 3

Lunar Topographic Studies

Acting 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://moon.scopesandscapes.com/

Observations Received May 2020

Name Location and Organization* Article/image Jay Albert Lake Worth, Florida, USA Images of the Apennines, Theophi- lus and Copernicus

Alberto Anunziato Oro Verde, Argentina, SLA-LIADA Article and drawing Scheel Arc, Article and image Banded Craters, Ghost Craters and Other Beauties Around Bullialdus, Article and 4 images Bright Triangles on a Dark Lake, images of Agrippa, Coperni- cus and Mare Crisium Sergio Babino Montevideo, Uruguay, SAO-LIADA Images of Aristarchus, Montes Ap- enninus (3), Copernicus, Tycho, Mare Crisium and Theophilus Juan Manuel Biagi Oro Verde, Argentina, SLA-LIADA Images of Posidonius and Earthshine

Aylen Borgatello AEA - Oro Verde, Entre Rios, Ar- Image of Plato gentina Francisco Alsina Cardinalli Oro Verde, Argentina, SLA-LIADA Article and image Banded Craters, Ghost Craters and Other Beauties Around Bullialdus, Article and 4 images Bright Triangles on a Dark Lake, images of Montes Apenninus, Linné, Eratosthenes, Archimedes, Tycho (2), Copernicus (2), Colom- bo, Censorinus, Theophilus (2), Cla- vius and Mare Crisium (2) Jairo Chavez Popayán, Colombia, SLA-LIADA Images of 61% Waxing Gibbous Moon (2), 98% Waxing Gibbous Moon (2), Full Moon (5), Montes Apenninus (2) and Mare Crisium Abel David Emiliano Gonzalez Cian AEA - Oro Verde, Entre Rios, Ar- Images of Hyginus N, Tycho, Plato, gentina Ross D, Gassendi (2), Copernicus, Littrow, Aristarchus (2) Leonardo Alberto Colombo Cosquín, Argentina, SLA-LIADA Image of Tycho

Michel Deconinck Michel Deconinck - Artignosc-sur- Drawings of Clavius, Mare Crisium, Verdon - Provence - France Tycho, Earthshine, Theophilus, Full Moon and Copernicus

The Lunar Observer/May 2020/ 4

Observations Received continued Name Location and Organization* Article/image Marc Delcroix Images of the 4.4-day old Moon, 10.5- day old Moon, 11.5-day old Moon and 15.6-day old Moon Walter Ricardo Elias Oro Verde, Entre Rios, Argentina, Images of Piccolomini, Waxing Cres- AEA cent Moon, Schickard, Promontorium Agarum, Proclus (2), Aristarchus (5), Tycho, Plato (4), Gassendi (3), Eim- mart, Darney, Copernicus, Censori- nus,(2), Bullialdus (2) and Alphonsus (2) Hugo Espina Montevideo, Uruguay, SAO-LIADA Image of the Full Moon Howard Eskildsen Ocala, Florida, USA Articles and image Messier Shadows, images of Montes Apenninus (2), Pic- colomini Dome and Archytas-G- Dome_ Diego Etchevers Montevideo, Uruguay, SAO-LIADA Image of the Waning Gibbous Moon Diego Ferrandas Villa María, Argentina, SLA-LIADA Images of Mare Crisium and Theophi- lus Desireè Godoy Oro Verde, Argentina, SLA-LIADA Images of Tycho, Linné, Mons Hadley and Clavius Fernando Gomez Montevideo, Uruguay, SAO-LIADA Image of Earthshine Victoria Gomez AEA - Oro Verde, Entre Rios, Argen- Image of Mons Vinogradov tina Gramer, Facundo AEA - Oro Verde, Entre Rios, Argen- Images of Littrow, Copernicus and tina Atlas Marcelo Mojica Gundlach (Cochabamba, Bolivia, SLA-LIADA Images of Rima Herigonius, Norman, Gassendi, Vitello, Bullialdus, Longo- montanus, Copernicus (2), Capuanus, Tycho (2), Eratosthenes and Clavius (2) Robert H. Hayes, Jr. Worth, Illinois, USA Article and drawing Cassini C & E Rik Hill Tucson, Arizona, USA Images and articles Pure Nectar, Heading South, Janssen and The Shore of Two Seas Jerry Hubbell Wilderness, Virginia, USA Focus-On Article Lunar 100 Numbers 1-10, image of Tycho Carlos Lobato San José de Carrasco, Uruguay Drawing of Gassendi Luis Mansilla Rosario, Argentina, LIADA-LIADA Image of Tycho Raúl Roberto Podestá Formosa, Argentina, SLA-LIADA Images of Montes Apenninus and De- slandres Gabriel Re AEA - Oro Verde, Entre Rios, Argen- Images of Tycho and Proclus tina Pedro Romano San Juan, Argentina, SLA-LIADA Image of Mare Serenitatis Gabrielle Scarponi Montevideo, Uruguay Images of the 76% Waning Gibbous Moon (2), 56% Waxing Gibbous Moon and 33% Waxing Crescent Moon Fernando Surà San Nicolás de los Arroyos, Argentina, Image of Clavius SLA-LIADA Michael Sweetman Tucson, Arizona, USA Images of the Full Moon, Timocharis, Altai Scarp and Theophilus David Teske Louisville, Mississippi, USA Article and image Hippalus Region, image of Mare Crisium Román García Verdier Paraná, Argentina ,SLA-LIADA Image of Tycho

The Lunar*SLA Observer/May is Sociedad 2020/Lunar 5 Argentina, LIADA is Liga Iberoamericana de Astronomía (LIADA).

