Updated:  1 May 2025
 


In 2016 a new section "Lunar Feature of the Month" was added to "The Sky Tonight" webpage.

The features chosen are craters, mountain ranges, peaks, volcanoes, rilles, grabens, fault scarps or other objects on the Moon, selected at random, which have unique or spectacular attributes.

Each object is illustrated with a recent photograph taken with Starfield Observatory's Alluna RC20 telescope, located in Queensland, Australia. If a better picture is obtained at a later date, it will replace or supplement the original one. The high-resolution bitmap images are compressed into jpeg format to make the files about one seventh as large, and therefore more suitable for webpage use.

As all large lunar features are named, the origin of the name will be given if it is important.

______________________________________

This page is an Archive of the Second Series of lunar features described from  # 101  in January 2025 to last month.  Earlier images in the First Series  ( # 1 - # 100  )  are available  here .

To help the lunar observer to find these features, each set of ten is preceded by an image of the Full Moon on which the locations of the ten photographs immediately following are shown according to their numbers in this series.
 


Finding your way around the Moon:            1  -   Seas and an Ocean


 

From north to south:


Latin Name
 

  English Equivalent

Mare Humboldtianum

Mare Frigoris

Mare Imbrium

Mare Serenitatis

Oceanus Procellarum

Mare Vaporum

Mare Crisium

Mare Marginis

Mare Insularum

Mare Tranquillitatis

Mare Smythii

Mare Fecunditatis

Mare Cognitum

Mare Nectaris

Mare Nubium

Mare Humorum

 

 Humboldt's Sea

Sea of Cold

Sea of Rains

Sea of Serenity

Ocean of Storms

Sea of Vapours

Sea of Crises

Sea at the margin

Sea of Islands

Sea of Tranquility

Smith's Sea

Sea of Fertility

Sea that is Known

Sea of Nectar

Sea of Clouds

Sea of Moisture
 

(All of these are dry lava plains, and nine are basins. The names of most of them date from 1651.)

 

Finding your way around the Moon:            2  -   Mountain Ranges


 

 In alphabetical order:  


   Latin Name
 		 English Equivalent
 

Montes Agricola

Montes Alpes

Montes Apenninus

Montes Archimedes

Montes Carpatus

Montes Caucasus

Montes Cordillera

Montes Haemus

Montes Harbinger

Montes Jura

 Montes Pyrenaeus

Montes Recti

Montes Riphaeus

Inner Montes Rook

Outer Montes Rook

Montes Secchi

Montes Spitzbergen

Montes Taurus

Montes Teneriffe

 

 

Agricola Range

Alps

Apennines

Archimedes Mountains

Carpathian Range

Caucasus Mountains

Cordillera Mountains

Balkan Mountains

Harbinger Mountains

Jura Mountains

Pyrenees

Straight Range

Ural Mountains

Inner Rook Mountains

Outer Rook Mountains

Secchi Mountains

Spitzbergen Mountains

Taurus Mountains

Teneriffe Mountains

 


 

Finding your way around the Moon:            3  -   Craters, Mountains and Valleys

The numbers on this lunar chart refer to the photographs listed in the table which follows:
 

 


No.
 		  Lunar feature No. Lunar feature No. Lunar feature
→

101

 

104

 

  

Mouchez + Pascal + Sylvester + Philolaus + Carpenter
Gerard + Dechen + Harding +
 Von Braun + Lavoisier

 

 		→

102

 

 

 

  

Anaximander + Desargues +
Pythagoras + Cleostratus

 →

103

 

 

 

  

Xenophanes + Markov + Volta + Regnault + Galvani  + Repsold


 

 
Observing the Moon
 

Terrae and Maria

When observing the Full Moon with the unaided eye, the first thing one notices is that it appears white with some darker patches. Ancient people thought that the Moon was a mirror reflecting the continents and oceans of the Earth, but they never agreed on whether the dark patches were the lands or the seas. In the 1590s, the Englishman William Gilbert made the first drawing of the Moon showing features we can vaguely recognise, but he named the dark patches as lands, and the lighter ones as seas. On his naked-eye drawing, a dark oval patch was named the "island" of Brittannia (sic). Sixty years later Giovanni Riccioli named it as a "sea", the Mare Crisium or Sea of Crises. By Riccioli's time primitive telescopes had revealed that the light areas were the lands or "Terrae",  and the dark areas were seas or "Maria" - it took many more years before the "seas" were found to be dry plains of solidified lava, and there was no liquid water on the Moon.

The Earth is 4.57 billion years old. The Moon is slightly younger, 4.425 billion. The Moon appears to have formed around the time the Earth's core was becoming solid and stable. Between 4.1 and 3.8 billion years ago, a high number of asteroids or minor planets left over from the formation of the Solar System were attracted by gravity into collisions with all the larger objects in the Solar System. The evidence of these impacts remains visible on all the terrestrial type planets and moons, but not the gas and ice giants whose surfaces we cannot see. The atmospheres on the Earth, Venus, and to a lesser extent Mars burned up all but the largest of these impactors. This cataclysmic event is known as the Late Heavy Bombardment or LHB.

