The Moon is around for a good portion of every month so why not make the most of it. The Lunar 100 is to the Moon what the Messier catalogue is to deep sky objects.
I always find it useful to set myself little projects in order to focus (pun intended) my observing or imaging, otherwise I go outside and think “what shall I do now”. On my own website I set myself projects and targets, the Lunar 100 being one of them.
The Lunar 100 was created by Planetary Scientist Charles A. Wood in the April 2004 edition of Sky and Telescope. It is a list of the most interesting Lunar features, arranged in order of difficulty, with L1 being the easiest (the Moon!) to L100 (Mare Marginis, only visible when libration allows). It contains interesting regions, craters, basins, mountains, rilles and domes that typify Lunar morphology.
Examples include:
- L5 Copernicus – Archetypal large complex crater
- L15 Straight Wall – Best example of a lunar fault
- L27 Archimedes – Large crater lacking central peak
- L66 Hadley Rille – Lava channel near Apollo 15 landing site
- …see below for a full list
However you do it – observing, drawing or imaging, keep a record of what you do, even if it is only a tick list, so you can look back on it and return to some of the more interesting features again. Many features can be observed using small telescopes. Some of the later ones may require a larger (6 inch plus) instrument.
If you manage to image or observe any of the Lunar 100, why not post your images and observations to our Flickr group, Facebook page or Twitter feed.
Here is a list from Wikipedia, with links to individual items, of the Lunar 100. To find the objects, use a Moon atlas such as the excellent and free Virtual Moon Atlas Pro.
L | Feature Name | Significance | Lat. (°) | Long. (°) | Diam. (km) |
L1 | Moon | Large satellite | — | — | 3.476 |
L2 | Earthshine | Twice reflected sunlight | — | — | |
L3 | Mare/highland dichotomy | Two materials with distinct compositions | — | — | |
L4 | Apennines | Imbrium basin rim | 18.9N | 3.7W | 70 |
L5 | Copernicus | Archetypal large complex crater | 9.7N | 20.1W | 93 |
L6 | Tycho | Large rayed crater with impact melts | 43.4S | 11.1W | 85 |
L7 | Altai Scarp | Nectaris basin rim | 24.3S | 22.6E | 425 |
L8 | Theophilus, Cyrillus, Catharina | Crater sequence illustrating stages of degradation | 13.2S | 24.0E | — |
L9 | Clavius | Lacks basin features in spite of its size | 58.8S | 14.1W | 225 |
L10 | Mare Crisium | Mare contained in large circular basin | 18.0N | 59.0E | 540 |
L11 | Aristarchus | Very bright crater with dark bands on its walls | 23.7N | 47.4W | 40 |
L12 | Proclus | Oblique-impact rays | 16.1N | 46.8E | 28 |
L13 | Gassendi | Floor-fractured crater | 17.6S | 40.1W | 101 |
L14 | Sinus Iridum | Very large crater with missing rim | 45.0N | 32.0W | 260 |
L15 | Straight Wall | Best example of a lunar fault | 21.8S | 7.8W | 110 |
L16 | Petavius | Crater with domed and fractured floor | 25.1S | 60.4E | 177 |
L17 | Schröter’s Valley | Giant sinuous rille | 26.2N | 50.8W | 168 |
L18 | Mare Serenitatis dark edges | Distinct mare areas with different compositions | 17.8N | 23.0E | N/A |
L19 | Alpine Valley | Lunar graben | 49.0N | 3.0E | 165 |