SUBMISSION THROUGH THE ALPO IMAGE ARCHIVE ALPO’s archives go back many years and preserve the many observations and reports made by amateur 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 Sinus Iridum, 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 format, reduces the effort to post the images significantly. Observers who submit digital versions of drawings 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/May 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 following 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 telescope 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 images. 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 feature or class of features. The subject for the July 2020 edition will be the Lunar 100 numbers 11- 20. 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 11-20 article is June. 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 11-20) July 2020 June 2020 Lunar 100 (numbers 21-30) August 2020 September 2020

The Lunar Observer/May 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 11-20 will be featured in the July 2020 The Lunar Observer. Submissions of articles, drawings, images, etc. due by June 20, 2020 to David Teske and Jerry Hubbell.

L Feature Name Significance Rükl Chart 11 Aristarchus Very bright crater with dark bands on its wall 18 12 Proclus Oblique impact rays 26 13 Gassendi Floor-fractured crater 52 14 Sinus Iridum Very large crater with missing rim 10 15 Straight Wall Best example of a lunar fault 54 16 Petavius Crater with a domed and fractured floor 59 17 Schröter’s Valley Giant sinuous rille 18 18 Mare Serenitatis dark edge Distinct mare areas with different compositions 24 19 Alpine Valley Lunar graben 54 20 Posidonius Floor-fractured crater 14

Explore the Lunar 100 on the link 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

The Lunar Observer/May 2020/ 8

Cassini C and E Robert H. Hays, Jr.

Cassini C & E, Robert H. Hays, Jr., Worth, Illinois, USA. 05 December 2019 0236-0320 UT. 15 cm reflector, 170 x. Seeing 6 -8/10, transparency 6.

I drew this area on the evening of Dec. 4/5, 2019. These are the two main craters northeast of Cassini itself. Cassini C is the largest crater on this sketch. It showed substantial exterior as well as interior shadow at this time. A conspicuous ridge protrudes from the north rim. A small peak and other ridges and strips of shadow are to its south and east. Cassini E is a smaller version of C with similar shad- owing. There is a tiny peak just south of Cassini E, and several peaks are to its north and northeast. Two more peaks are west of Cassini C and E. Cassini F is the smaller crater south of Cassini C. Two large mountains dominate the scene west of these craters. The northern on is bigger and is surrounded by several smaller peaks. A vague strip of gray shadow was within it at this time. The southerly mountain showed a notch in its shadowed side, perhaps from some protrusion catching sunlight. A tiny peak is just to its east. These mountains are not shown as such on the Lunar Quadrant map, but a ghost ring is depict- ed there. Cassini N is the small pit in the area. All lettered craters are similarly crisp, differing only in size. The area between Cassini C, Cassini F and the southerly mountain appears to be very smooth and relatively dark.

The Lunar Observer/May 2020/ 9

Fauth Robert H. Hays, Jr.

Fauth, Robert H. Hays, Jr., Worth, Illinois, USA. 07-08 November 2019 0110-0138 UT. 15 cm reflector, 170 x. Seeing 6- 8/10, transparency 6.

I drew this double crater and vicinity on the evening of 7/8 November 2019. This area is just south of Co- pernicus. Fauth actually refers to this feature’s larger north portion. The southern part is Fauth A. The two parts appear to be equally crisp and deep with no rim between them. A group of elevations lie north of Fauth. Three slightly curved ridges are at the east end of this group. A bright peak and a large low mound are nearby. A long straight ridge and two low hills are farther west. A tiny peak is just south of Fauth A. Several small craters are in the vicinity. Fauth B is east of Fauth A, and Fauth C is to its southeast. Fauth C also has a bright interior. Reinhold G is almost due south of Fauth, and has a small bright patch at its south end. A tiny peak could be glimpsed at times north of Reinhold G. Fauth E is the very small pit southwest of Fauth A. Fauth G, GA and F are a compact trio west of Fauth; F is the largest and westernmost of this group. Fauth GA appears to be shallower than its neighbors. The area around Fauth and the craterlets is at the edge of Oceanus Procellarum, and is somewhat darker than the terrain to the north.

Please note, in the April 2020 The Lunar Observer, this article and drawing by Robert H Hays, Jr. first appeared. Robert noted an omission in the April 2020 drawing. Above is the corrected drawing. Thanks Robert!