The maria on the Moon were formed by collisions with asteroids or minor planets during the LHB. These impacts created large basins in the lunar crust which promptly filled with molten magma, which spread out onto the surface as lava flows, the basaltic nature of the magma causing the dark grey colour. Probably the first of these impacts created Mare Anguis, Mare Australe, Mare Fecunditatis, Mare Frigoris, Mare Insularum, Mare Marginis, Mare Nubium, Mare Smythii, Mare Spumans, Mare Tranquillitatis, Mare Undarum and Mare Vaporum (earlier than 3.92 billion years ago). After that, the Mare Crisium, Mare Humboldtianum, Mare Humorum, Mare Nectaris and Mare Serenitatis (3.92 to 3.85 billion years ago) were formed, then Mare Imbrium (3.85 to 3.8 billion years ago), and finally Mare Cognitum, Mare Orientale and Oceanum Procellarum (3.85 to 3.2 billion years ago).


Lakes, Marshes, Bays and Promontories

There are numerous smaller areas on the Moon that exhibit dark lava flows from strikes by less massive impactors. These are named as Lakes (there are 17, one example is the Lacus Mortis - Lake of Death), or Marshes (there are 6, one is Palus Epidemiarum - Marsh of Epidemics). There are 11 bays on the Moon, each being on the edge of a mare. They have names beginning with "Sinus", and the most spectacular is the Sinus Iridum (Bay of Rainbows). This feature has a promontory at each end of the "bay", the western one being "Promontorium Heraclides" and the eastern one "Promontorium Laplace". There are seven other Promontories on the Moon.


Mountains, Ranges, Valleys and Slopes

There are hundreds of mountain peaks on the Moon, many within craters, many as peaks in crater rims or mountain ranges, but only a few as isolated peaks protruding above flat lava plains. Two of the latter type are Mons Pico (2.4 kilometres high) and Mons Piton (2.25 kilometres high), which stand proudly isolated in the Mare Imbrium.

There are 18 mountain ranges, and 11 of them are around the margins of the maria, forming the circumferential boundaries of the basins created by the LHB impacts. For example, the impact that created the Mare Imbrium (Sea of Rains) threw up seven mountain ranges around its perimeter. These, starting from the north-west and moving clockwise, are the Montes Jura, Montes Recti, Montes Teneriffe, Montes Alpes, Montes Caucasus, Montes Apenninus, and Montes Carpatus. Some ranges are related to pyroclastic activity, such as the Montes Agricola, Montes Archimedes and possibly Montes Harbinger.

The Moon has some valleys, too, cutting through mountainous areas. There are eleven all told, but the most famous are the Vallis Rheita in the southern hemisphere, and the Vallis Alpes (Alpine Valley) and Vallis Schröterii (Schröter's Valley) in the northern. The latter two valleys are remarkable in that they both have a very fine sinuous rille running for almost their entire length, which is very challenging to detect.

There are some single fault scarps on the Moon, which cross flat plains like a gently sloping cliff 100 kilometres long or more. The two most notable are the Rupes Recta or Straight Wall (110 kilometres long), which crosses the Mare Nubium and is 300 metres high. Another is the Rupes Liebig (180 kilometres long), which is on the western margin of the Mare Humorum. The appearance of both of these slopes varies dramatically, depending on whether the Sun is rising or setting (see item  # 13   in the  Lunar Feature of the Month Archive - First Series ). The longest scarp is the Rupes Altai, which has a length of 480 kilometres, but is broken in places.

Rilles

The word 'rille' is German for 'groove'. These come in two types and are called Rima or Rimae (plural). One type is a V-shaped valley which can be straight or sinuous. Some are extremely long and begin at a small crater. They could possibly be collapsed lava tubes. There are many fine examples such as the Rima Marius, Rima Hyginus, Rima Hadley, Rimae Triesnecker and Rimae Prinz. The second type has two fault scarps two or three kilometres apart, running parallel often for hundreds of kilometres. Between them, the land has dropped down for a kilometre or so, leaving a flat floor between the scarps. On the Earth, similar features are known as grabens or rift valleys. Fine examples include the Rima Hesiodus, Rima Cauchy, Rimae Goclenius and Rimae Hypatia.


Volcanoes and Domes

Although no current volcanic activity has ever been observed on the Moon, there is widespread evidence that there has been considerable activity in the past. There are numerous shield volcanoes visible either singly, e.g. Kies Pi, in clusters of half-a-dozen or so (the Hortensius group) or in larger groups. The major group is the Marius Hills of more than a hundred. Many appear as low domes of about 10 kilometres diameter, and heights of a few hundred metres. At the summit of many can be found a volcanic vent, sometimes two, or a deep caldera as with Mairan T. The largest single volcanic complex is Mons Rümker with 22 volcanic craters. In addition, many craters and clefts are associated with ash vents which stain the nearby moonscape with dark patches of ash. Some good examples are in the craters Atlas and Alphonsus. The largest area of volcanic activity is north of the crater Schrӧter, where about 9000 square kilometres of lunar territory have been covered with dark-coloured ash associated with eruptions and pyroclastic flows. It is one of the darkest parts of the lunar surface (see item  # 35   in the  Lunar Feature of the Month Archive - First Series ).

 
Other Features

The lava plains that formed the maria cooled while still exhibiting waves and ripples. These solidified, and now appear as Dorsa (singular form "Dorsum"), popularly known as "wrinkle ridges". They are found in all the maria, but are particularly notable in the Mare Serenitatis and the Mare Imbrium. 


