September 2020 the Lunar Observer by the Numbers

Home , Carrel (crater), Demonax (crater), De La Rue (crater), Keldysh (crater), Lacus Temporis, Rupes Cauchy

A publication of the Lunar Section of ALPO Edited by David Teske: [email protected] 2162 Enon Road, Louisville, Mississippi, USA Back issues: http://www.alpo-astronomy.org/ September 2020 In This Issue Check out 2020 ALPO Conference Announcement 2 Lunar Calendar August 2020 3 the ALPO An Invitation to Join ALPO 3 Observations Received 4 Virtual By the Numbers 6 Conference Submission Through the ALPO Image Achieve 7 When Submitting Observations to the ALPO Lunar Section 8 Page 2 Call For Observations Focus-On 8 Focus-On Announcement 9 Little Brother, R. Hill 10 Taruntius, Craters, Domes and Many Rilles, D. Teske 11 Another Dream Bridge in the Shore of Mare Crisium, A. Anunziato 12 Online readers, North of Brahe, R. Hill 15 click on images Carrel, a Copernican Crater in Mare Tranquillitatis, A. Anunziato 16 for hyperlinks The Ends, R. Hill 17 Detection and Identification of Two Rille-like Features South of Crater Linnè G. R. Lena and KC Pau 18 From Philosopher to Bay of Rainbows, R. Hill 24 The Lunar 100, A. Anunziato 25 Focus-On, Lunar Targets 21-30, J. Hubbell 26 Recent Topographic Studies 48 Pico, R. H. Hays, Jr. 60 Messier and Messier A, R. H. Hays, Jr. 64 Silberschlag and Rima Ariadaeus, R. H. Hays, Jr. 80 Ariadaeus and Sosigenes A, R. H. Hays, Jr. 81 Lunar Geographic Change Detection Program, T. Cook 110 Key to Images in this Issue 118

Warm greetings to all. This issue marks my first year of editing The Lunar Observer. It amazes me all the high quality lunar work that is sent in for publication. Thanks much! In this issue, Jerry Hubbell features Lunar targets 21-30 in his Focus-On series. As has been the past few months, this Focus-On is wildly popular with lunar observers. Also, Raffaello Lena and KC Pau discuss a newly imaged lunar rille, Rik Hill continues on his survey of interesting lunar targets, Robert H. Hays, Jr. contributes four articles with drawings of the Focus-On topics, David Teske explores a dynamic lunar terrain and Tony Cook investigates Lunar Geologic Change. All this plus many great lunar images from around the world.

Be sure to check out the virtual ALP conference on the next page. Dates are October 2-3, 2020! Be safe and healthy out there. The Lunar Observer/September 2020/ 1

2020 ALPO Conference Announcement

Due to the continuing nearly worldwide quarantining caused by the Corovid-19 pandemic and a possible second wave of in- fections, the ALPO board of directors has voted to follow the example of many other organizations and will hold the 2020 ALPO Conference online via Zoom, the web conferencing software now commonly used for audio and/or video meetings and other such gatherings.

The dates will be Friday and Saturday, October 2 and 3, 2020. The conference will also be Live Streamed on the ALPO YouTube channel.

As a "virtual" event, this year's ALPO conference will NOT be an in-person event at the University of North Georgia as origi- nally planned. This way, you can participate from the comfort of your own home or office.

The conference times for both days will be from 10 a.m. to 2 p.m. Pacific Time (1 p.m. to 5 p.m. Eastern Time) and allow for seven paper presentation sessions each day. All presentations be limited to approximately 15 minutes each with a few minutes left for audience questions.

The ALPO board of directors meeting will be held on Friday, October 2, at 4 p.m. PT (7 p.m. ET). The ALPO Conference is open to anyone to attend, however, all presenters must be current members of the ALPO. Digital memberships start at only $18 a year. To join online, go to http://www.astroleague.org/store/index.php?main_page=product_info&cPath=10&products_id=39, then scroll to the bottom of that page, select your membership type, click on "Add to Cart" and proceed from there.

Following a break after the last paper presentation on Saturday afternoon, October 3, will be presentation of the annual Walter Haas Observer Award. This will be followed by our keynote speaker at 4 p.m. PT (7 p.m. ET). With the award presentation and keynote speech usually occurring at the traditional Saturday evening dinner, we suggest that you enjoy your own meal during these last two conference events. The only hardware required along with your computer are a webcam and microphone. If you will be using a laptop computer, both are already built in to your system. Those with desktop computers can obtain an inexpensive webcam with built-in microphone from either your local computer retailer or online. Then familiarize yourself with their operation now so you are comfortable with enabling and disabling the video and muting and unmuting the microphone in time for our conference.

All attendees must already have Zoom installed on their computer prior to the conference dates. Zoom is free and available at https://zoom.us/

The Zoom links will be posted on social media and e-mailed out to those who wish to receive it that way on Thursday, Octo- ber 1. There will be a separate Zoom meeting set up for each day. The Zoom virtual (online) meeting room will open 15 minutes prior to the beginning of each day’s activities.

Participants are encouraged to submit research papers, presentations and experience reports concerning various aspects of Earth-based observational solar system astronomy. Suggested topics for papers and presentations include the following: • New or ongoing observing programs and studies, specifically, how those programs were designed, implemented 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, observing conditions, the SpaceX "Starlink" artificial satellite program, etc. Those individuals wishing to present a paper should submit their request to Tim Robertson at [email protected] no later than Monday, September 21, along with a brief bio and summary of their presentation. Microsoft PowerPoint is the preferred method of visual presentation along with an audio explanation.

A follow-up announcement to this one will be issued soon with more details as they develop.