The Lunar Observer/May 2020/ 10

Bright Triangles on the Great Dark Lake Francisco Alsina Cardinalli and Alberto Anunziato

Probably Plato is the most peculiar crater on the Moon. We are amazed by its almost completely flat and dark floor. Sunk two kilometers beneath the level of the Alps where it is located, interrupted only by a few small craters (very difficult to discern), a dark and huge mass of basaltic lava fills an oval of more than 100 kilometers in diameter. A romantic landscape that is dramatically accentuated when the shadows of the eastern rim cast sharp shadows that look like claws that extend to the western rim, revealing irregularities in the western rim that cannot be observed directly. Another unknown is how so much lava came into Pla- to's interior if no openings are observed at the rim, lava that flooded a hypothetical central peak that would have to rise 1.5 kilometers above the surface according to the models that explain the impact craters. Among these fascinating features of which we choose the two bright sides triangles that we can observe on the western rim. They are two huge blocks disconnected from the steep rim and that have had to slide down in gigantic landslides of which we don't know their causes. In image 1 (18.2o colongitude) the terminator moves away from Plato and only parts of its west rim are illuminated: the most prominent triangle, a thin line to the south and to the north a very bright spot and some high areas. Image 2 (18.8o colongitude) was obtained with the same instruments just over an hour later and the edges of the famous dish triangle are clearly determined and inside it we can see a shaded area to the west and a lighter one to the east. The second triangle to the north appears sharper than in image 1. In image 3 (24.2º colongitude) the panorama is clearer and if we zoom in, some details of the surface inside both triangles are captured. In image 4 (colongitude78.0º) we observe Plato in full moon and it is interesting to observe how even with frontal sunlight the main triangular massif is still visible. An additional detail, which arises from the analysis of Plato's images is the west wall of Bliss crater, west of Plato (22 km diameter) present in all the images what appear to be radial bands.

Figure 1, Plato, Francisco Alsina Cardinalli, Oro Verde, Argentina, SLA-LIADA. 20 December 2015 0053 UT. 250 mm Meade LX 200 Schmidt Cassegrain telescope, Canon EOS Digital Rebel XS camera.

The Lunar Observer/May 2020/ 11

Figure 2, Plato, Francisco Alsina Cardinalli, Oro Verde, Argentina, SLA-LIADA. 20 December 2015 0206 UT. 250 mm Meade LX 200 Schmidt Cassegrain telescope, Canon EOS Digital Rebel XS camera.

Figure 3, Plato, Francisco Alsina Cardinalli, Oro Verde, Argentina, SLA- LIADA. 20 August 2018 2334 UT. 200 mm refractor telescope, QHY5-II camera.

Figure 4, Plato, Francisco Alsina Cardinalli, Oro Verde, Argentina, SLA-LIADA. 19 June 2016 0522 UT. 250 mm Meade LX 200 Schmidt Cassegrain telescope, 742 nm IR pass filter, QHY5-II camera.

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Pure Nectar Rik Hill

One of the more spectacular regions on the moon is that of Mare Nectaris, pure nectar to the lunar observer! Two things catch the eye right off: Rupes Altai, which we old timers used to call the Altai Scarp, and the Theophilus trio of craters. The weather was very hazy with rapidly moving Cirrus and mediocre seeing but I gave it a go anyway.

Mare Nectaris, Richard Hill, Tucson, Arizona, USA, Loudon Observatory. 30 March 2020 0207 UT, colongitude 339.3o. Dynamax 6 telescope plus Good- win barlow, 850 nm filter, Skyris 445M camera. Seeing 5-6/10 with thin clouds.

Rupes Altai is the bright jagged line that appears to emanate from a fairly good-sized crater at the lower middle of this image and meanders off to the northwest (upper left). The crater is Piccolomini (90 km diameter) with a flat floor and a nice central peak casting its shadow almost to the western wall. The Rupes is concen- tric with the lava filled basin of Mare Nectaris that dominates the upper right of this image. It is literally a partial crater wall to this large basin rising 3-4 km as it snakes northward. Notice the sinuosity of the uppermost end! It ends in this image just west of the large crater Catharina (104 km) which is overlain by a smaller 'satellite' crater Catharina P (46 km). A little farther north and we see Cyrillus (100 km) which is overlain by the majestic Theophilus (104 km) with its beautifully terraced walls and pingo-like central peak. It's a little counter- intuitive but the north wall of this monster crater is actually about 1km lower than the south crater wall. Note the wonderful field of eject from this crater to the north filled with thousands of secondary craters up to and past the small pear-shaped crater at the top of this image. This crater, filled with shadow, is Torricelli (12x24 km) sitting in a larger 87 km diameter ghost crater ring Torricelli R. To the east of Theophilus is the crater Mädler (29 km) roughly the same age as its big brother. Then on the other side of Theophilus is a bright massif Mons Penck rising some 4 km above the floor around it. What a sight you would have to the southeast if you could Stand on top of this massive mountain.