Craters, craterlets and walled plains

The Moon is covered by small, round depressions due to bombardment by asteroids, meteors and comets which hit the surface at high speed (roughly 25 kilometres per second) and explode, as their kinetic energy is converted instantaneously into heat, vapourising the impactor and blasting out a bowl-shaped crater. It is estimated that there are 300 000 impact craters on the Moon's near side that are larger than one kilometre across. Of course there are billions of smaller ones, ranging in size down to a metre or less.

The largest impactors struck the Moon early in its history, more than 3.8 billion years ago. These caused the major features we see today, particularly the dark lava plains called "mare" ("seas"). Over the eons the number of these impacts has reduced to near zero, and since astronomers have been looking at the Moon through telescopes, no new craters have been detected. Yet, occasionally monitoring cameras pick up a flash of light on the dark side of the Moon, so there are occasional meteor strikes, but not large enough to leave a visible crater.

Many craters had been forming on the Moon since the beginning, especially prior to the LHB which created the maria. There is much evidence on the Moon of ancient craters being swamped by molten lava surging across the surface after an LHB strike, so that they are almost or completely covered. Their presence can still be faintly seen, and they are called "ghost craters". One example is Stadius. Often, the lava surged around an existing crater without penetrating it. Other times, the lava forced a breach in the crater wall and then swept in, flooding the interior. Good examples of this are Fracastorius, Letronne and Prinz.

Early selenographers such as Hevelius drew their maps showing the craters as hollow mountains, as they thought that they were volcanic calderas similar to those on Earth. Hevelius named them all as mountains, e.g. he named one feature "Mount Sinai", but Riccioli, realising that it was a cavity in the surface, named it "Tycho". Only a few people in the seventeenth century thought that these "cavities" might be caused by impacts from space, but Robert Hooke experimented by dropping lead balls into softened pipeclay and thought it might be true. At the time, no-one knew about objects flying through interplanetary space at random. The cavities were given their proper name "crater" (from the Latin word for "cup") in 1791 by Johann Hieronymous Schröter - he also gave us the word "rille" (German for "groove").

Craterlets have a diameter of less than 10 kilometres, and are generally bowl-shaped with a raised rim and a small ejecta blanket around the outside of the rim. Craters larger than this, but less than 150 kilometres across, often have a cluster of mountains in the centre. This is because the initial impact sends down a shock wave to the bedrock, which rebounds back up. It fractures and lifts the newly-formed crater floor, creating the mountains more or less in its centre. Huge amounts of melted rock are created by the impact, which cover the surface all around the new crater like a darker basaltic halo. Quite often, the initial blast sends rocks and boulders as big as flying mountains skittering across the lunar surface for hundreds (sometimes thousands) of kilometres, leaving great gouges in the moonscape. These are what cause the light-coloured so-called "rays" that are seen around craters such as Tycho, Copernicus and Kepler. Such craters often exhibit areas around their floors where the walls have slumped down in landslides, creating spectacular terraces.

It is often seen in such craters that the fissures in the newly fractured floor release the pressure on the superheated bedrock, which then becomes liquid and expands. It forces its way to the surface as molten magma, oozing out of the fissures and spreading out over the new bowl-shaped floor which becomes dark lava when it cools. Sometimes, only a small amount of lava emerges, as in the crater Copernicus; at other times it covers the entire crater floor, often completely swamping any mountains on the floor, as in the crater Plato, which Hevelius called "Lacus Niger" (Black Lake). If such flat-floored craters are larger than 80 kilometres in diameter, they are called "walled plains". Generally, the rising magma fills the new crater up to a level equal to the surrounding lunar surface or slightly lower or higher. One crater in which the upwelling lava filled it right up to the top of its raised rim and then overflowed down the outside slopes to create a level plain beyond, is Wargentin. It gives the appearance of a plateau or tableland. Large walled plains include Ptolemaeus, Alphonsus, Hipparchus, Endymion, Plato, Petavius, Posidonius, Grimaldi, Clavius and Humboldt.

Sometimes a flying mountain ejected from an impact will bounce across the surface, leaving a trail of secondary craters. These are called "Catena" (Latin for "chain"), and two of the best known are the Catena Davy and the Catena Abulfeda.
 

Basins

The largest crater on the near side of the Moon is Bailly (see item  #64   in the  Lunar Feature of the Month Archive - First Series ). Although it was a major impact early in the Moon's history and is 303 kilometres in diameter, its floor was not fractured and no mountains were thrust up. There are, though, a few low ridges. No lava emerged to level out its floor, and over the eons Bailly has been severely battered by thousands of impacts of various sizes, so that it has become described in Wikipedia as a "field of ruins". Bailly is regarded not so much as a very large crater, but as a small "basin". Most basins are much larger, and all are formed by huge impacts. There are 29 all told, and some of the largest are named as "Mare" (singular, "Maria" is the plural form). Nine of the Maria listed in the table above are basins.

 

NOTE:
 

In the above section, reference is made to many named lunar features. A majority of these are pictured in the following Archive, where they can be examined. To locate their numbers in the Archive, find their names in the Tables and Charts that have preceded this section. For example, you may wish to look at a picture of the crater known as Philolaus. Reference to the Table preceding this section will show that an image of Philolaus appears in item  # 101 .   Simply scroll down to  101  to see the image which includes that crater.

 

The waxing gibbous Moon at 9:25 pm on August 1, 2017.

