# Lunar 100

The Lunar 100 (L100) is a list of one hundred of the most interesting features to observe on the Moon. The list was first described by Charles A. Wood in the article The Lunar 100 in Sky & Telescope magazine, April 2004.
With this selection, Wood tried to give astronomy fans a list similar to the Messier catalog of deep-sky objects, but of a more familiar object, the Moon. The objects listed include craters, seas, mountains and other features, and are arranged in ascending order of observational difficulty. The Moon is L1, L2 is Earthshine, L3 is the contrast between the dark seas and the lighter highlands. Starting from L4 we have geological features, such as craters (Tycho, L6), valleys (Vallis Schröteri, L17) and mountains (Leibnitz Mountains, L96). The last entry is L100, the magnetic swirls of Marginis Sea.

## Lunar 100 - list

| 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 | — |