We have seen the spectacular features that cup Mare Nectaris on the south and southwest side but there are several very interesting 'U' shaped features in the middle. In just about the middle of this image is a large crater Fracastorius (128 km), a crater whose lower north wall was flooded by lava during the Necta- ris impact filling the floor of this crater. There is an interesting rima or rille in the center of this crater run- ning east-west, that I did not catch in this image due to weather conditions. Just north and west of Fra- castorius is an almost identical crater but under half its diameter. This is Beaumont (54 km). It lies on the south end of an unnamed dorsum that connects it with Theophilus. There are a lot of other interesting features in this region for you to discover showing that even on so-so nights you can enjoy the Moon!

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Banded Craters, Ghost Craters and Other Beauties Around Bullialdus Alberto Anunziato and Francisco Alsina Cardinalli

The star of the image is undoubtedly Bullialdus. We can think that in some billions of years Copernicus will look very similar to Bullialdus, which belongs to the Eratosthenian Period. Both share some charac- teristics such as very steep and tormented slopes, very high walls in terraces, flat floor and multiple central peaks, but Bullialdus has almost completely lost its bright rays. Bullialdus was the subject of the Fo- cus-On of the July 2012 issue of “The Lunar Observer” and the curious reader can refer there to learn more about this spectacular crater. The detail that I like the most in the image is the clearly defined central peaks. In Wayne Bailey's article from that issue of TLO we learned that: “Bullialdus A is blanketed by this ejecta, showing that it existed at the time of the impact that formed Bullialdus. Bullialdus B, however, is superimposed on this material, indicating it is the youngest of the three craters”. The rays that are observed dominating the scene are those of the not so close Tycho. Even omitting the nearby Rupes Recta, Mare Nubium presents a series of features of great interest. One of them is heart-shaped, certainly what little remains of the Pre-Imbrian Wolf is highly suggestive (below, right). On the other side of Bullialdus, we find the steep slopes and high walls of König, and to its right part of some crater submerged by the lava that formed the Mare Nubium. A little above König we find an isolated circular formation, almost a ghost crater: Kies. And on the other side of Bullialdus, towards the north (bottom of

Bullialdus, Luis Francisco Alsina Cardinalli, Oro Verde, Argentina, SLA-LIADA. 12 December 2016 0030 UT. 200 mm Meade Starfinder reflector telescope, 742 nm IR pass filter, QHY5-II camera.

The Lunar Observer/May 2020/ 14

the image), we find another circular formation, the ghostly Lubiniezky (named after the Polish author of one of the most fascinating astronomical books, the Theatrum Cometicum). And while it's not a ghost crater, Hippalus is a crater so old and deteriorated that it almost looks like it. It is located under Cam- panus and Mercator, very similar in shape and size they look like a pair of spectacles. Hippalus B (5 km diameter) appears very sharp, slightly displaced from the center of Hippalus. The spectacular Rima Hip- palus (an arcuate rille) passes alongside Hippalus B and crosses Hippalus to its full extent. Now let's talk about the spectacular banded craters seen in the image. The most spectacular is Agatharchides A (between Bullialdus and Hippalus). It is only 16 kilometers in diameter but its bands are clearly distin- guished. Agatharchides gives name to the Group 5 in the ALPO Banded Craters Program typology: “Group 5 - (Agatharchides A type) One half of the floor is dull and the bands radiate from near the wall inside this dull section and are visible on the dull and bright parts of the floor”. Then follow Mercator A, to the right of Mercator. Its clear bands are so bright that they stand out despite their small diameter (9 kilometers). The Mercator A ejection mantle is very bright too, it must be a crater from the Copernican period. Kies A is also a crater with fairly marked bands and small diameter, south of Kies (above in our image).

Scheele Arc Alberto Anunziato

At 50.9o colongitude, the proximity of the terminator favored the observation of smooth elevations nearby Letronne, like the remains of a partially destroyed crater and almost completely covered by the lava that formed the Oceanus Procellarum. As I observed the Virtual Moon Atlas helped me to identify the flooded crater, but no close feature appeared in the program's nomenclature. While drawing I indicated Wichmann, Scheele and Herigonius as references. Incredibly, it took me less time to draw this ghost crater than to find out its name. It was an arduous search to find the location of what I had observed in lunar atlases and images on the internet, in an area where the Oceanus Procellarum reaches the Riphaeus Mountains and where almost completely flooded ancient craters abound. It was in the maps of the Lu- nar Chart (LAC) Series of the Aeronautical Chart Information Center of the United States Air Force (https://www.lpi.usra.edu/resources/mapcatalog/LAC/ ), in the LAC 75 Letronne chart, where I could locate with more precision the ghost crater that was in the best observing conditions that night. Then it was easier to find it in the Atlas of the Moon by Antonin Rükl and Gary Seronik, Chart 41 Euclides. Find the name of the feature was also a hard work. It was on the old reliable “The Moon-Wiki” (https:// the-moon.us/wiki/Scheele ) that I was able to find the unofficial name of this accident: “Scheele Arc”: “curious arc (the remains of a large crater) east of Scheele is unofficially called Scheele Arc by D. Caes. Three sections of the rim of this large crater were once called Wichmann Delta, Wichmann Rho, and Euclides Epsilon. In our image we see that only part of the eastern wall (Euclid Epsilon), almost all of the western wall (Wichmann Rho) and part of the north wall (Wichmann Delta) remain from the ancient crater. The south wall, however, appeared as a slight rima-like shadow, joining with the transverse ex- tensions of the Rima Herigonius. As the light conditions were very good, with the terminator nearby, it was possible to distinguish which are the highest areas of the remains of the walls of a forgotten crater. All shadows are outlined to the west, at the northern end of the west wall is the highest, brightest area that casts the most widespread shadow. The south end of the north wall is also very bright, facing the north end of the west wall, but no pronounced shadows are seen. To the north the shadows mark a nar- row corridor with a small parallel mountain range. From Wichmann Delta there is a shadow, not identi- fied in the aforementioned charts, which culminates in a very bright point. The east wall has a brighter area near its northern extreme and ends in the south with the largest craterlet seen in the image. To the southeast is an isolated peak that belongs to the Scheele Hills, another unofficial name in a little-known area.