 

The photograph above shows the Moon when approximately nine days after New, just after First Quarter. The cluster of two large craters with a large, circular walled plain shown in detail below can be found in the northern hemisphere, near the top left corner. It is close to the line between the sunlit area and darkness. This line is called the 'terminator' and it moves in a westerly direction across the moonscape at the latitude of the features shown below at a speed of 16 kilometres per hour.

 

This image was taken at 7:50 pm on July 2, 2017. 63% of the Moon was illuminated, 1.7 days after First Quarter.

 
 


The image above shows a spectacular area in the south-eastern end of the Mare Imbrium (the Sea of Rains). It is a dry lava plain containing wrinkle ridges (Dorsa); a large bowl-shaped impact crater called Autolycus, a larger bowl-shaped impact crater called Aristillus with a cluster of mountains in its centre; a walled plain called Archimedes with spectacular terraces around its inside walls; a ghost crater; a line of cliffs 85 kilometres long; ranges of mountains; isolated peaks and hills; clefts; rilles; a large pyroclastic area; dozens of tiny craterlets and, to top it off, the Apollo 15 landing site next to Mount Hadley, where David R. Scott and James B. Irwin were the seventh and eighth astronauts to walk on the Moon (they took a lunar rover with them so that they could ride to Hadley Rille).
 

 

This image was taken at 7:16 pm on August 1, 2017.  On the Moon, the Sun was slightly higher in the sky than in the previous images.  67% of the Moon was illuminated, two days after First Quarter.
 
 

A rotatable view of the Moon, with ability to zoom in close to the surface (including the far side), and giving detailed information on each feature, may be downloaded  here.  A professional version of this freeware with excellent pictures from the Lunar Reconnaissance Orbiter and the Chang orbiter (giving a resolution of 50 metres on the Moon's surface) and many other useful features is available on a DVD from the same website for 20 Euros (about AU $ 33) plus postage.
 

Above is a photographic animation from Wikipedia Commons showing the lunar phases. It also shows the Moon's wobble or libration, and how its apparent size changes as it moves from perigee to apogee each month. Such downloads are freeware, although the authors do accept donations if the user feels inclined to support their work.

Technical information :


The following pictures in this Archive were taken at Starfield Observatory, Nambour, Queensland, Australia through an Alluna Ritchey-Chrétien RC-20 reflecting telescope, built to order in Germany. The aperture is 508 mm and the focal length is 4080 mm. The focal ratio is therefore f/8.  Most images but not all were taken using a 2x Tele Vue Powermate to increase the image scale. The camera used is a ZWO ASI 290MM with a red filter. It is a video camera and captures a video stream from which the clearest frames are extracted and then stacked to produce the final image. The software used includes SharpCap 2.9, FireCapture V2.5, AutoStackkert! 3.1.4, RegiStax V6.1.08, Planetary Imaging Pre-processor (PIPP) V2.5.9, AstroSurface V3, and Adobe Photoshop V8.0.

We can work out the scale of the images in the Archive below by using the first picture in the  Lunar Feature of the Month Archive - First Series  ( #1 Clavius )  as an example:

The equatorial diameter of the Moon = 3476 kilometres. On the night the photograph of Clavius was taken, 2 August 2017, the Moon was at apogee (its monthly maximum distance from Earth, in this case 405 053 kilometres). Its angular diameter on the sky at that time was 29.5 arcminutes.

Clavius has a diameter of 225 kilometres, so its angular diameter on that occasion can be determined in proportion from that of the Moon:   3476 km : 225 km :: 29.5 arcminutes : x arcminutes   ( 3476 is to 225 as 29.5 is to  x ,  or  225 multiplied by 29.5 divided by 3476 equals  x arcminutes ).

Simple arithmetic gives the angular diameter of Clavius ('x arcminutes') on that night to be 1.91 arcminutes or 114.57 arcseconds. If the image is printed to fill an A4 sheet in landscape format, and examined from a normal viewing distance of 28 centimetres or 11 inches, the image of Clavius will subtend an angle of 64 degrees or 230 400 arcseconds at the eye. To find the magnification of the image at that distance, we can calculate by which number 114.57 arcseconds must be multiplied to arrive at an answer of 230 400 arcseconds.

230 400 divided by 114.57 equals 2011. Therefore, to examine an A4 reproduction of  #1 Clavius  at a normal reading distance is equivalent to viewing it through a telescope with a magnification of 2011 times ( magnification = 2011x ). Such a view is what one would see through a spacecraft window if orbiting the Moon at an altitude of 200 kilometres.  Those pictures requiring a larger field, such as maria or lengthy mountain ranges, have been taken with the 2x Powermate removed. Examples of this procedure are the two images of Mare Imbrium (  #12  ) and also one of the Montes Apenninus (  #15  ). This results in a field of view four times larger in area, but with a magnification of only 1005x, similar to orbiting the Moon at an altitude of 400 kilometres.

The techniques outlined above enable very fine details on the Moon and planets to be detected in the final images. That of  #1 Clavius  contains hundreds of sub-kilometre craterlets. Ten of them are indicated by yellow lines in the enlargement immediately below. Some are tinier than 750 metres diameter, which is approaching the minimum size detectable from Earth with an aperture of 500 mm under optimum seeing conditions.


Clavius  (central section).
 

The image of  #25 Gutenberg  in the  Lunar Feature of the Month Archive - First Series  contains hundreds of sub-kilometre craterlets around the crater Goclenius.  Ten of them are indicated by yellow lines in the enlargement seen below. The image was acquired at 5:19 pm on 18 July 2018.
 

