Lunar 100

Objects in the Lunar 100 are arranged from the easiest to view to the most difficult. This is more systematic than the haphazard approach that produced the Messier list. Indeed, just by knowing a feature's Lunar 100 number, you have some idea of how easy or challenging it will be to see. For example, the Moon itself is L1, while L2 is earthshine and L3 is the light/dark dichotomy between lunar highlands and maria ("seas"). I'd be surprised if anyone reading this couldn't tick those off the list right now. Higher-numbered objects are smaller, less conspicuous, or positioned closer to the limb, making them more challenging to locate and view. I was going to wait until the list was more complete before posting. My aim of course is to complete the list and image all 100. I could cheat by just posting a pic of the full moon and complete 99%. But where is the fun in that.. .  I hope you enjoy my list L Image List Feature Name Significance Lat. Long. Diam.(km) Rükl Chart (°) (°) 1    Moon Large satellite — — 3,476 — 2 Earthshine Twice reflected sunlight — — — — 3 Mare/highland dichotomy Two materials with distinct compositions — — — — 4 Apennines Imbrium basin rim 18.9N 3.7W 70 22 5   Copernicus Archetypal large complex crater 9.7N 20.1W 93 31 6 Tycho Large rayed crater with impact melts 43.4S 11.1W 85 64 7 Altai Scarp Nectaris basin rim 24.3S 22.6E 425 57 8 Theophilus, Cyrillus, Catharina Crater sequence illustrating stages of degradation 13.2S 24.0E — 46, 57 9 Clavius Lacks basin features in spite of its size 58.8S 14.1W 225 72 10 Mare Crisium Mare contained in large circular basin 18.0N 59.0E 540 26, 27, 37, 38 11 Aristarchus Very bright crater with dark bands on its walls 23.7N 47.4W 40 18 12 Proclus Oblique-impact rays 16.1N 46.8E 28 26 13 Gassendi Floor-fractured crater 17.6S 40.1W 101 52 14 Sinus Iridum Very large crater with missing rim 45.0N 32.0W 260 10 15 Straight Wall Best example of a lunar fault 21.8S 7.8W 110 54 16 Petavius Crater with domed & fractured floor 25.1S 60.4E 177 59 17    Schröter's Valley Giant sinuous rille 26.2N 50.8W 168 18 18 Mare Serenitatis dark edges Distinct mare areas with different compositions 17.8N 23.0E N/A 24 19 Alpine Valley Lunar graben 49.0N 3.0E 165 4 20 Posidonius Floor-fractured crater 31.8N 29.9E 95 14
21 Fracastorius Crater with subsided & fractured floor 21.5S 33.2E 124 58 22 Aristarchus Plateau Mysterious uplifted region mantled with pyroclastics 26.0N 51.0W 150 18 23 Pico Isolated Imbrium basin-ring fragment 45.7N 8.9W 25 11 24 Hyginus Rille Rille containing rimless collapse pits 7.4N 7.8E 220 34 25 Messier & Messier A Oblique ricochet-impact pair 1.9S 47.6E 11 48 26 Mare Frigoris Arcuate mare of uncertain origin 56.0N 1.4E 1600 2–6 27 Archimedes Large crater lacking central peak 29.7N 4.0W 83 12, 22 28 Hipparchus First drawing of a single crater 5.5S 4.8E 150 44, 45 29 Aridaeus Rille Long, linear graben 6.4N 14.0E 250 34 30 Schiller Possible oblique impact 51.9S 39.0W 180 71 31 