The Lunar Observer/September 2020/ 2

Lunar Calendar September 2020

Date Time UT Event 2 0522 Full Moon 3 North limb of Moon most exposed +6.5o 6 0500 Mars 0.03o south of Moon, occultation NE S. America to Europe 6 0600 Moon at apogee, 405,607 km 10 0926 Last Quarter Moon 11 1300 Moon 0.3o south of M35 12 Moon at greatest northern declination 24.3o 13 West limb most exposed -7.2o 14 0500 Venus 5o south of Moon 17 1100 New Moon, lunation 1209 17 South limb of Moon most exposed -6.5o 18 1400 Moon at perigee 359,082 km 24 0155 First Quarter Moon 25 0700 Jupiter 1.6o north of the Moon 25 2100 Saturn 2o north of Moon 25 Moon at greatest southern declination -24.4o 25 East limb of the Moon most exposed +7.1o

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/September 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://www.alpo-astronomy.org/

Observations Received

Name Location and Organization Article/image Alberto Anunziato SLA-LIADA, Paraná, Argentina Paraná, Ar- Article and images Another Dream gentina Bridge in the Shore of Mare Crisium, The Lunar 100, Carrel, A Copernican Crater in the Mare Tranquillitatis, drawing of Aristarchus, drawing of Ar- istarchus, images of Mare Frigoris (2) and Archimedes. Jorge Arranz Lunar Group of the Madrid Astronomical As- Drawings of Rimae Ariadaeus and sociation (AAM) Schiller. Sergio Babino SAO-LIADA, Montevideo, Uruguay Image of Fracastorius (3), Aristarchus (2), Mare Frigoris (3), Hipparchus and Schiller. Ciro Barbero Rosario, Argentina Drawing of Hyginus and Archimedes. Juan Manuel Biagi SLA-LIADA, Paraná, Argentina Image of Schiller. Borgatello Alaniz, Aylen AEA - Oro Verde, Entre Rios, Argentina Images of Aristarchus (2). Francisco Alsina Cardinalli SLA-LIADA, Oro Verde, Argentina Images of Fracastorius, Aristarchus (4), Pico (3), Hyginus, Messier (6), Mare Frigoris (4), Archimedes (2), Hippar- chus (2), Rimae Ariadaeus (2) and Schiller. Jeffrey Carels Belgium Image of Plato. Jairo Chavez SLA-LIADA, Popayán, Colombia Images of Aristarchus (3), Hyginus and Plato Walter Ricardo Elias AEA - Oro Verde, Entre Rios, Argentina Images of Censorinus, Dionysius, Heli- con, Messier, Moretus, Sharp, the Moon, Plato, Aristarchus (6), the wan- ing crescent Moon, Tycho, Pythagoras, Menelaus, Manilius (2), Furnerius, Car- penter (2), Copernicus, Eudoxus, Sinus Iridum, Stevinius and Tycho. Howard Eskildsen Ocala, Florida, USA Images of Mare Orientale (3), Wargen- tin and Moretus. César Fornari Observatorio Galileo GalileI, Oro Verde, Ar- Image of Hyginus. gentina Desiré Godoy SLA-LIADA, Oro Verde, Argentina Images of Messier, Hipparchus and Ri- ma Ariadaeus. Martín Queirolo Gomez SAO-LIADA, Montevideo, Uruguay Images of Mare Frigoris, Archimedes and Schiller. Marina Lorena Grandolio AEA - Oro Verde, Entre Rios, Argentina Images of Censorinus, Dionysius and Aristarchus. Marcelo Mojica Gundlach LIADA-Cochabamba, Bolivia Images of Hyginus (2), Mare Frigoris (2), Archimedes and Rimae Hippalus.

The Lunar Observer/September 2020/ 4

Lunar Topographic Studies

Observations Received

Name Location and Organization Article/image Robert H. Hays, Jr. Worth, Illinois, USA Drawings and articles of Pico, Messier and Messier A, Silberschlag and Rima Ariadaeus and Ariadaeus and So- sigenes A. Rik Hill Tucson, Arizona, USA Image and article Little Brother, The Ends, From Philosopher to the Bay of Rainbow and North of Brahe. Jerry Hubbell Wilderness, Virginia, USA Article Focus-On Lunar 21-30. Gabriel Andres Jaimes Illanes Cochabamba, Bolivia Image of the Moon, Jupiter and Saturn. Raffaello Lena Italy Article and images Detection and Iden- tification of Two Rille-like Features South of Crater Linnè G. KC Pau Hong Kong Article and images Detection and Iden- tification of Two Rille-like Features South of Crater Linnè G. Gabriel Re AEA - Oro Verde, Entre Rios, Argentina Image of Aristarchus. Pedro Romano SLA-LIADA, San Juan, Argentina Image of Fracastorius,. Leandro Sid AEA - Oro Verde, Entre Rios, Argentina Images of Aristarchus, Waxing Gib- bous Moon, Marius, Vieta, Agrippa, Godin, Mare Crisium, First Quarter Moon (2), Alphonsus (2), Biot and Fra- castorius (3). David Teske Louisville, Mississippi, USA Article and image Taruntius, Craters, Domes and Many Rilles. Román García Verdier Paraná, Argentina. Images of Proclus and Hipparchus. Fabio Verza SNdR Luna UAI, Milan, Italy Images of the First Quarter Moon, Al- bategnius, Agrippa, Aristoteles, Manili- us, Aristillus, Montes Apenninus, Mul- ler, Archimedes, Clavius, Eratosthenes, Copernicus(2), Longomontanus, Pro- clus, Rupes Recta, De LaRue, Macrobi- us, Mare Nectaris (2), Atlas, Anaxago- ras, Messier (2), Pythagoras, the wan- ing crescent Moon, the waxing crescent Moon (4), Demonax (2), Atlas, Janssen, Mare Crisium, Darryl, Wilson Marshall, Virginia, USA Images of Tycho’s central peak.