The Lunar Observer/May 2020/ 15

Scheele Arc, Alberto Anunziato, Paraná , Argentina, SLA-LIADA. 04 April 2020 0000-0015 UT. 105 mm Meade ETX Maksutov-Cassegrain telescope.

The Lunar Observer/May 2020/ 16

Janssen redux Rik Hill

During my downtime I bought a Dynamax 6 for a very good price. Almost unused by the original owner, it was just a process of kicking out the cobwebs, tightening screws and aligning optics. The latter has been the hardest and may eventually require disassembly and cleaning of the secondary alignment system before the final tweak can be had. Still, it has done a good job of it.

Near the center we see Janssen, a low large crater of 196 km diameter with fascinating rimae curved across its floor. To the north are two nicely defined craters. Just inside the northern border of Janssen is Fabricius (80 km) with a central peak and a central mountain range! Further north just outside Janssen is a crater 10 km larger, Metius. Above Metius is a gash in the Moon. This is Vallis Rheita created from a series of merged craters with large crater Rheita (70 km) on the left end and Young D (46 km) on the right end.

To the right of Janssen can be seen two overlapping craters. First is Steinheil (70 km) which is on top of Watt (68 km). Two more impressive craters are at the bottom of this image. The left one is Valcq (92 km) with a central peak casting a shadow across the floor and to the right is Rosenberger (99 km). All is all, not bad for a 40-year old 6” telescope!

Janssen, Richard Hill, Tucson, Arizona, USA, Loudon Obser- vatory. 29 March 2020 0237 UT, colongitude 329.2o. Dy- namax 6 telescope plus Good- win barlow, 610 nm filter, Skyris 445M camera. Seeing 6/10.

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Messier Shadows Howard Eskildsen

The telescopic image (figure 1), taken at low sun-angle, shows ear-like shadows extending east of Messier, which by coincidence are in the opposite direction of the downrange rays from the oblique impact. This implies that the crater rim is higher at mid crater, perpendicular to the path of the oblique impact. The Messier A shadow appears more typical without the “ears” shown by Messier. However, its rim has an un- even, wrinkled appearance at mid crater perpendicular to the impactor path of travel.

The LROC draw/search tool was used to generate elevation profiles. Figure 2 verifies that the up-range portion of Messier’s crater wall, as well as the downrange portion are much lower than the middle segments of crater wall. The up-range wall is slightly higher than the downrange wall. Figure 3 shows the up- range wall of Messier A to be similar in elevation than the middle wall segments, though it is slightly higher than its downrange wall. Also, the LROC image shows clumped wings of ejecta in the same area as the “wrinkles” seen on Messier A in Figure 1.

I wonder if the pattern of low rim elevation on the up-range and downrange portions compared to mid crater rim elevations is a general characteristic of an oblique crater, or if it is unique to this crater pair. I will be looking.

Messier and Messier A, Howard Eskildsen, Ocala, Flori- da, USA. 11 April 2020 1009 UT, colongitude 129.6o. Celes- tron 9.25 Schmidt- Cassegrain telescope, f/10, fl 2395 mm, W- 25 red filter, Skyris 236M camera. See- ing 5/10, transparency 2/6.

The Lunar Observer/May 2020/ 18

Figure 2, Messier LROC

Figure 3, Messier A LROC

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Heading South Rik Hill

Another night with the Dynamax 6 as I continue to “shelter in place” during the Coronavirus outbreak. Here we have one of the more identifiable craters on the Moon, Clavius (225 km in diameter) just above center her, containing its impressive arc of smaller craters starting with Rutherfurd (56 km) on the southeast rim (lower right) of Clavius and then going through a series of the Clavius satellites decreasing in size while curving to the north and east. On the north rim is a crater similar to Rutherfurd. This is Porter (54 km). Just outside the wall to the southwest are two similar sized craters. The southernmost one with the relatively smooth floor is Blancanus (109 km) and just north and west of it is Scheiner (114 km). South of Blancanus is a very flat floored crater, Klaproth (122 km) and further south is Casatus (114 km). To the left are two more similarly sized crater mostly filled with shadow. The lower one in Kircher (75 km) and the one above, with a little central peak is Bettinus (73 km).