Taruntius Young floor-fractured crater 5.6N 46.5E 56 37 32 Arago Alpha & Beta Volcanic domes 6.2N 21.4E 26 35 33 Serpentine Ridge Basin inner-ring segment 27.3N 25.3E 155 24 34 Lacus Mortis Strange crater with rille & ridge 45.0N 27.2E 152 14 35 Triesnecker Rilles Rille family 4.3N 4.6E 215 33 36 Grimaldi basin A small two-ring basin 5.5S 68.3W 440 39 37 Bailly Barely discernible basin 66.5S 69.1W 303 71 38 Sabine & Ritter Possible twin impacts 1.7N 19.7E 30 35 39 Schickard Crater floor with Orientale basin ejecta stripe 44.3S 55.3W 227 62 40 Janssen Rille Rare example of a highland rille 45.4S 39.3E 190 67, 68
41 Bessel ray Ray of uncertain origin near Bessel 21.8N 17.9E N/A 24 42 Marius Hills Complex of volcanic domes & hills 12.5N 54.0W 125 28, 29 43 Wargentin A crater filled to the rim with lava or ejecta 49.6S 60.2W 84 70 44 Mersenius Domed floor cut by secondary craters 21.5S 49.2W 84 51 45 Maurolycus Region of saturation cratering 42.0S 14.0E 114 66 46 Regiomontanus central peak Possible volcanic peak 28.0S 0.6W 124 55 47 Alphonsus dark spots Dark-halo eruptions on crater floor 13.7S 3.2W 119 44 48 Cauchy region Fault, rilles, & domes 10.5N 38.0E 130 36 49 Gruithuisen Delta & Gamma Volcanic domes formed with viscous lavas 36.3N 40.0W 20 9 50 Cayley Plains Light, smooth plains of uncertain origin 4.0N 15.1E 14 34 51 Davy crater chain Result of comet-fragment impacts 11.1S 6.6W 50 43 52 Crüger Possible volcanic caldera 16.7S 66.8W 45 50 53 Lamont Possible buried basin 4.4N 23.7E 106 35 54 Hippalus Rilles Rilles concentric to Humorum basin 24.5S 29.0W 240 52, 53 55 Baco Unusually smooth crater floor & surrounding plains 51.0S 19.1E 69 74 56 Australe basin A partially flooded ancient basin 49.8S 84.5E 880 76 57 Reiner Gamma Conspicuous swirl & magnetic anomaly 7.7N 59.2W 70 28 58 Rheita Valley Basin secondary-crater chain 42.5S 51.5E 445 68 59 Schiller-Zucchius basin Badly degraded overlooked basin 56.0S 45.0W 335 70, 71 60 Kies Pi Volcanic dome 26.9S 24.2W 45 53 61 Mösting A Simple crater close to center of lunar near side 3.2S 5.2W 13 43 62 Rümker Large volcanic dome 40.8N 58.1W 70 8 63 Imbrium sculpture Basin ejecta near & overlying Boscovich & Julius Caesar 11.0N 12.0E — 34 64 Descartes Apollo 16 landing site; putative region of highland volcanism 11.7S 15.7E 48 45 65 Hortensius domes Dome field north of Hortensius 7.6N 27.9W 10 30 66 Hadley Rille Lava channel near Apollo 15 landing site 25.0N 3.0E — 22 67 Fra Mauro formation Apollo 14 landing site on Imbrium ejecta 3.6S 17.5W — 42 68 Flamsteed P Proposed young volcanic crater & Surveyor 1 landing site 3.0S 44.0W 112 40 69 Copernicus secondary craters Rays & craterlets near Pytheas 19.6N 19.1W 4 20 70 Humboldtianum basin Multi-ring impact basin 57.0N 80.0E 650 7 71 Sulpicius Gallus dark mantle Ash eruptions northwest of crater 19.6N 11.6E 12 23 72 Atlas dark-halo craters Explosive volcanic pits on the floor of Atlas 46.7N 44.4E 87 15 73 Smythii basin Difficult-to-observe basin