The Lunar Observer/September 2020/ 5

September 2020 The Lunar Observer By the Numbers

This month there were 175 observations by 28 observers from 8 countries.

Obsvers per Country and Number of Observations for the September 2020 The Lunar Observer 100

Number of observers Number of Observations

The Lunar Observer/September 2020/ 6

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 for- mat, 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/September 2020/ 7

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 required. 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 November 2020 edition will be the Lunar 100 numbers 31-40. 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 31-40 article is October. 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 31-40) November 2020 October 20, 2020 Lunar 100 (numbers 41-50) January 2021 December 21, 2020

The Lunar Observer/September 2020/ 8

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 31-40 will be featured in the November 2020 The Lunar Observer. Submissions of articles, drawings, images, etc. due by October 20, 2020 to David Teske and Jerry Hubbell.

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 rille & 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

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 Jerry Hubbell –[email protected] David Teske – [email protected]

The Lunar Observer/September 2020/ 9

Little Brother Rik Hill

Outshone by his big brother Copernicus, seen here in the lower left, the sizable crater Eratosthenes (diameter 60 km) is nevertheless a very interesting crater with nicely terraced walls, a good central peak cluster and a tight herringbone ejecta ta blanket surrounding the crater. Seen here, Eratosthenes forms a southern anchor of Montes Apenninus. Between Eratosthenes and Copernicus is an eye-catching string of secondary craters from the Copernicus impact event. It takes at least a 3-inch telescope to make them out clearly at the right lighting. At the south end of this string is a large ghost crater Stadius (70 km) which stands between Sinus Aestuum to the east (southeast of Eratosthenes) and Mare Insularum below Copernicus to the southwest.

At the opposite side of Eratosthenes from Stadius is another ghost crater sitting out in Mare Imbrium. This is Wallace (27 km) with a more complete rim on the west side than the east. Notice the twin satellite craters below it, Eratosthenes A and B (6 and 5 km respectively), small craters to be sure but nowhere near the limit for this image!

Eratosthenes, Richard Hill, Tucson, Arizona. 03 April 2020 02:24 UT, colongitude 28.8o. Dynamax 6 inch Schmidt- Cassegrain telescope, 1.5 x barlow, 610 nm filter, Skyris 445M camera. Seeing 7-8/10.

The Lunar Observer/September 2020/ 10

Taruntius, Craters, Domes and Many Rilles David Teske

The large impressive crater on the northern terminator of this image is Taruntius, a 56 km diameter crater that lies southeast of Mare Crisium. It has a concentric wall, typical of a floor-fractured crater. Cameron is the 11 km diameter, crisp crater on the northwest wall of Taruntius. The ramparts of Taruntius look most spectacular in the light of lunar sunset. West of Taruntius is the 12.4 km diameter crater Cauchy, stuck between Rima Cauchy to its north and Rupes Cauchy to its south. Just south of Rupes Cauchy are two beauti- ful domes. Cauchy ω is the dome farthest right (east) and has a tiny but visible summit craterlet. Cauchy τ is to the left (west) and is similar in size to Cauchy ω. Farther west, it looks like there may be several smaller domes, but the lighting there is more direct, so the domes do not show as well as ω and τ.

South of Taruntius are the very familiar craters Messier and Messier A with their comet-like tail. Messier is the eastern (right) of the crater pair, 9 by 11 km in size. Just west of this is Messier A 13 by 11 km. It is amazing to imagine that long ago, as asteroid blasted into the Moon at such a shallow angle as to blow out both of these craters and then send rays downrange. At sunset, the rays of Messier A can be seen crossing an unnamed dorsum in western Mare Fecunditatis. Just northwest of the Messier twins is Rima Messier, a thin rille whose age I can not de- termine, as it is not crossed by the rays of Messier. Note also in western Mare Fecunditatis several ghost craters that were flooded by the lavas that flooded this area over three billion years ago and some small swellings. Domes perhaps?

Farther south at the bottom of this image is the crater Gutenberg (74 km), partially cut off. A cleft is inside this crater. Running north- northwest of Gutenberg is Rimae Goclenius, a system of wide rilles 240 km long along the western reaches of Mare Fecunditatis. The Rimae Gutenberg is a system of rilles stretching 330 km northwest of Gutenberg on the highland material between Mare Fecunditatis and Sinus Asperitatis.

Taruntius, David Teske, Louisville, Mississippi, USA. 07 August 2020 0934 UT, colongitude 128.5o. 180 mm Takahashi Mewlon telescope, ZWO ASI 120 mm/s camera, IR block filter, 500 frames, Firecapture, Registax, Photoshop. Seeing 7/10.