On the right edge of the image about halfway up is a crisp, neat round crater that is nicely defined. This is Cysatus (51 km) and it is adjacent to Gruemberger (97 km) on the left or west side. Straight down the right side of the image leads you pretty close to the south pole of the Moon but not at the libration. The Moon’s north pole is tilted towards us on this night!

Clavius, Richard Hill, Tucson, Ari- zona, USA, Loudon Observa- tory. 05 April 2020 0215 UT, colongitude 53.3o. Dynamax 6 telescope plus Good- win barlow, 610 nm filter, Skyris 445M camera. Seeing 7/10.

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The Hippalus Region David Teske

I always enjoy seeing the Hippalus region and Mare Humorum when it is near the terminator. There is such an interesting wealth of details visible here. In the image on the next page, we view Hippalus near lunar sunset. Hippalus itself is a destroyed crater that is 58 km across. The western walls of Hippalus are long gone, so it looks like a bay opening into the Mare Humorum. Named after Hippalus, a Greek sailor who around 120 A.D. sailed the open sea from Persia to India, the crater is most remarkable for the rilles that run through it. The Rimae Hipparchus is an extraordinary rille system consisting of three main rilles. Each of these rilles are 2-3 km wide and stretch in an arc over a length of just under 200 km. The curva- ture of the rilles follows the outer margin of Mare Humorum. The westernmost of these three rilles runs right through the crater Hippalus. The Rimae Hippalus are parallel grabens, the longest of which extend over a quarter of the circumference of Mare Humorum. The rille extends north past Hippalus for another 60 km, ending near an ancient structure designated Agatharchides P and in the other direction rilles can be traced as far as the hilly region east of the crater Vitello. Careful examination allows us to understand the sequence of what happened in this region. Long ago, in the Nectarian period 3.8 to 3.9 billion years ago, an asteroid struck the Moon and formed the impact basin that became the ‘Sea of Humours’, a basin about 380 miles across, about the size of Iceland. Some time later, near the outer edge of this basin, a much smaller asteroid collided with the Moon, forming the crater Hippalus. After this, lava flooded the Humorum basin, causing craters along its periphery to subside on the seaward side. Craters such as Hip- palus thus lost their seaward walls. As the lavas cooled, the lava layers collapsed under their weight and deformed the crust beneath to form wrinkle ridges, fracture zones such as the Rimae Hippalus and escarp- ments around the edge of the basin. Just east (right) of Hippalus the rille was destroyed by a much younger crater, Agatharchides A, a 20 km wide crater.

Just west (left) of Hippalus out in Mare Humorum is an ‘island’, Promontorium Kelvin, a free standing large mountainous ridge that stands 1,000 m above Mare Humorum and is likely part of Humorum’s multi-ring structure. Just south of Promontorium Kelvin, the southeast ‘shore’ of Mare Humorum is a 150 km long scarp named Rupes Kelvin which is likely a portion of the inner wall of the Humorum Basin. Rupes Kelvin appears as an uplifted line of hills between the craters Hippalus and Vitello. The scarp also marks the western boundary of an unusual square patch of hills between Campanus and Vitello. This square patch may be associated with Humorum’s multi-ring structure. Parts of the Hippalus rilles run into this square of hills.

In the late lunar day when this image was taken, a number of other rilles are seen in this area. One can be seen on the smooth floor of Agatharchides P at about 1 o’clock from Hippalus. Another rille runs directly between Campanus and Mercator that parallels the Hippalus rilles. This rille ends in Palus Epidemiarum (the marsh of epidemics). South of that, a complicated system of short rilles is located around the crater Ramsden in this mare area.

North of Hippalus is the 49 km diameter flooded crater Agatharchides, named after the Greek geographer and Historian who lived in the second century BC. North of this out in Oceanus Procellarum is the Hel- met, a 60 by 45 km light patch of non-mare volcanics like the Gruithuisen Domes far to the north.

The Lunar Observer/May 2020/ 21

References

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

Kitt, Michael T. 1992. The Moon: An Observing Guide for Backyard Telescopes. Kalmbach Books, Waukesha.

Legault, Thierry and Brunier, Serge. 2006. New Atlas of the Moon, Firefly Books.

Rükl, Antonin: Atlas of the Moon, Kalmbach Books, 1990.

Wilkinson, John. 2011. The Moon in Close-Up. Spinger, Heidelberg.

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

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

Hippalus, David Tes- ke, Louisville, Missis- sippi, USA,23 Septem- ber 2019 at 1021 UT, colongitude 200.8o. 180 mm Takahashi Mewlon, ZWOASI120mms, 500 frames, Firecapture, Registax, Photoshop. Seeing 7/10.