Goclenius (55 kilometres X 54 kilometres). The easiest sub-kilometre craterlet to find in this image is located inside Goclenius, 7 kilometres north of that walled plain's geometric centre. It is shown between two blue lines. Careful measurement of Lunar Reconnaisance Orbiter images shows that the diameter of that craterlet is about 650 metres.

 

 

 

Archive   -   Second Series

 

 

 

Generally speaking, most telescopic observers have their favourite lunar features, most of which have already appeared in the first hundred images in this Archive. Yet there are many more interesting features on the Moon that for one reason or another attract little attention. Whereas craters near the Moon's centre as seen from Earth appear as if from a spacecraft flying overhead looking vertically down, craters around the Moon's limb or 'edge' are seen in prl which means that features in the craters' interiors such as rilles cannot be seen. Also, craters near the limb may be in the zone of libration, which means that they spend some time each month out of sight from Earth. Features on the near side of the Moon are visible for up to two weeks each month if they are not close to the limb, but features near the limb can only be easily seen if there is a favourable libration bringing them into view at a time when the lighting of the area permits them to be seen. Features near the limb are therefore much more difficult to observe. Those near the eastern limb can only be observed for a few days after New Moon, and a few days after Full Moon. Those near the western limb can only be observed for two or three days before Full Moon, and two or three days before New Moon, at dawn. Such observing sessions need to be coordinated with the Moon's libration using software such as the Virtual Moon Atlas.

In November and December in 2024 ( items  # 99  and  # 100 of the  Lunar Features of the Month Archive - First Series ), the heavily cratered area to the south-east of the Moon's North Pole was described, as it is an area that is close to the lunar limb and therefore greatly foreshortened and affected by libration. In the following months we will again begin at the North Pole, but this time we will travel south around the horizon to the Moon's equator, which is an area often overlooked by lunar observers. We will become acquainted with numerous craters and walled plains which are usually out of sight. Some can only be photographed within a few hours of Full Moon, when the features not near the limb have fewer or no shadows and so the pictures appear lacking in detail and contrast. To assist in recognising these features, they were photographed on 22 May 2024 and 23 May 2024, when libration was very favourable. Full Moon occurred at 11:54 pm on 23 May, 2 hours and 48 minutes after the last photograph. Occasional clouds interrupted the sequence three times - earlier photographs of these areas under almost identical conditions have been inserted into the sequence for the sake of continuity. This set of images began in January 2025 and will run until the following August.

Early observers of the Moon named some of these features, but they neglected many of those close to the limb. Later observers using better equipment added the names of modern scientists and philosophers. This is why we will meet in this sequence of images some well-known names such as Balboa, Vasco da Gama, Pascal, Dalton, Stokes, Langley, Galvani, Bunsen, Struve, Volta, Babbage and Lavoisier, and from the twentieth century Aston, Rontgen, Nernst, Lorentz, Einstein, Bohr, Eddington, Russell and Von Braun. The crater commemorating Wernher von Braun, the German-American rocket pioneer, was named by the International Astronomical Union (IAU) in 1994.

 

 


 These two images of the North Pole area are from the  Lunar Feature of the Month Archive - First Series  ( item   # 99  ), and are included here to assist in matching their lunar features with those shown in item  # 101  following:

 


The two images below are close-ups of the area around the lunar North Pole (shown with a blue asterisk).

 

This image was taken at 7:25 pm on 4 October 2022.



 

 

The two new medium-field images immediately following are included here to assist in matching up the details in six images that appeared in item  # 99  in the  Lunar Feature of the Month Archive - First Series  with those above, and those that follow in item  # 101 below:
 


 

This image was taken at 9:27 pm on 31 July 2023. The angle of view is twice that of the previous pair above. The Sun was very high in the Moon's sky, causing the lighting to be flatter with much smaller shadows. Full Moon occurred 32 hours after this image was taken.






Note the light-coloured streaks radiating for hundreds of kilometres from the 51-kilometre crater Anaxagoras (centre). As most of these 'rays' are to the north-east, east and south-east of the crater, it is obvious that the incoming impactor was travelling at a low altitude from the west (left-hand) side.
 
 

 



 Key to features 101 - 104 below.
 


101:   January  2025

GROUP A

 This month's feature is the rugged area adjoining the Moon's North Pole. It extends west to longitude 50º west and south to latitude 65º north. It includes an ancient walled plain called Mouchez, and a much more recent crater called Philolaus. This is the first in a sequence of 50 images to be presented this year, covering the zone of libration from the North Pole around the north-western limb of the Moon to the Equator. As the sequence progresses, the camera will start from the walled plain Hermite and then move west, following the Moon's north-western limb in a southerly direction until we reach the lunar equator in the vicinity of the crater Riccioli. Features recorded such as craters will move to the right as the sequence continues, as the image frame moves to the left. The average width of each image will be 265 kilometres.
 

This area adjoins that shown as image  # 99  in the  Lunar Features of the Month Archive - First Series.  This image was captured at 9:36 pm on 22 May 2024.