The Lunar Observer/September 2020/ 11

Another Dream Bridge in the Shore of Mare Crisium Alberto Anunziato

Two years ago, in an image of the northwest shore of Mare Crisium that we had taken because the illumination allowed us to observe the radial dorsa, I thought I had found the famous "O'Neill's Bridge", in which were two bright strips that link two mountain ranges parallel to the contour of Mare Crisium (image 1). In image 2 we see the detail of image 1. I was so sure that I had found the elusive pareidolia that had generated a heated debate in the middle of the last century, that a year ago I showed it to my daughter Atina, before beginning my night observation, as a way of reflecting on the transience of what we see on the Moon: "we only see this bridge today, perhaps for a few hours, then we will have to wait for four weeks, and only if there will be no clouds", I told him, after telling him the story of the dream bridge on the Moon. But I was wrong. When I began to carefully read the story of O'Neill's observation, I realized that what I had seen ran from east to west and not from north to south. For a day I was looking at the images of the northwest shore of Mare Crisium that I had, intrigued to reveal the cause of that strange illumination. At least I knew, thanks to the fact that I saw it with my daughter on another occasion, that it was repeated. Luckily, I had recorded in my logbook the time of the observation (02.55 UT -18-8-19), which allows us to compare the colongi- tudes of the two observations: 120.6º and 120.5º. In image 3, with very different illumination, we see that in the gorge (this time illuminated) there is a small mountain range with two peaks (detail in image 4). This mountain range explains the western section of the “Atina’s Bridge” (to give it a name, I name it after my 10 -year-old daughter), but it does not explain the eastern section of the inverted “V” (on the right) that can be seen in the images 1 and 2, as there is no visible accident that can cause the pareidolia of a bridge. In image 5 (from the QuickMap of the Lunar Reconnaissance Orbiter) we see the area in detail and we observe that the eastern section of the “Atina’s Bridge” is due to a very small mountain range that runs parallel to the much higher mountain range that makes up the western section. The interesting thing is that both mountain ranges located in the gorge are widely separated from each other, but when they are the only accidents illuminated by sunlight, their combined brightness recreates the shape of a bridge. We invite the reader to observe at 120º colongitude, and we assure you that visually it is even more distinguishable than in the images.

Figure 1, Peirce, Alberto Anunziato, Oro Verde, Argentina. 03 February 2018 05:48 UT. Celestron CPC 11 inch Schmidt –Cassegrain telescope, Canon Eos Digital Rebel XS camera.

The Lunar Observer/September 2020/ 12

Figure 2, Peirce, Alberto Anunziato, Oro Verde, Argentina. 03 February 2018 05:48 UT. Celestron CPC 11 inch Schmidt – Cassegrain telescope, Canon Eos Digital Re- bel XS camera. Close-up of Figure 1.

Figure 3, Proclus, Román García Ver- dier, Paraná, Argentina. 15 September 2019 03:44 UT. 180 mm Newtonian Re- flector telescope, QHY5-II camera.

Online readers, click on images for hyperlinks

The Lunar Observer/September 2020/ 13

Figure 4, Proclus, Román García Verdier, Paraná, Argentina. 15 September 2019 03:44 UT. 180 mm Newtonian Reflector telescope, QHY5-II camera. Close up of Figure 3.

Figure 5, Atina’s Bridge, LRO.

The Lunar Observer/September 2020/ 14

North of Brahe Rik Hill

Center bottom we have the spectacular crater Tycho (diameter 88 km), the center of the largest ray system on the Moon completely wraps around the globe. This is two days after the terminator passed over this crater and already the Sun is high enough to show the rays without washing out some of the topographic details. For orientation purposes, the large dark crater at the top is Pitatus. Just below that are two similar sized craters, Gauricus (82 km) on the right and Wurzelbauer (90 km) and off to the right is a much smaller well-defined crater with a fairly dark patchy floor, Hell (34 km). To the left of Pitatus and you’ll see one of the better double walled craters on the Moon, Hesiodus A (15 km) looking like a bulls-eye target with the small central peak. The parent crater Hesiodus (44 km) is above it with a small 5 km central crater.

Going back to Tycho, we can see one of the larger rays radiating out from the crater about 10 o’clock right off the upper left corner of the image. If you look carefully close in to Tycho you will see a fine trail of secondary craters following along one edge of that ray. This takes some good seeing to spot by eye. Off to the upper right of Tycho you can see a radial spray of fine rays out to the edge of the image. During full Moon you can see these rays wrap around the whole body even in a pair of binoculars.

Tycho, Richard Hill, Tucson, Arizona. 05 April 2020 04:15 UT, colongitude 53.3o. Dynamax 6 inch Schmidt- Cassegrain telescope, barlow, 610 nm filter, Skyris 445M camera. Seeing 7-8/10.

The Lunar Observer/September 2020/ 15

Carrel, a Copernican Crater in the Mare Tranquillitatis Alberto Anunziato

Carrel, formerly Jansen B, is a Copernican crater located north of Mare Tranquillitatis. When looking near the terminator (colongitude 337.8º) the intricate details of the surroundings of Carrel are observed. To the north of Carrel is a peak high enough to cast shadow and to the south are a series of ridges that run east to west. Each of these ridges is different from the others, the last one to the west is the highest (if we judge its height by the shadow it casts) and the last one to the east is the longest, since its shadow is thin but we see details that we do not see in the others, a bright part near the ground and the rest with a less diffuse brightness. This series of ridges are surely the remains of a crater submerged by the lava of the Tranquillitatis mare, so Carrel would be a crater formed on another crater. The interior of the crater is completely covered in shadows, so we don't distinguish the details of what we know to be an intricate Copernican interior. What we do observe is that the west wall is clearly brighter than the rest, as if it were higher. When I looked for information about Carrel, I remembered the front page of “The Lunar Observer” of November 2017, in which Robert H. Hays splendidly drew our crater in a different illumination. What Hays calls a "rounded protrusion" on the eastern side is clearly seen in our image. When I looked at the edge of Carrel, its slopes could be presumed to be high and extensive, from the diffuse brightness that contrasted with the much stronger brightness of the west slope, probably more vertical.

Carrel, Alberto Anunziato, Paraná, Argentina. 25 July 2020 23:00-23:25 UT. Meade EX 105 Maksutov-Cassegrain telescope, 154 x.

