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 groupFacebook 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.

LFeature NameSignificanceLat. (°)Long. (°)Diam. (km)
L1MoonLarge satellite3.476
L2EarthshineTwice reflected sunlight
L3Mare/highland dichotomyTwo materials with distinct compositions
L4ApenninesImbrium basin rim18.9N3.7W70
L5CopernicusArchetypal large complex crater9.7N20.1W93
L6TychoLarge rayed crater with impact melts43.4S11.1W85
L7Altai ScarpNectaris basin rim24.3S22.6E425
L8TheophilusCyrillusCatharinaCrater sequence illustrating stages of degradation13.2S24.0E
L9ClaviusLacks basin features in spite of its size58.8S14.1W225
L10Mare CrisiumMare contained in large circular basin18.0N59.0E540
L11AristarchusVery bright crater with dark bands on its walls23.7N47.4W40
L12ProclusOblique-impact rays16.1N46.8E28
L13GassendiFloor-fractured crater17.6S40.1W101
L14Sinus IridumVery large crater with missing rim45.0N32.0W260
L15Straight WallBest example of a lunar fault21.8S7.8W110
L16PetaviusCrater with domed and fractured floor25.1S60.4E177
L17Schröter’s ValleyGiant sinuous rille26.2N50.8W168
L18Mare Serenitatis dark edgesDistinct mare areas with different compositions17.8N23.0EN/A
L19Alpine ValleyLunar graben49.0N3.0E165
L20PosidoniusFloor-fractured crater31.8N29.9E95
L21FracastoriusCrater with subsided and fractured floor21.5S33.2E124
L22Aristarchus PlateauMysterious uplifted region mantled with pyroclastics26.0N51.0W150
L23PicoIsolated Imbrium basin-ring fragment45.7N8.9W25
L24Hyginus RilleRille containing rimless collapse pits7.4N7.8E220
L25Messier & Messier AOblique ricochet-impact pair1.9S47.6E11
L26Mare FrigorisArcuate mare of uncertain origin56.0N1.4E1600
L27ArchimedesLarge crater lacking central peak29.7N4.0W83
L28HipparchusFirst drawing of a single crater5.5S4.8E150
L29Ariadaeus RilleLong, linear graben6.4N14.0E250
L30SchillerPossible oblique impact51.9S39.0W180
L31TaruntiusYoung floor-fractured crater5.6N46.5E56
L32Arago Alpha & BetaVolcanic domes6.2N21.4E26
L33Serpentine RidgeBasin inner-ring segment27.3N25.3E155
L34Lacus MortisStrange crater with rille and ridge45.0N27.2E152
L35Triesnecker RillesRille family4.3N4.6E215
L36Grimaldi basinA small two-ring basin5.5S68.3W440
L37BaillyBarely discernible basin66.5S69.1W303
L38Sabine and RitterPossible twin impacts1.7N19.7E30
L39SchickardCrater floor with Orientale basin ejecta stripe44.3S55.3W227
L40Janssen RilleRare example of a highland rille45.4S39.3E190
L41Bessel rayRay of uncertain origin near Bessel21.8N17.9EN/A
L42Marius HillsComplex of volcanic domes & hills12.5N54.0W125
L43WargentinA crater filled to the rim with lava or ejecta49.6S60.2W84
L44MerseniusDomed floor cut by secondary craters21.5S49.2W84
L45MaurolycusRegion of saturation cratering42.0S14.0E114
L46Regiomontanus central peakPossible volcanic peak28.0S0.6W124
L47Alphonsus dark spotsDark-halo eruptions on crater floor13.7S3.2W119
L48Cauchy regionFault, rilles and domes10.5N38.0E130
L49Gruithuisen Delta and GammaVolcanic domes formed with viscous lavas36.3N40.0W20
L50Cayley PlainsLight, smooth plains of uncertain origin4.0N15.1E14