The Lunar Observer/May 2020/ 22

The Shore of Two Seas Rik Hill

Of the more fascinating formations of the Moon are these two mountain ranges that divide Mare Serenitatis to the right (east) and Mare Imbrium to the left (west). The northern mountains are Montes Caucasus, a triangular patch of mountains with the crater Eudoxus (70 km) to the north, Calippus (34 km) in the middle and Theaetetus (26 km) on the west side. Further on the west past Theaetetus is the low walled Cassini (60 km) with Cassini A (17 km) contained inside. This is a wonderful mountain range with many interesting features.

South and west of this we see a notable trio of craters. In order of size they are Archimedes (85 km), Aris- tillus (56 km) and Autolycus (41 km). Archimedes is known for reports of transient phenomena involving coloration on the floor reported over many decades. To the east or right of right of Archimedes is a rather smooth area Palus Putredinus that separates the crater from the magnificent mountain chain, Montes Apen- ninus. Notice near where the Palus and mountains intersect, a little white ‘x’. This is where Apollo 15 landed at “Hadley Rille” known more properly as Rima Hadley. You can see the rille if you go to 100% resolution on this image. Over near the right edge of the image you will see a white spot out in Mare Se- renitatis. This is the crater Linné (3 km), the crater reported in the 19th century, to have gone through some changes. Spacecraft images over the last 70 years have pretty much ruled this out. If you go to this area of the Moon, spend some time along the Apennines seen at the bottom of this image. It’s very rewarding!

Eudoxus to Archimedes, Richard Hill, Tucson, Arizo- na, USA, Loudon Observato- ry. 03 April 2020 0304 UT, colongitude 40.9o. Dynamax 6 telescope plus Goodwin 1.5 x barlow, 610 nm filter, Skyr- is 445M camera. Seeing 7/10.

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Focus On: The Lunar 100 Features 1 through 10

Jerry Hubbell Assistant Coordinator, Lunar Topographical Studies

This is the first article of ten in a new series on Chuck Wood’s Lunar 100 list. Chuck Wood, the founder of the Lunar Photo of the Day (LPOD) (Ref.), first discussed this list of lunar features 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 Messier 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, Craters, Rilles, Mountains, and Volcanic Domes. The list starts out with the naked eye 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 allow 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 narrative descriptions, drawings and images. 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 different phases of the Moon.

One of the best ways to help you learn the features of the Moon is through sketching the lunar surface. 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 start out easy with the first 10 features on Chuck’s list. If you are a beginning lunar observer, this first article will be a great way to start learning about the features of the Moon using your naked eye and binoculars. Here is a list of these first 10 features:

Designation Feature Name Description/Significance L1 The Moon Satellite of the Earth – Full Moon L2 Earthshine Twice Reflected Sunlight L3 Mare/Highland Dichotomy Two Distinct Lunar Topography Types L4 Apennines Imbrium Basin Rim L5 Copernicus Large Complex Impact Crater L6 Tycho Large Rayed Crater L7 Altai Scarp Nectaris Basin Rim L8 Theophilus, Cyrillus and Catherina Three Craters Showing Different Stages of Degradation L9 Clavius Largest Impact Crater Lacking Basin Features L10 Mare Crisium Mare Contained within A Large Basin

The Lunar Observer/May 2020/ 24

The Lunar 100: Feature 1 – The Moon

The Lunar 100 Feature 1 The Moon Figure 1. Full Moon, Michel Deconinck, Artignosc-sur-Verdon, Provence, France, 29 August 2015 2000 UT, Co- longitude 92.2°, Bresser 102/1000, double polarizing filter, Magnification 25x, pastels Conté grey, black and white + blending stump on Canson paper 240gr black. Seeing 9/10, Transparency 6/6. North/Up, East/Right.

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The Lunar 100: Feature 2 –Earthshine

The Lunar 100 Feature 2 Earthshine Figure 2. Earthshine, Michel Deconinck, Artignosc-sur-Verdon, Provence, France, 17 May 2018 1930 UT, Colongi- tude 302.5°, Bresser 152/1200, Magnification 30x, pastels Conté + blending stump on Canson paper 240gr black. Seeing 6/10, Transparency 5/6. North/Up, East/Right.

The Lunar Observer/May 2020/ 26

The Lunar 100: Feature 3 –Mare/Highland Dichotomy

The Lunar 100 Feature 3 Mare/Highland Dichotomy Figure 3. Mare/Highland Dichotomy, Gabriel Scarponi, Montevideo, Uruguay, 12 April 2020 0827 UT, Colongi- tude 141.2°, 70-mm Refractor, Samsung A5 Cellphone. West/Up, North/Right.

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–Appenines

The Lunar 100 Feature 4 Apenninies Figure 4. Apennines, Howard Eskildsen, Ocala, Florida, USA, 02 April 2020 0100 UT, Colongitude 15.5°, C9.25 SCT f/10 FL 2395 mm, Celestron Skyris 236M. Seeing 6/10, Transparency 5/6. North/Up, East/Right.