The Lunar Observer/September 2020/ 16

The Ends Rik Hill

Normally a more foreshortened feature, at this libration we get a good look at Endymion, the large 125 km diameter crater just right of center. As lunar night approaches we see the wonderful shadows crawling across the floor. The two large craters below and to the west (left) are Atlas (90 km) and the smaller, young- er Hercules (71 km) with the satellite crater Hercules G 13 (13 km) on its floor. Many observers think these two are much alike but actually they are remarkably different with a smooth flat floor in Hercules and rimae, and roughness on the floor of Atlas. Even the ejecta is very different with Atlas having a thick ejecta blanket that even covers over a much older crater to he north. Above these two is the teardrop shaped crater Keldysh (34 km). Below and to the right of Atlas is a ghost crater seen best at this Sun angle, Chevallier (54 km), with small satellite crater Chevallier B (13 km) contained within its walls. To the right of Chevallier is a flat figure-8 shaped area that is Lacus Temporis some 257 km long.

Another smaller mare-like region that lies north of Endymion is unnamed. North of this region is a hard to trace, ruined crater De La Rue with a 14 km crater in the middle De La Rue J. On its north wall are a couple more craters, Strabo (56 km) and to its left Thales (32 km). At the top of this image is a rather polygonal crater Democritus (41 km) and below it another large ghost crater, Gartner (105 km) opening onto eastern- most Mare Frigoris similar to Fracastorius but a much weaker copy. So, one way you can remember the layout is that one END of Mare Frigoris you find ENDymion!

Endymion, Richard Hill, Tucson, Arizona. 06 August 2020 07:24 UT, colongitude 121.1o. Dynamax 6 inch Schmidt- Cassegrain telescope, 2 x barlow, 665 nm filter, Skyris 132M camera. Seeing 7-8/10.

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Detection and Identification of Two Rille-like Features South of Crater Linnè G. Raffaello Lena and KC Pau

Introduction and observations When Pau processed an image of Montes Caucasus, taken on 1 March 2020 at 11h33m UT, Colong 350o with his 250mm f/6 Newtonian reflector, like every other lunar amateur, the focus was on the mountains and the nearby Valentine dome. All of a sudden, a faint dark streak, south of crater Linné G, flashed into his eyes. Scanning this area carefully, Pau could surely confirm the streak was not an artifact. It was really lying there. Later, he compared the image with the LROC QuickMap (http://target.lroc.asu.edu/da/qmap.html). The same location shows faintly a delicate dark line (fig. 1).

Fig. 1: Image made by Pau (left). The dark streak is marked with white lines. Cropped image from LROC QuickMap (right). Pau sent both his own image and that of the QuickMap to Prof. Leatherbarrow of BAA lunar section for his advice. His response was it looked a tiny rille. The resolution of the image is not so good that no one can confirm the streak is a real rille. Recently, Pau worked through his archive of lunar images and he found one image that had better resolution of the dark streak. In this image the streak looks really like two rilles. It is not a single rille but two rilles that run parallel to each other (fig.2). The image was taken on 11 September 2017 at 21h05m UT, Colong 162o. Equipment used is same as the previous image, with a 2.5X barlow and a QHYCCD290M planetary camera. Pau sent the latest image to Prof. Leatherbarrow for his advice. He advised to contact Raffaello Lena for further analysis and interpretation. In fact the examined features do not really show up as such on QuickMap elevation profiles and 3D modelling. Many rilles existing on the surface of the near-side Moon have been created by volcanism and tectonism. Some lunar rilles need an appropriate illumination condition to identify them, such as the Rima Sheep- shanks. In this preliminary note we examine these two rilles-like features using the LOLA DEM data set and the LTVT software package. Finally the Chandrayaan-1 M3 data set were used to derive spectra that highlight mineralogical characteristics of lunar volcanic materials.

The Lunar Observer/September 2020/ 18

Fig. 2: Images made by Pau as described in the text. In the image taken on 11 September 2017 two rilles-like features run parallel to each other. Rendered Images of the examined rilles-like features based on LOLA DEM Generating an elevation map of a part of the lunar surface requires its three-dimensional (3D) reconstruc- tion. Recently, a global lunar digital elevation map (DEM) obtained with the Lunar Orbiter Laser Altimeter (LOLA) instrument on the Lunar Reconnaissance Orbiter (LRO) spacecraft has been released. A synthetic image of the lunar surface can be generated based on an available DEM as seen from a given direction for lighting from some other specified direction. The LTVT software by Mosher and Bondo was used to generate synthetic view of selected parts of the LOLA DEM.

A rendered image displays the shadow length cast by a dome and or a crater and is useful for simulating par- ticular situations, showing how rapidly the appearance of these features changes with increasing solar elevation. LOLA DEM was thus used for rendered images with different solar illumination angle, which show the examined structures at times of 3h00m UT, 5h00m UT, 8h00m UT and 11h30m UT respectively of the same day of the first image of Pau (cf. Figs. 3-6). The simulation effectively displays two rilles that run parallel to each other (termed R1 and R2 and marked with white lines).

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Fig. 3: Rendered image based on the LOLA DEM using LTVT for 1 March 2020 at 03h00m UT.

Fig. 4: Rendered image based on the LOLA DEM using LTVT for 1 March 2020 at 05h00m UT.

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Fig. 5: Rendered image based on the LOLA DEM using LTVT for 1 March 2020 at 05h00m UT.

Fig. 6: Rendered image based on the LOLA DEM using LTVT for 1 March 2020 at 011h30m UT.