 




 

i:    The eastern walls of the 110 kilometre diameter walled plain Hermite are only 50 kilometres from the Moon's North Pole itself.  Hermite is in the zone of libration, as is the nearby 58 kilometre walled plain Sylvester .  Both of these features are about 3.8 billion years old, or middle-aged as lunar features go.  South of these two, the lunar surface has been battered by eons of impacts, the walled plains Poncelet  (70 kilometres), Mouchez  (83 kilometres) and Anaximenes  (80 kilometres) showing considerable degradation. On the other hand, the crater-plain Philolaus (71 kilometres) is much more recent, its age being less than 1.1 billion years. The rim of Philolaus remains sharply defined. A small part of the floor has been flooded with lava, but the rest of the floor is very rugged, with numerous hills and four clusters of mountains. The interior crater walls show many land slips (particularly on the southern or near side), which now appear as terraces.
 

Philolaus

Philolaus of Croton (470-385 BCE), born in southern Italy, moved to Greece and learned of the theories of Empedocles. Becoming a follower of Pythagoras, he joined the Pythagoreans at Thebes, between Athens and Delphi. Like other Greek philosophers, he was devoted to perfection. The circle was the perfect plane figure, and the sphere the perfect solid figure. He believed that the number ‘10’ was perfect, as it was the sum of the first four integers (1 + 2 + 3 + 4). Therefore there should be 10 celestial bodies, but he could see only nine – the Sun, Moon, the Earth, the five naked-eye planets, and the sphere of fixed stars (counted as one item).

Aristotle tells us that this was the reason that Philolaus decided that there must be a tenth planet, which he called the Antichthon or ‘counter-Earth’. He set all of these bodies, including the Sun, in orbit around Hestia, the central fire of Pythagoras, which people could never see because the side of the Earth on which they lived was always facing away from it. He went on to say that the counter-Earth was also never seen, because it was on the opposite side of the central fire from the Earth, and so was always hidden from view. This erroneous cosmology was based more on philosophical principles and wishful thinking than on real astronomical observations, but it had one remarkable feature. For the first time in history, it  described the Earth as one of a family of two planets moving in circular orbits, though not around the Sun, but around Hestia, the central fire. It was the first suggestion of a planetary system revolving around a central body, with its various components also rotating upon their axes. Two thousand years later, Nicolaus Copernicus would analyse the ideas of Philolaus when developing his own truer conceptions.

Philolaus has his own crater 370 kilometres east of Pythagoras, in the same northern part of the Moon where we also find craters named after other famous Greek philosophers such as Anaximander, Anaxagoras, Plato, Eudoxus, Calippus, Aristoteles, etc.
 


This area adjoins the left-hand (western) side of the pair above.  This image was captured at 9:46 pm on 22 May 2024.

 

ii:    In this image, the craters Poncelet and Philolaus are now on the right-hand side, and Anaximenes is in the centre.  The walled plains Pascal (106 kilometres) and Poncelet C (67 kilometres) have now come into view, as has the more recent crater Carpenter (40 kilometres).  A small craterlet called Anaximander H (9 kilometres) can be found near the lower left-hand corner.  A huge walled plain called Brianchon (146 kilometres), which lies in the zone of libration, appears in this image as a dark void, but when it is illuminated one day later (see next image), the far ramparts of Brianchon are revealed, and the summits of small hills in the centre of the floor catch the light of lunar dawn.
 

Pascal

Blaise Pascal (1623-1662) was a French mathematician, physicist, inventor and philosopher. He was also a contemporary of René Descartes. In 1642 aged not yet 19, he built mechanical calculators that could add and subtract. Eight of his "Pascalines" still exist in museums today.


 

This area shares many features with the four images above. This one was captured at 8:05 pm on 23 May 2024.

This image also includes most of the ancient compound crater Desargues, which is an 86 kilometres diameter walled plain which has been struck by two later impactors.  Desargues is shown in full in item  # 102  below.

 

 

 

102:    February  2025

GROUP B

This month's feature is a rugged area to the south-west of the Moon's North Pole. It extends west to longitude 63º west and south to latitude 57º north. It includes an ancient walled plain called Anaximander and a spectacular crater called Pythagoras.
 



This area shares many features with the six images immediately above. This one was captured at 9:51 pm on 22 May 2024.


 



iii:    The conjoined crater plains Anaximander (68 kilometres), Anaximander B (78 kilometres) and Anaximander D (92 kilometres) produce a large flat area to the left (west) of the clearly defined crater Carpenter (60 kilometres) which is obviously much more recent. The tiny craterlet marked '1' in white in this image and the one below serves to link the two images.

 
Anaximander

Anaximander (610-546 BCE), regarded as the father of astronomy, was a contemporary of Thales and followed his teachings. He agreed that everything had a common origin, but did not agree that it was water. Instead, he said that everything came from ‘ἄπειρον’ (‘apeíron’, which means ‘the original, indefinite, limitless principle’). From this, four elements of earth, water, air and fire were formed, from which everything else was made. Anaximander was one of the first to differentiate between ‘fixed stars’ and planets. He described the Pole Star, and said the path of the Sun, Moon and planets was tilted to what we call the ‘celestial Equator’, a phenomenon now called the ‘obliquity of the Ecliptic’.

He believed that the Earth was at the centre of the universe, and so stated that, being in such an exalted position, it would have no need of support. He took this further to postulate that our planet was a squat cylinder with a length one-third of its diameter, not floating on Thales’ ocean, but hanging motionless, suspended in space without requiring any physical means of support (right). The world as we know it occupied the upper end. This idea of a free-floating Earth was a marked advance, as all previous cosmogonies described a world that needed to be held up by something, such as pillars or water. However, Anaximander did place the floating Earth fixed at the centre of the universe. He claimed that the Earth was surrounded by an opaque crystalline black sphere that enclosed the air and weather. The celestial bodies moved on this sphere. Outside the sphere was a region of fire. Stars were tiny holes in the sphere through which the fire behind could be glimpsed.