L20 | Posidonius | Floor-fractured crater | 31.8N | 29.9E | 95 |
L21 | Fracastorius | Crater with subsided and fractured floor | 21.5S | 33.2E | 124 |
L22 | Aristarchus Plateau | Mysterious uplifted region mantled with pyroclastics | 26.0N | 51.0W | 150 |
L23 | Pico | Isolated Imbrium basin-ring fragment | 45.7N | 8.9W | 25 |
L24 | Hyginus Rille | Rille containing rimless collapse pits | 7.4N | 7.8E | 220 |
L25 | Messier & Messier A | Oblique ricochet-impact pair | 1.9S | 47.6E | 11 |
L26 | Mare Frigoris | Arcuate mare of uncertain origin | 56.0N | 1.4E | 1600 |
L27 | Archimedes | Large crater lacking central peak | 29.7N | 4.0W | 83 |
L28 | Hipparchus | First drawing of a single crater | 5.5S | 4.8E | 150 |
L29 | Ariadaeus Rille | Long, linear graben | 6.4N | 14.0E | 250 |
L30 | Schiller | Possible oblique impact | 51.9S | 39.0W | 180 |
L31 | Taruntius | Young floor-fractured crater | 5.6N | 46.5E | 56 |
L32 | Arago Alpha & Beta | Volcanic domes | 6.2N | 21.4E | 26 |
L33 | Serpentine Ridge | Basin inner-ring segment | 27.3N | 25.3E | 155 |
L34 | Lacus Mortis | Strange crater with rille and ridge | 45.0N | 27.2E | 152 |
L35 | Triesnecker Rilles | Rille family | 4.3N | 4.6E | 215 |
L36 | Grimaldi basin | A small two-ring basin | 5.5S | 68.3W | 440 |
L37 | Bailly | Barely discernible basin | 66.5S | 69.1W | 303 |
L38 | Sabine and Ritter | Possible twin impacts | 1.7N | 19.7E | 30 |
L39 | Schickard | Crater floor with Orientale basin ejecta stripe | 44.3S | 55.3W | 227 |
L40 | Janssen Rille | Rare example of a highland rille | 45.4S | 39.3E | 190 |
L41 | Bessel ray | Ray of uncertain origin near Bessel | 21.8N | 17.9E | N/A |
L42 | Marius Hills | Complex of volcanic domes & hills | 12.5N | 54.0W | 125 |
L43 | Wargentin | A crater filled to the rim with lava or ejecta | 49.6S | 60.2W | 84 |
L44 | Mersenius | Domed floor cut by secondary craters | 21.5S | 49.2W | 84 |
L45 | Maurolycus | Region of saturation cratering | 42.0S | 14.0E | 114 |
L46 | Regiomontanus central peak | Possible volcanic peak | 28.0S | 0.6W | 124 |
L47 | Alphonsus dark spots | Dark-halo eruptions on crater floor | 13.7S | 3.2W | 119 |
L48 | Cauchy region | Fault, rilles and domes | 10.5N | 38.0E | 130 |
L49 | Gruithuisen Delta and Gamma | Volcanic domes formed with viscous lavas | 36.3N | 40.0W | 20 |
L50 | Cayley Plains | Light, smooth plains of uncertain origin | 4.0N | 15.1E | 14 |
L51 | Davy crater chain | Result of comet-fragment impacts | 11.1S | 6.6W | 50 |
L52 | Crüger | Possible volcanic caldera | 16.7S | 66.8W | 45 |
L53 | Lamont | Possible buried basin | 4.4N | 23.7E | 106 |
L54 | Hippalus Rilles | Rilles concentric to Humorum basin | 24.5S | 29.0W | 240 |
L55 | Baco | Unusually smooth crater floor and surrounding plains | 51.0S | 19.1E | 69 |
L56 | Australe basin | A partially flooded ancient basin | 49.8S | 84.5E | 880 |
L57 | Reiner Gamma | Conspicuous swirl and magnetic anomaly | 7.7N | 59.2W | 70 |
L58 | Rheita Valley | Basin secondary-crater chain | 42.5S | 51.5E | 445 |
L59 | Schiller–Zucchius basin | Badly degraded overlooked basin | 56.0S | 45.0W | 335 |
L60 | Kies Pi | Volcanic dome | 26.9S | 24.2W | 45 |