The Lunar Observer/September 2020/ 21

Thus, the rendered images based on LOLA DEM indicates the real presence of these elusive features: they are clearly detectable under a strongly oblique solar illumination angle (about 1° see Fig. 4). Spectral Analysis M3 is an imaging reflectance spectrometer that can detect 85 channels between 460 to 3000 nm, and has a spatial resolution of 140 or 280 meters per pixel. Data have been obtained through the M3 calibration pipe- line to produce reflectance with photometric and geometric corrections using image set taken during the op- tical period OP1B. A continuum removal method that enhances the features in the 1000 nm absorption band and more accurately shows the position of the band centre has been used fitting a straight line between 750 and 1500nm to remove the continuum (Fig. 7).

Fig. 7: Moon Mineralogy Mapper (M3) spectra of the examined features (rille poin 1 and point 2 at 35.49° N 13.06° E and 35.44° N 13.15° E) and the mare unit (35.50° N 13.72° E). The spectra of the two point of the rille R2 (Fig. 7) displays a narrow trough around 1000nm with a minimum wavelength at 960nm and an absorption band at around 2000nm, corresponding to a typical pyroxene signature, indicating a basaltic composition. Fig. 7 also display the spectrum of the mare unit (35.50° N 13.72° E) with similar absorption bands, demonstrating the basaltic composition of the examined features described in the current article. Summary and Conclusion Our data show very clearly there are two long and elusive rilles-like features oriented roughly radially with respect to Mare Imbrium. There are small craters present on both rilles floor (from LROC WAC imagery), which suggests that the “rilles” are older than these superposing craters. R1 and R2 looks like degraded old structures, rilles-like feature or valley, which deserve further investigation and imagery. We encourage more high-resolution imagery of this area so we can have more data to identify their shape and size. Please check also your past imagery and send them to us for the ongoing study. It once again shows that with today imaging technology, there is still a chance for amateurs to study elusive features on the moon. In combination with high-resolution images, such investigations might greatly extend our present knowledge of the processes occurred on the Moon.

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References [1] Basaltic Volcanism Study Project, 1981. Basaltic Volcanism on the Terrestrial Planets. New York: Pergamon Press. http://ads.harvard.edu/books/bvtp/

[2] Besse, S., J. M. Sunshine, and L. R. Gaddis (2014), Volcanic Glass Signatures in Spectroscopic Survey of Newly Proposed Lunar Pyroclastic Deposits, Journal of Geophysical Research - Planets, Vol. 119, doi:10.1002/2013JE004537.

[3] Green, R.O., et al., 2011. The Moon Mineralogy Mapper (M3). Imaging Spectrometer for Lunar Sci- ence. Journal of Geophysical Research – Planets, Vol. 116, E10. Available at: https://doi.org/10.1029/2011JE003797

[4] Mosher, J., & Bondo, H., 2006. Lunar Terminator Visualization Tool (LTVT). See: https://github.com/ fermigas/ltvt/wiki

[5] Scholten, F., Oberst, J., Matz, K. D., Roatsch, T., Wählisch, M., Speyerer, E. J., Robinson, M. S., (2012). GLD100: The Near-global Lunar 100 m Raster DTM from LROC WAC Stereo Image Data. Journal of Geophysical Research, Vol. 117 No. 3 (E00H17). doi:10.1029/2011JE003926

[6] Smith et. al. (2010). The Lunar Orbiter Laser Altimeter Investigation on the Lunar Reconnaissance Or- biter Mission. Space Science Reviews Vol. 150: pp. 209-241, doi:10.1007/s11214-009-9512-y.

The Lunar Observer/September 2020/ 23

From the Philosopher to the Bay of Rainbows Rik Hill

When Sinus Iridum, or the Bay of Rainbows, is on the terminator it always draws you in. This half flooded 411 km diameter crater is breathtaking when the mountains on the west side, the Montes Jura, catch the morning sunlight ion their 6 km high peaks. The crater on the north side of these mountains is Bianchini (39 km) filled with shadow but the rim is well shown. The two cusps of this mountainous arc are Promontorium Heraclides (height 1700 m) as the south point and Promontorium Laplace (2600 m) north casting a nice shadow. Two similar sized craters sit outside the mouth of the bay like a couple of sentinels. Helicon (26 km) is on the left and Le Verrier (20 km) is on the right. Below them forming a rough equilateral triangle is the crater Helicon B (6 km). To the right of this near the edge of the nameplate of this image is the small crater Le Verrier A (4 km).

Moving up from P. Laplace we see a large isolated range of mountains, Montes Recti (88 x 19 km) rising 1.8 km above the surrounding plains of Mare Imbrium. A little farther on you see a scattering of mountains. These are Montes Teneriffe ending with the isolated Mons Pico (2.4 km) on the right end. Above these mountains is the crater Plato (104 km). Coming out on the right side you can see the largest of the Rimae Plato. Above Plato is a long flat area. This is Mare Frigoris stretching nearly 2000 km from the crater Harpalus just behind Sinus Iridum (in shadow here) all the way to Atlas and Hercules. Before leaving notice the subtle shadings on the floor of Mare Imbrium. These are well shown with the deep red filter used here.

Sinus Iridum to Plato Richard Hill, Tucson, Arizona. 04 April 2020 04:20 UT, colongitude 43.1o. Dynamax 6 inch Schmidt-Cassegrain telescope, 2 x barlow, 665 nm filter, Skyris 445M camera. Seeing 7-8/10.