scarp & mare 2.0S 87.0E 740 38, 49 74 Copernicus H Dark-halo impact crater 6.9N 18.3W 5 31 75 Ptolemaeus B Saucerlike depression on the floor of Ptolemaeus 8.0S 0.8W 16 44 76 W. Bond Large crater degraded by Imbrium ejecta 65.3N 3.7E 158 4 77 Sirsalis Rille Procellarum basin radial rilles 15.7S 61.7W 425 39, 50 78 Lambert R A buried "ghost" crater 23.8N 20.6W 54 20 79 Sinus Aestuum Eastern dark-mantle volcanic deposit 12.0N 3.5W 90 33 80 Orientale basin Youngest large impact basin 19.0S 95.0W 930 50
81 Hesiodus A Concentric crater 30.1S 17.0W 15 54 82 Linné Small crater once thought to have disappeared 27.7N 11.8E 2.4 23 83 Plato craterlets Crater pits at limits of detection 51.6N 9.4W 101 3, 4 84 Pitatus Crater with concentric rilles 29.8S 13.5W 97 54 85 Langrenus rays Aged ray system 8.9S 60.9E 132 49 86 Prinz Rilles Rille system near the crater Prinz 27.0N 43.0W 46 19 87 Humboldt Crater with central peaks & dark spots 27.0S 80.9E 207 60 88 Peary Difficult-to-observe polar crater 88.6N 33.0E 74 4, II 89 Valentine Dome Volcanic dome 30.5N 10.1E 30 13 90 Armstrong, Aldrin & Collins Small craters near the Apollo 11 landing site 1.3N 23.7E 3 35 91 De Gasparis Rilles Area with many rilles 25.9S 50.7W 30 51 92 Gylden Valley Part of the Imbrium radial sculpture 5.1S 0.7E 47 44 93 Dionysius rays Unusual & rare dark rays 2.8N 17.3E 18 35 94 Drygalski Large south-pole region crater 79.3S 84.9W 162 72, VI 95 Procellarum basin The Moon's biggest basin? 23.0N 15.0W 3200 — 96 Leibnitz Mountains Rim of South Pole-Aitken basin 85.0S 30.0E — 73, V 97 Inghirami Valley Orientale basin ejecta 44.0S 73.0W 140 61 98 Imbrium lava flows Mare lava-flow boundaries 32.8N 22.0W — 10 99 Ina D-shaped young volcanic caldera 18.6N 5.3E 3 22 100 Mare Marginis swirls Possible magnetic field deposits 18.5N 88.0E — 27, III
Also included here is the handy observing / Imaging guide for day by day. Day 2 2 Earthshine 10 Mare Crisium 16 Petavius 56 Mare Australe 70 Humboltianum Basin (Mare Humboltianum) 73 Mare Smythii 85 Langrenus rays 87 Humboldt 100 Mare Marginis swirls Day 3 58 Rheita Valley (Vallis Rheita) Day 4 12 Proclus 25 Messier & Messier A 31 Taruntius 40 Janssen Rille (Rima Janssen) 48 Cauchy region 72 Atlas dark halo craters Day 5 7 Altai Scarp (Rupes Altai) 8 Theophilus, Cyrillus, Catherina 18 Mare Serenitatus dark edges 20 Posidonius 21 Fracastorius 26 Mare Frigoris 32 Arago Alpha & Beta 33 Serpentine Ridge (Dorsa Smirnov) 34 Lacus Mortis 38 Ritter & Sabine 53 Lamont 55 Baco 90 Armstrong, Aldrin, Collins Day 6 24 Hyginus Rille (Rima Hyginus) 28 Hipparchus 29 Ariadaeus Rille (Rima Ariadaeus) 35 Triesnecker Rille (Rimae Triesnecker) 41 Bessel ray 45 Maurolycus 50 Cayley Plains 63 Imbrium sculpture 64 Descarte 71 Sulpicus Gallus 82 Linne 89 Valentine dome 93 Dionysius rays Day 7 4 Apennines (Montes Apenninus) 19 Alpine Valley (Vallis Alpes) 27 Archimedes 46 Regiomontanus central peak 66 Hadley Rille (Rima Hadley) 75 Ptolemaeus B 76 W. Bond 88 Peary 92 Gylden Valley