 

 

This area is dominated by the great impact crater of Pythagoras which is 129 kilometres in diameter. It is a middle-aged crater, and it struck the Moon near the north-eastern corner of a much more ancient walled plain called Babbage.   This image was taken at 9:57 pm on 22 May 2024.


 

 

iv:    Pythagoras has a diameter of 129 kilometres. It has a lava-filled flat floor with three spectacular groups of mountain peaks in its centre. The walls of Pythagoras show some of the most spectacular terraces on the Moon. There is a four kilometre craterlet on the northern part of the floor, and a five kilometre craterlet has struck one of the northern terraces.  Babbage is a rectangular feature with a distance across the diagonals of 150 kilometres. Its walls have been worn down by small impactors raining down for the last four billion years until they have become hardly recognisable. When the Pythagoras impactor arrived, great quantities of melted rock and rubble were catapulted into Babbage and can be seen overlying the north-eastern quarter of Babbage's floor. The rock melt covering the Moon's surface to the west (left) of Pythagoras indicates that the impactor arrived from the east and travelled at a low level before striking the surface.

Just catching the morning Sun at the top of this image are numerous craters whose walls are illuminated, but whose interiors remain in darkness. Two of these are Cleostratus (63 kilometres) and Boole A (56 kilometres).  Two other crater plains identified in this image are Oenopides (68 kilometres) and South (108 kilometres). Both of these are far from the terminator and are well lit.


 

This area shares many features with the two images immediately above. This one was captured at 8:08 pm on 23 May 2024, the evening after the previous images.

 

 


v:    The Moon is now less than 4 hours from being Full, and three new craters have become visible near the north-western limb. They are Boole (63 kilometres),  Boole H (75 kilometres) and Cremona (86 kilometres). All three are in the zone of libration.


Pythagoras

Pythagoras of Samos (ca. 570-495 BCE) was the first person to describe himself as a philosopher (lover of wisdom). He travelled widely, seeking knowledge from Egypt, Babylon and possibly India, before settling in Croton, Italy. The first true mathematician, he is best known for his famous geometrical theorem regarding right-angled triangles:  "The square on the hypotenuse of a right-angled triangle equals the sum of the squares on the other two sides."  He began a religious brotherhood called the Pythagoreans, to promote his philosophies. They believed that numbers are the ultimate reality, and everything is related to mathematics. It was he who gave the name kosmos (order, or the interconnectedness of all things) to the universe. He had observed that the North Star appeared higher in the sky when he journeyed north, and lower in the sky when he went south, and came to the conclusion that the Earth is not flat, but is shaped like a sphere. This was a major advance. Since his time, no sensible person has ever believed in a flat Earth, but he also taught that all the planets revolve around a central point with uniform, circular motion, and that the stationary globe of the Earth was located immovable at this central point.         

Pythagoras then took this thinking further, postulating that the globe of the Earth is surrounded by a rotating series of eight concentric, crystalline spheres of impenetrable hardness, on which are fixed objects that shine, namely the Sun, Moon, planets and stars. As all the stars appeared to be ‘fixed’ in position, they must all be attached to the furthermost sphere, which must be black. The first seven spheres needed to be transparent so that the stars on the black sphere beyond could be seen. They were all nested together, and moved as one, although they each had small individual motions. Pythagoras’ ideas, quite novel in the sixth century BCE, had a major influence on Plato, and, through him, on all western thought. In his geocentric view of the universe, Pythagoras believed that the concentric crystalline spheres were separated by musical intervals (tones and semitones), and generated musical harmonic scales. He called this the music of the spheres, and claimed to be able to hear it. In his concept, the musical interval between the Earth (Terra) and the fixed stars (Signifer) had to be a diapason – the most perfect harmonic interval. The individual steps in the sequence were: Earth to the sphere of the Moon = 1 tone; Moon to Mercury = 1 semitone; Mercury to Venus = 1 semitone; Venus to Sun = 1 tone + 1 semitone (3 semitones); Sun to Mars = 1 tone; Mars to Jupiter = 1 semitone; Jupiter to Saturn = 1 semitone, Saturn to the sphere of fixed stars = 1 tone + 1 semitone (3 semitones). The sum of these intervals equals seven tones, the interval covered by the eight notes in an octave. Pythagoras later produced a novel idea that the Earth might not lie at the centre of the universe, but might itself be in motion, revolving around a ‘central fire’ called Hestia, which was always hidden from us by the bulk of the Earth. The Sun would be a shiny disc also revolving around Hestia, and reflecting the central fire to the Earth.

 

 

 

103:    March  2025

GROUP C
 

 This month's feature is the area at the extreme north end of the Oceanus Procellarum (Ocean of Storms). It extends west to longitude 80º west and south to latitude 46º north. It includes an ancient walled plain called Xenophanes and a much more recent crater called Markov.
 