L61 | Mösting A | Simple crater close to center of lunar near side | 3.2S | 5.2W | 13 |
L62 | Rümker | Large volcanic dome | 40.8N | 58.1W | 70 |
L63 | Imbrium sculpture | Basin ejecta near and overlying Boscovich and Julius Caesar | 11.0N | 12.0E | — |
L64 | Descartes | Apollo 16 landing site; putative region of highland volcanism | 11.7S | 15.7E | 48 |
L65 | Hortensius domes | Dome field north of Hortensius | 7.6N | 27.9W | 10 |
L66 | Hadley Rille | Lava channel near Apollo 15 landing site | 25.0N | 3.0E | — |
L67 | Fra Mauro formation | Apollo 14 landing site on Imbrium ejecta | 3.6S | 17.5W | — |
L68 | Flamsteed P | Proposed young volcanic crater and Surveyor 1 landing site | 3.0S | 44.0W | 112 |
L69 | Copernicus secondary craters | Rays and craterlets near Pytheas | 19.6N | 19.1W | 4 |
L70 | Humboldtianum basin | Multi-ring impact basin | 57.0N | 80.0E | 650 |
L71 | Sulpicius Gallus dark mantle | Ash eruptions northwest of crater | 19.6N | 11.6E | 12 |
L72 | Atlas dark-halo craters | Explosive volcanic pits on the floor of Atlas | 46.7N | 44.4E | 87 |
L73 | Smythii basin | Difficult-to-observe basin scarp and mare | 2.0S | 87.0E | 740 |
L74 | Copernicus H | Dark-halo impact crater | 6.9N | 18.3W | 5 |
L75 | Ptolemaeus B | Saucer-like depression on the floor of Ptolemaeus | 8.0S | 0.8W | 16 |
L76 | W. Bond | Large crater degraded by Imbrium ejecta | 65.3N | 3.7E | 158 |
L77 | Sirsalis Rille | Procellarum basin radial rilles | 15.7S | 61.7W | 425 |
L78 | Lambert R | A buried “ghost” crater | 23.8N | 20.6W | 54 |
L79 | Sinus Aestuum | Eastern dark-mantle volcanic deposit | 12.0N | 3.5W | 90 |
L80 | Orientale basin | Youngest large impact basin | 19.0S | 95.0W | 930 |
L81 | Hesiodus A | Concentric crater | 30.1S | 17.0W | 15 |
L82 | Linné | Small crater once thought to have disappeared | 27.7N | 11.8E | 2.4 |
L83 | Plato craterlets | Crater pits at limits of detection | 51.6N | 9.4W | 101 |
L84 | Pitatus | Crater with concentric rilles | 29.8S | 13.5W | 97 |
L85 | Langrenus rays | Aged ray system | 8.9S | 60.9E | 132 |
L86 | Prinz Rilles | Rille system near the crater Prinz | 27.0N | 43.0W | 46 |
L87 | Humboldt | Crater with central peaks and dark spots | 27.0S | 80.9E | 207 |
L88 | Peary | Difficult-to-observe polar crater | 88.6N | 33.0E | 74 |
L89 | Valentine Dome | Volcanic dome | 30.5N | 10.1E | 30 |
L90 | Armstrong, Aldrin and Collins | Small craters near the Apollo 11 landing site | 1.3N | 23.7E | 3 |
L91 | De Gasparis Rilles | Area with many rilles | 25.9S | 50.7W | 30 |
L92 | Gyldén Valley | Part of the Imbrium radial sculpture | 5.1S | 0.7E | 47 |
L93 | Dionysius rays | Unusual and rare dark rays | 2.8N | 17.3E | 18 |
L94 | Drygalski | Large south-pole region crater | 79.3S | 84.9W | 162 |
L95 | Procellarum basin | The Moon’s biggest basin? | 23.0N | 15.0W | 3200 |
L96 | Leibnitz Mountains | Rim of South Pole-Aitken basin | 85.0S | 30.0E | — |
L97 | Inghirami Valley | Orientale basin ejecta | 44.0S | 73.0W | 140 |
L98 | Imbrium lava flows | Mare lava-flow boundaries | 32.8N | 22.0W | — |
L99 | Ina | D-shaped young volcanic caldera | 18.6N | 5.3E | 3 |
L100 | Mare Marginis swirls | Possible magnetic field deposits | 18.5N | 88.0E | — |
Mark Phillips