Day 8 15 Straight Wall (Rupes Recta) 47 Alphonsus 51 Davy crater chain 61 Mosting A 79 Sinus Aestuum 83 Plato craterlets 96 Leibnitz Mountains 99 Ina caldera Day 9 5 Copernicus 6 Tycho 9 Clavius 14 Sinus Iridum 60 Kies Pi 65 Hortensius dome 67 Fra Mauro formation 69 Copernicus secondary craters 74 Copernicus H 78 Lambert R 81 Hesiodus A 84 Pitatus 94 Drygalski Day 10 13 Gassendi 30 Schiller 49 Griuthuisen Delta & Gamma 54 Hippalus Rilles (Rimae Hippalus) 59 Schiller-Zucchius basin 68 Flamsteed P 98 Imbrium lava flows Day 11 11 Aristarchus 17 Schroter’s Valley 22 Aristarchus Plateau 39 Schickard 42 Marius Hills 44 Mersenius 57 Reiner Gamma 86 Prinz Rilles (Rimae Prinz) 91 De Gasparis Rilles (Rimae De Gasparis) Day 12 37 Bailly 43 Wargentin 62 Rumker Hills (Mons Rumker) 77 Sirsalis Rille (Rima Sirsalis) Day 13 36 Grimaldi basin 52 Cruger 80 Orientale Basin (Mare Orientale) 97 Inghirami Valley (Vallis Inghirami) Day 14 1 Moon 3 Mare/highland dichotomy 95 Procellarum Basin Days 15-16-17 10 Mare Crisium 12 Proclus 16 Petavius 25 Messier & Messier A 31 Taruntius 40 Janssen Rille (Rima Janssen) 56 Mare Australe 58 Rheita Valley (Vallis Rheita) 70 Humboldtianum basin 72 Atlas dark-halo crater 73 Smythii basin (Mare Smythii) 85 Langrenus rays 87 Humbolt 100 Mare Marginis swirls Days 18-19-20 7 Altai Scarp (Rupes Altai) 8 Theophilus, Cyrillus, & Catharina 18 Mare Serenitatus dark edges 20 Posidonius 21 Fracastorius 29 Ariadeus Rille (Rima Ariadeus) 32 Arago Alpha & Beta 33 Serpentine Ridge (Dorsa Smirnov) 34 Lacus Mortis 38 Sabine & Ritter 41 Bessel ray 45 Maurolycus 48 Cauchy region 50 Cayley plains 53 Lamont 55 Baco 63 Imbrium sculpture 64 Descarte 71 Sulpicius Gallus dark mantle 82 Linne 89 Valentine dome 90 Armstrong, Aldrin, Collins 93 Dionysius rays Days 21-22 4 Apennines (Montes Apenninus) 5 Copernicus 6 Tycho 9 Clavius 15 Straight Wall (Rupes Recta) 19 Alpine Valley (Vallis Alpes) 23 Pico 24 Hyginus Rille (Rima Hyginus) 26 Mare Frigoris 27 Archimedes 28 Hipparchus 35 Triesnecker Rilles (Rimae Triesnecker) 46 Regiomontanus central peak 47 Alphonsus dark spots 51 Davy crater chain 61 Mosting A 66 Hadley Rille (Rima Hadley) 67 Fra Mauro formation 69 Copernicus secondary crater 74 Copernicus H 75 Ptolemaeus B 76 W. Bond 78 Lambert R 79 Sinus Aestuum 81 Hesiodus A 83 Plato craterlets 84 Pitatus 88 Peary 92 Gylden Valley 94 Drygalski 96 Leibnitz Mountains 99 Ina Caldera Days 23-24-25 13 Gassendi 14 Sinus Iridum 30 Schiller 49 Gruithuisen Delta & Gamma 54 Hippalus Rille (Rima Hippalus) 59 Schiller-Zucchias basin 60 Kies Pi 65 Hortensius domes 68 Flammsteed P 98 Imbrium lava flows Days 26-27-28 11 Aristarchus 17 Schroter’s Valley 22 Aristarchus Plateau 36 Grimaldi 37 Bailly 39 Schickard 42 Marius Hills 43 Wargentin 44 Mersenius 52 Cruger 57 Reiner Gamma 62 Rumker Hills (Mons Rumker) 77 Sirsalis Rille (Rima Sirsalis) 80 Orientale basin 86 Prinz Rilles (Rimae Prinz) 91 De Gasparis Rilles (Rimae De Gasparis) 97 Inghirami Valley (Vallis Inghirami)