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Lunar 100 Alberto Anunziato

When “The Lunar Observer” announced the objective of its “Focus on” Section for the month of May 2020: images of the selenographic accidents included in the famous Lunar 100 list, in the Sociedad Lunar Argenti- na (SLA) and Sociedad Astronómica Octante (SAO) of the República Oriental del Uruguay, we consider it an interesting opportunity to join this initiative. To generate enthusiasm in the amateur lunar observers, we launched, with a little daring, our Lunar Program 100, under the auspices of the Lunar Section of the Liga Iberoamericana de Astronomía (LIADA). The opportunity was twofold: add observers who were encouraged to collaborate with an observation program and review the images in our archive. It was a joy to receive images from 23 observers from 5 countries. Up to number 30 of Lunar 100 we have received almost 200 images. The objective was also twofold, to report the images to "The Lunar Observer" and to publish them in all the media of the SLA, SAO and the Lunar Section LIADA. The result of this was a special issue of "El mensajero de la Luna" (the SLA newsletter) with the images corresponding to the first ten numbers of the Lunar 100 along with explanatory texts for each of them. It is also an interesting opportunity to learn about lunar geology by reviewing old images. It is true that our images have a bias, which we recognized when selecting the images, since they correspond mainly to the lunar features observed in the framework of the "Project for the Verification/Elimination of Past Transient Lunar Phenomena Reports" (ALPO/BAA/ University of Aberystwyth), with whom we have collaborated for five years now, led by Tony Cook, a true mentor to all of us who make up our group.

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Features 21 through 30

Jerry Hubbell Assistant Coordinator, Lunar Topographical Studies

This is the third 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 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 limited 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 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. 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. Here is a list of features 21 – 30:

L Feature Name Significance Rükl Chart 21 Fracastorius Crater with subsided and fractured floor 58

22 Aristarchus Plateau Uplifted region with pyroclastics 18 23 Pico Isolated Imbrium basin-ring fragment 11 24 Hyginus Rille Rille containing rimless collapse pits 34

25 Messier and Messier A Oblique ricochet-impact pair 48 26 Mare Frigoris Arcuate mare of uncertain origin 2-6

27 Archimedes Large crater lacking central peak 12, 22 28 Hipparchus First drawing of a single crater 44, 45

29 Ariadaeus Rille Long, linear graben 34 30 Schiller Possible oblique impact 71

Table 1. The Third Set of 10 Lunar 100 Features

The Lunar Observer/September 2020/ 26

The Lunar 100: Feature 21-Fracastorius

Figure 1. Fracastorius, Sergio Babino SAO-LIADA, Montevideo, Uruguay, 14 March 2020, 04:59 UT, Colongitude 146.8°, 203-mm SCT, ZWO 174mm CMOS camera North/Right, East/Up.

The Lunar Observer/September 2020/ 27

The Lunar 100: Feature 21-Fracastorius

Figure 2. Fracastorius, Jerry Hubbell, Locust Grove, VA USA, 27 June 2009 01:30 UT, Colongitude 323.7°, 120 mm. ED APO Refractor f/7.5, ATIK 314E CCD Camera, North/Up, East/Right.

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The Lunar 100: Feature 22-Aristarchus Plateau

Figure 3. Aristarchus Plateau, Luis Francisco Alsina Cardinalli SLA-LIADA, Oro Verde, Argentina, 12 December 2016, 00:48 UT, Colongitude 65.2°, 200-mm Meade Starfinder 8, Astronomic ProPlanet 742 IR-Pass Filter, CCD camera, North/Down, East/Left.

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The Lunar 100: Feature 22-Aristarchus Plateau

Figure 4. Aristarchus Plateau, Jerry Hubbell, Locust Grove, VA USA, 07 January 2012, 00:56 UT, Colongitude 356.2°, 127 mm APO Refractor + 4x PowerMate, DMK21AU04.AS video camera. North/Up, East/Right.

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The Lunar 100: Feature 23-Mons Pico

Figure 5. Mons Pico, Francisco Alsina Cardinalli SLA-LIADA, Oro Verde, Argentina, 20 December 2015, 02:06 UT, 250-mm SCT Meade LX200, Canon Eos DSLR camera. Colongitude 21.4°, North/Up, East/Right.

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The Lunar 100: Feature 23-Mons Pico

Figure 6. Mons Pico, Francisco Alsina Cardinalli SLA-LIADA, Oro Verde, Argentina, 20 August 2018, 23:34 UT, 200-mm Refractor, QHY5-II camera. Colongitude 26.2°, North/Up, East/Right.

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The Lunar 100: Feature 24 Hyginus Rille

Figure 7. Hyginus Rille, Marcelo Mojica Gundlach LIADA, Cochabamba, Bolivia, 30 April 2020, 23:37 UT, Colon- gitude 9.4°, 152-mm Maksutov,ZWO ASI 178 Camera, Seeing:7/10, Transparency:5/6 North/Up, East/Right

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The Lunar 100: Feature 24-Hyginus Rille

Figure 8. Hyginus Rille (Drawing) Ciro Barbero, Rosario, Argentina, 17 September 2018, 23:00 UT. Colongitude 7.8°, 6-inch (152 mm) Reflector, 150x eyepiece, North/Up, East/Right.

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The Lunar 100: Feature 25– Messier and Messier A

Figure 9. Messier & Messier A, Francisco Alsina Cardinalli (SLA-LIADA, Oro Verde, Argentina, 21 August 2016 05:01 UT, Colongitude 129.6°, 250-mm SCT (Meade LX200), QHY5-II Camera. North/Up, East/Right.

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The Lunar 100: Feature 25-Messier and Messier A

Figure 10. Messier & Messier A, Desiré Godoy (SLA-LIADA, Oro Verde, Argentina, 08 November 2019 01:20 UT, Colongitude 40.7°. 200 mm Newtonian, QHY5-LII-M camera, North/Up, East/Right.

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The Lunar 100: Feature 26-Mare Frigoris

Figure 11. Mare Frigoris, Alberto Anunziato SLA-LIADA, Oro Verde, Argentina, 10 September 2016 23:12 UT. Colongitude 22.9°, 279 mm f/10 Celestron Edge HD SCT, QHY5-II camera, North/Up, East/Right.