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Lunar 100: Feature 5 –Copernicus

The Lunar 100 Feature 5 Copernicus Figure 5. Copernicus, Sergio Babino, Montevideo, Uruguay, SLA-LIADA, 26 February 2018 0037 UT, Colongitude 38.3°, 203mm SCT, ZWO 174MM, North/Up, East/Right.

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Feature 6 –Tycho

The Lunar 100 Feature 6 Tycho Figure 6. Tycho, Jerry Hubbell, Mark Slade Remote Observatory (MSRO) Wilderness, Virginia, USA. 02 February 2019 0900 UT, Colongitude 122.2°. 165 mm APO refractor + 0.7x FRFF + Red Filter, QHY 163C camera, 100/150 frames, MaxIm DL, Registax 6, Photoshop. Seeing 6/10, Transparency 5/6. North/Up, East/Right.

The Lunar Observer/May 2020/ 30

Lunar

The Lunar 100 Feature 7 Altai Scarp and Nectaris Basin Figure 7, Altai Scarp at sunset, Michael Sweetman, Tucson, Arizona, USA. Sky Crest Observatory. 06 February 2018 1135 UT. 3 inch Vixen/Celestron achromatic refractor telescope f/11 at f/22, Skyris 132M camera, Baader fringe killer. Seeing 4/10, transparency 3/6. Basin

The Lunar Observer/May 2020/ 31

The Lunar 100: Feature 8 – Theophilus, Cyrillus, Catharina

The Lunar 100 Feature 8 Theophilus, Cyrillus and Catharina Figure 8. Theophilus, Cyrillus and Catharina, Jay Albert, Lake Worth, Florida, USA, 05 October 2019 at 0103 UT. Colongitude 345.3°, 200 mm f/10 Celestron 8” NexStar Evolution SCT , 7mm Orthoscopic eyepiece projection, iPho- ne 6s Camera, Seeing 6/10, North/Up, East/Right.

Jay Albert sent the following message with his image:

“I sent you photos of the Apennines and Copernicus a few days ago. Going through my image files I came across one of Theophilus, Cyrillus and Catharina that I took last fall. I cropped and reprocessed in Photoshop Elements and resized it to try to fit your specs. The date and time are in the filename. I used a Celestron NexStar Evolution 8”SCT and shot through a 7mm orthoscopic eyepiece with my iPhone 6s attached with Celestron’s NexYZ cellphone adapter. The sky was hazy that night with 2nd magnitude transparency and 6/10 seeing. Image orientation is roughly N-S. Hope you can use this. Please let me know if you have any questions or comments. Thanks” – Jay Albert

The Lunar Observer/May 2020/ 32

The Lunar 100: Feature 9 – Clavius

The Lunar 100 Feature 9 Clavius

Figure 9. Clavius, Desireé Godoy, Oro Verde, Argentina, SLA-LIADA, 10 September 2016 at 2315 UT. Colongitude 22.9°, 279 mm f/11 Celestron 11” Edge HD SCT, QHY5-II Camera, North/Up, East/Right.

The Lunar Observer/May 2020/ 33

TLunar 100: Feature 10 – Mare Crisium

The Lunar 100 Feature 10 Mare Crisium Figure 10. Mare Crisium, David Teske, Louisville, Mississippi, USA, 06 March 2010 at 0232 UT. Colongitude 44.8°, 3.5-inch Questar with IR blocking filter , ZWO ASI120 MM/S camera, Firecapture, Registax, Photoshop, Seeing 8/10, North/Up, East/Right.

The Lunar Observer/May 2020/ 34

We had a very large response to our request for images and drawings for the first 10 features of the Lunar 100. We even had a few of the images taken with cellphone cameras – isn’t technology great! I am grateful for all the submissions. We had a total of 82 images and drawings submitted from a over 20 astronomers. Well over half, 51 of the 82 images came from Alberto Anunziato’s groups, SAO-SLA, and LIADA. He prefaced the 51 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 there- fore 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 images 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 lunar observation and if the call is successful, we can dream of some final joint publication.”

We look forward to the images the SLA, SAO, and LIADA members share with us and hope to see everyone participate in these Focus On articles. 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., Russell 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)

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

International Astronomical Union Gazetteer of Planetary Nomenclature, 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)

The Lunar Observer/May 2020/ 35

Aeronautical Chart Information Center (ACIC), United States Air Force, LAC Series Chart Reference, hosted 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 & Paul Spudis. 2004. The Clementine Atlas of the Moon. Cambridge University Press, New York.

Byrne, Charles. 2005. Lunar Orbiter Photographic Atlas of the Near Side of the Moon. 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 Nomen- clature. 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 Collins. 2012. 21st Century Atlas of the Moon. Lunar Publishing, UIAI Inc., Wheeling.

The Lunar Observer/May 2020/ 36