L51Davy crater chainResult of comet-fragment impacts11.1S6.6W50
L52CrügerPossible volcanic caldera16.7S66.8W45
L53LamontPossible buried basin4.4N23.7E106
L54Hippalus RillesRilles concentric to Humorum basin24.5S29.0W240
L55BacoUnusually smooth crater floor and surrounding plains51.0S19.1E69
L56Australe basinA partially flooded ancient basin49.8S84.5E880
L57Reiner GammaConspicuous swirl and magnetic anomaly7.7N59.2W70
L58Rheita ValleyBasin secondary-crater chain42.5S51.5E445
L59SchillerZucchius basinBadly degraded overlooked basin56.0S45.0W335
L60Kies PiVolcanic dome26.9S24.2W45
L61Mösting ASimple crater close to center of lunar near side3.2S5.2W13
L62RümkerLarge volcanic dome40.8N58.1W70
L63Imbrium sculptureBasin ejecta near and overlying Boscovich and Julius Caesar11.0N12.0E
L64DescartesApollo 16 landing site; putative region of highland volcanism11.7S15.7E48
L65Hortensius domesDome field north of Hortensius7.6N27.9W10
L66Hadley RilleLava channel near Apollo 15 landing site25.0N3.0E
L67Fra Mauro formationApollo 14 landing site on Imbrium ejecta3.6S17.5W
L68Flamsteed PProposed young volcanic crater and Surveyor 1 landing site3.0S44.0W112
L69Copernicus secondary cratersRays and craterlets near Pytheas19.6N19.1W4
L70Humboldtianum basinMulti-ring impact basin57.0N80.0E650
L71Sulpicius Gallus dark mantleAsh eruptions northwest of crater19.6N11.6E12
L72Atlas dark-halo cratersExplosive volcanic pits on the floor of Atlas46.7N44.4E87
L73Smythii basinDifficult-to-observe basin scarp and mare2.0S87.0E740
L74Copernicus HDark-halo impact crater6.9N18.3W5
L75Ptolemaeus BSaucer-like depression on the floor of Ptolemaeus8.0S0.8W16
L76W. BondLarge crater degraded by Imbrium ejecta65.3N3.7E158
L77Sirsalis RilleProcellarum basin radial rilles15.7S61.7W425
L78Lambert RA buried “ghost” crater23.8N20.6W54
L79Sinus AestuumEastern dark-mantle volcanic deposit12.0N3.5W90
L80Orientale basinYoungest large impact basin19.0S95.0W930
L81Hesiodus AConcentric crater30.1S17.0W15
L82LinnéSmall crater once thought to have disappeared27.7N11.8E2.4
L83Plato craterletsCrater pits at limits of detection51.6N9.4W101
L84PitatusCrater with concentric rilles29.8S13.5W97
L85Langrenus raysAged ray system8.9S60.9E132
L86Prinz RillesRille system near the crater Prinz27.0N43.0W46
L87HumboldtCrater with central peaks and dark spots27.0S80.9E207
L88PearyDifficult-to-observe polar crater88.6N33.0E74
L89Valentine DomeVolcanic dome30.5N10.1E30
L90ArmstrongAldrin and CollinsSmall craters near the Apollo 11 landing site1.3N23.7E3
L91De Gasparis RillesArea with many rilles25.9S50.7W30
L92Gyldén ValleyPart of the Imbrium radial sculpture5.1S0.7E47
L93Dionysius raysUnusual and rare dark rays2.8N17.3E18
L94DrygalskiLarge south-pole region crater79.3S84.9W162
L95Procellarum basinThe Moon’s biggest basin?23.0N15.0W3200
L96Leibnitz MountainsRim of South Pole-Aitken basin85.0S30.0E
L97Inghirami ValleyOrientale basin ejecta44.0S73.0W140
L98Imbrium lava flowsMare lava-flow boundaries32.8N22.0W
L99InaD-shaped young volcanic caldera18.6N5.3E3
L100Mare Marginis swirlsPossible magnetic field deposits18.5N88.0E

Mark Phillips