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The Lunar 100: Feature 26-Mare Frigoris

Figure 12. Mare Frigoris, Sergio Babino (SAO-LIADA, Montevideo, Uruguay, 14 March 2020, 04:46 UT, Colongi- tude 146.2°, 203 mm SCT, ZWO 174 mm Camera. North/Left, East/Up.

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The Lunar 100: Feature 27-Archimedes

Figure 13. Archimedes, Jerry Hubbell, Locust Grove, VA, 20 March 2011 02:37 UT, Colongitude 94.8°, 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 27-Archimedes

Figure 14. Archimedes, Marcelo Mojica Gundlach, Cochabamba, Bolivia, SLA, 05 January 2020, 22:53 UT, Colon- gitude 36.7°, 6-inch Maksutov SkyWatcher FL=1800 mm, ZWO ASI178. Seeing 5/10, Transparency 5/6, North/Left, East/Up.

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The Lunar 100: Feature 28-Hipparchus

Figure 15. Hipparchus (highlighted), Sergio Babino (SAO-LIADA, Montevideo, Uruguay, 05 December 2019, 01:10 UT, Colongitude 21.2°, 250-mm SCT, ZWO 174 mm camera, North/Up, East/Right.

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The Lunar 100: Feature 28-Hipparchus

Figure 16. Hipparchus (highlighted), Jerry Hubbell, Locust Grove, VA, USA, 13 March 2011, 02:17 UT, Colongi- tude 9.3°, 120 mm f/7.5 Refractor, ATIK 314e CCD camera, North/Up, East/Right.

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The Lunar 100: Feature 29-Ariadaeus Rille

Figure 17. Rima Ariadaeus, Jorge Arranz, Lunar Group of the Madrid Astronomical Association (AAM), Madrid, Spain, 30 May 2020, 21:10 UT, Colongitude 14.5°, 250 mm f/5 Dobsonian, 8mm eyepiece + 2x Barlow 312x, Seeing 6/10, Graphite bars and pencil on white paper, North/Left, East/Up.

Jorge relates the following about his sketch:

“The drawing was intended to render the Cayley Plains (L50) and part of the Imbrium Sculpture over Julius Caesar (L63), but some trees in the way had it abruptly finished. So they are just out- lined. Please realize that it was done from an urban front yard and with a street-lamp over the telescope!”

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The Lunar 100: Feature 30-Schiller

Figure 18. Schiller, LTVT Aerial View, Jerry Hubbell, Locust Grove, VA USA, 03 February 2012, 23:36 UT, Colon- gitude 4.7.5°, 10-inch (254 mm) f/10 Meade SCT, TIS DMK21AU04.AS CCD camera, Seeing 8/10, Transparency 3/5, North/Up, East/Right.

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The Lunar 100: Feature 30-Schiller

Figure 19. Schiller, Jorge Arranz, Lunar Group of the Madrid Astronomical Association (AAM), Madrid, Spain, 02 June 2020, 23:00 UT, Colongitude 51.8°, 250 mm f/5 Dobsonian, 8mm eyepiece + 2x Barlow 312x, Seeing 5/10, Graphite bars and pencil on white paper, North/Down, East/Left.

As always, we had a good response to our request for images and drawings for the third set of 10 features of the Lunar 100 (L21 – L30). I am grateful for all the submissions we received. We had a total of 71 images and drawings submitted to the TLO from over 15 astronomers. Most of the images came from Alberto Anunziato’s groups, SAO-SLA, and LIADA. Previously 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 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.”

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We look forward to future drawings and images submitted by ALPO, SLA, SAO, LIADA members and others from all across the world. Please share with us any images you have in your image cata- log, 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., 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)

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).

The Lunar Observer/September 2020/ 46

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

The Lunar Observer/September 2020/ 47

Recent Topographic Studies Additional images of Lunar 21 Fracastorius

Fracastorius, Fabio Verza, SNdR Luna UAI-Italy, Milan, Italy. 23 August 2020 18:37 UT. Celestron 4 inch Maksutov- Cassegrain telescope, fl 1325 mm, As- tronomik IR Pro 807 filter, ZWO ASI 290 MM camera.

Online readers, click on images for hyperlinks

Fracastorius, Leandro Sid, AEA - Oro Verde, Entre Rios, Argentina. 23 August 2020 22:28 UT. Meade StarNavigator NG Maksutov-Cassegrain telescope, 90 mm, 1,250 mm fl, Samsung J7 Prime camera.

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Recent Topographic Studies Additional images of Lunar 21 Fracastorius

Fracastorius, Fabio Verza, SNdR Lu- na UAI-Italy, Milan, Italy. 07 August 2020 02:11 UT. Celestron CPC800 8 inch Schmidt-Cassegrain telescope, Barlow 1.3 x, Astronomik IR Pro 807 filter, ZWO ASI 290 MM camera.

Fracastorius, Francisco Alsina Cardinalli, SLA-LIADA, Oro Verde, Argentina. 14 January 2016 23:20 UT. Meade LX 200 10 inch Schmidt-Cassegrain telescope, Canon EOS Digital Rebel XS camera.

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Recent Topographic Studies Additional images of Lunar 21 Fracastorius

Fracastorius, Pedro Romano, SLA-LIADA, San Juan, Argentina. 19 June 2018 23:20 UT. 500 mm reflector telescope, ZWO SI 120 camera.

Below, Fracastorius, Sergio Babino, SAO-LIADA, Montevideo, Uruguay. 14 March 2020 01:59 UT. 203 mm catadrioptic telescope, ZWO ASI 174 camera.

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