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 Feature of the Month—September 2019 Gemma Frisius Sketch by Robert H. Hayes, Jr—Worth, Illinois, USA June 11, 2019 0226-0306; 0328-0340 UT, 15 cm reflector, 170 x Seeing 8-9/10, transparency 6/6 I observed this crater and vicinity on the evening of June 10/11, 2019. This area is located north of Maurolycus and just west of Gemma Frisius itself. Gemma Frisius D (Gem Fri D) is another example of a non-circular crater. Its eastern side is quite round, but its western side has sharp angles. There are straight edges coming to a point on the west end. Its interior shadow also looked odd. The shape may have resulted from slumped walls. Gem Fri D has obliterated the north end of a larger but vague old ring. There is a great variety of craters nearby. Gemma Frisius F is the middling crater just southwest of the old ring. A clump of four smaller craters straddles this old rim. Three more small pits and a fuzzy squarish crater are east of this group. Gemma Frisius Z is the largest crisp feature southwest of D. The Lunar Quad- rant map shows it as single, but I saw it as a double crater. A vague saucer is just east of Z, and a larger, similar saucer is to its north. There is a generous sprinkling of tiny pits in this area. A line of three more small craters extends northward from Gem Fri D. These are near a low curved ridge which may be part of the ghost ring Gemma Frisius G. The large, deep crater southwest of Gem Fri F is Kaiser C, and a low squarish ring is just to its west. Gemma Frisius EA is well to the southeast of Gem Fri D, and is very much like Gem Fri F. A small, shallow crater is just east of Gem Fri EA, and two fuzzy craters are to its west, toward Kaiser C. Two small, crisper pits are to their north. Short ridges extend from some craters, notably Kaiser C and Gem Fri Z. A strip slightly brighter than the surrounding area takes in Gem Fri F and Kaiser C. The Lunar Observer/September 2019/ 1 Lunar Calendar September 2019 2019 U.T. EVENT September 06 03:10 First Quarter 08 Greatest Southern declination, -22.5o 13 1400 Moon Apogee, 406,377 km, diameter 29’ 24” 14 0433 Full Moon 22 0241 Last Quarter 22 0900 Moon 2.0o south of M35 23 Greatest North declination +22.7o 24 2200 Moon 0.4oN of M44 28 0200 Moon Perigee, 357,803 km, diameter 33’ 24” Large Tides 28 1826 New Moon, Lunation 1197 Favorable Librations September 7 Hecataeus B Crater September 10 Hubble Crater September 26 Baade Crater September 27 Hausen Crater 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 pages 20-21 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 availa- ble 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 Journal 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 draw- ings and images produced by individual 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 2019/ 2 LUNAR TOPOGRAPHICAL 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 Alberto Anunziato - Oro Verde, Argentina. Digital image and article about Alphonsus. Fransico Alsina Cardinali - Oro Verde, Argentina. Digital images of Burg and Theophilus. Jairo Chavez - Popayán, Columbia. Digital images of Copernicus (2), Full Moon (2), Plato, Tycho (2), Clavius, Werner, Waxing Gibbous Moon and Waning Gibbous Moon. Darryl Wilson- Marshall, Virginia, USA. Digital thermal and comparison images of the Moon (6), article about lunar thermal imaging. Walter Ricardo Elias -AEA - Oro Verde, Entre Rios, Argentina. Digital images of Prolus (6), Tycho, Plato (3), Macrobius, Mare Tranquillitatis, maxing crescent Moon, Copernicus, Conon, Manilius (2). Howard Eskildsen - Ocala, Florida, USA. Digital image and article about Herodotus Omega Dome, digital image and article about Rimae Ritter and Ritter 1 Dome, images of the Men- alaus domes, Murchison domes, Aristillus to Putridinus and lunar domes near Aristillus. Desiré Godoy —Oro Verde, Argentina. Digital image of Aristarchus. Robert Hays Jr. -Worth, Illinois, USA. Drawing of Gemma Frisius Richard Hill – Tucson Arizona, USA. Digital images and article about Taurus Littrow, Mare Smythii, and North of Aristarchus. Digital images of Alphonsus (11), Aristarchus (12), Catena Davy. Jerry Hubbell - Wilderness, Virginia, USA. Digital image of the 21 day old Moon, Focus On article Alphonsus and Arsistarchus.. David Teske—Louisville, Mississippi, USA. Digital image and article about Grimaldi, digital image of Aristarchus.. Alan Trumper– AEA - Oro Verde, Entre Rios, Argentina Digital images of Censorinus and Mare Nectaris. Román García Verdier -Paraná, Argentina. Digital image of Aristarchus. Many thanks for all these observations, images, and drawings. The Lunar Observer/September 2019/ 3 Focus On: Alphonsus, Aristarchus & Herodotus Jerry Hubbell Assistant Coordinator, Lunar Topographical Studies This month we start on a new series of articles based on the craters in the Lunar Topographical Studies Selected Areas Program (SAP). This is a visual observing program that most beginners can easily start out using a small refractor or Newtonian reflector. This observing program is designed to focus atten- tion on areas of the moon that have shown unusual albedo changes during the lunation period. As stated on the main SAP webpage: “While there is a definite requirement to know how various lunar features change their normal appearance throughout a lunation in response to variations in phase angle, even more intriguing are those lunar features that behave in an unusual, sometimes unpre- dictable, and non-repeating manner as solar illumination changes. The A.L.P.O. Lunar Se- lected Areas Program (SAP) is chiefly concerned with systematically monitoring regular and cyclical long-term variations during many lunations of specifically designated, or “selected”, areas on the Moon. In general, the SAP is designed to intensively study and doc- ument for each of these features the normal albedo changes in response to conditions of varying solar illumination.” The SAP is a great way to get familiar with some of the main features of the Moon and enjoy visu- ally roaming over the landscape to see every tiny detail. You will find all the information needed to start this observing program at the link above. This series of articles over the next 6 months will cover the areas defined in the program and will be discussing an additional way you can observe and monitor these areas using your high-resolution lunar im- ages or other images you may find online. Using the Lunar Terminator Visualization Tool (LTVT) you can do various measurements of these craters and perhaps provide more insight into the “regular and cyclical long-term variations” that may occur in these areas. The LTVT allows you to not only measure the size of features, but also systematically measure the size of the various peaks and hills on the moon through shad- ow measurements. Some of the changes in these areas involve the shifting shadows and by measuring spe- cific locations over the long-term, the apparent shift in the measured heights over time might give us addi- tional data. Using the SAP crater drawing templates and the Lunar Aeronautical Charts for each crater, I will be identifying specific shadows to measure. I am welcome to any suggestions you may have in this regard. The craters in the SAP include: Alphonsus – 71 miles (118 km), Aristarchus – 24 miles (40 km), Atlas – 53 miles (88 km), Copernicus – 56 miles (93 km), Herodotus – 21 miles (35 km), Plato – 61 miles (101 km), Theophilus – 61 miles (101 km), and Tycho – 52 miles (86 km). This month we start with the craters Alphonsus, Aristarchus & Herodotus. Figures 1 and 3 show the crater drawing outlines used in the SAP for Alphonsus, Aristarchus & Herodotus, and Figures 2 and 4 show the Lunar Aeronautical Chart view of these craters.