 

This image shows the features to the west of those in the previous image. It was taken at 10:03 pm on 22 May 2024.


 
vi:    The crater plains Cleostratus and Oenopides seen near the left margin of the image just above paragraph ' v ' above, now appear at the right margin of this image. Fresh moonscapes around the crater Markov (41 kilometres) and the walled plain Repsold (108 kilometres) have now come into view. The large flat areas in this and subsequent images are part of the extensive lava plain known as the Oceanus Procellarum (Ocean of Storms), which has an area of 2.1 million square kilometres. The complete wall of the large crater plain Xenophanes (121 kilometres) is visible, but its floor remains in shadow except for the illuminated summits of a mountainous spine running north-east to south-west and an illuminated summit on the northern wall of a 35 kilometre crater-plain on the west half of Xenophanes' floor (seen below). The upper left corner of this image shows a black void which is the dark interior of the walled plain Volta (113 kilometres). The outside of the curved southern wall of Volta is seen clearly.


 Xenophanes

Xenophanes of Colophon (c. 570 - c. 478 BC) was a Greek philosopher, theologian and poet from Ionia who travelled throughout the Greek-speaking world in early classical antiquity. Only fragments of some of his works survive in quotations by later philosophers and scholars. Xenophanes is remembered as one of the most important philosophers in the century before Socrates. A highly original thinker, he sought explanations for physical phenomena such as clouds and rainbows based on actual observations, without references to divine or mythological suggestions or ideas. He distinguished between different forms of real knowledge and mere beliefs, an early instance of epistemology.

 
 

 

The same area of the Moon, photographed at 8:12 pm on 23 May 2024.

 

vii:    In this image, taken 22 hours later, the whole walled plain of Volta has been filled with sunlight, revealing a mountain and two craters on the floor, and another crater, Volta D (20 kilometres), which has impacted on the south-western wall. The far (northern) wall of Volta has been impacted by the secondary crater Regnault (48 kilometres), which also has been revealed by the rising Sun.  The left side of this image shows part of the complex floor of the crater-plain Repsold (108 kilometres) which is shown in full in the next four images.
 
 



 This image shows the features to the south of those in the previous image. It was taken at 10:11 pm on 22 May 2024.

 
 


 

viii:    In this image, the walled plain Volta was still in shadow, as was nearby Galvani (80 kilometres).  The recent cone crater Dechen (12 kilometres) is isolated in the Oceanus Procellarum.  Repsold has a squarish shape, each diagonal approximating 108 kilometres. Its flat floor has numerous craterlets, and is crossed by several V-shaped rilles and some grabens (rift valleys), but these can only be observed a day later if the libration allows. Repsold's north-west corner has been struck by a large impactor, creating a secondary crater called Repsold G (44 kilometres). Near the left margin is a small cone-shaped crater called Repsold T (13 kilometres). It is indicated on this image and three others by the letter T, and can be used to link this image with others in this Group and the next.


 

The same area of the Moon, photographed at 8:16 pm on 23 May 2024.


 


 


ix:    The rising Sun which has illuminated the interiors of the craters Volta and Regnault has also revealed details in the interiors of Galvani, Gerard Q Inner and Outer, Repsold and Repsold G. The previously unseen craters Stokes (51 kilometres), Langley (60 kilometres), McLaughlin (79 kilometres) and McLaughlin B (43 kilometres) have also become visible.
 

Galvani

Luigi Galvani (1737-1798) was an Italian physician, physicist, biologist and philosopher who studied what was then called ‘medical’ or ‘animal electricity’. This field emerged in the middle of the 18th century, following electrical researches and the discovery of the effects of electricity on the human body by various European scientists in the.1770s.

In 1780, using a frog, he discovered that the muscles of dead frogs' legs contracted or twitched when struck by an electrical spark. This was an early study of bioelectricity, following experiments by John Walsh and Hugh Williamson. He concluded that every animal cell has an electric potential, and that biological electricity was distributed around a body by ‘animal electric fluid’. This fluid existed only in living creatures, so it was believed for a time that electricity was only to be found in living beings.
 

Volta

Alessandro Giuseppe Antonio Anastasio Volta (1745-1827) was an Italian chemist and physicist who was a pioneer of electricity and power, and is credited as the discoverer of methane. At first, he accepted ‘animal electricity’ and was among the first scientists who repeated and checked Galvani’s experiments. However, he began to doubt that the contractions were caused by specific electricity intrinsic to the animal’s legs or other body parts. He experimented with various chemicals similar in nature to the so-called ‘animal electric fluid’ and invented the ‘voltaic pile’ (a multi-cell battery) in 1799. He therefore proved that electricity could be generated chemically in a laboratory and debunked the theory that electricity was generated solely by living beings. Volta's invention sparked a great amount of scientific excitement and led others to conduct similar experiments, which eventually led to the development of the field of  electrochemistry.

Volta drew admiration from Napoleon Bonaparte for his invention, and was invited to the Institute of France to demonstrate his invention to the members of the institute. Throughout his life, Volta enjoyed a certain amount of closeness with the emperor who conferred upon him numerous honours. Volta held the chair of experimental physics at the University of Pavia for nearly 40 years and was widely idolised by his students. The SI unit of electric potential, e.g. “240 volts” is named the ‘volt’ in his honour.

Galvani did not agree totally with Volta’s discoveries, but both men respected each other and corresponded regularly. When Volta built the first electric circuits using battery power, he gave a nod to his rival by coining the term “Galvanism” for a direct current of electricity produced by chemical reaction. 

 

 

 

 

104:    April  2025

GROUP D
 

This month's feature is a rugged area on the lunar limb about halfway between the Moon's North Pole and its Equator. It extends west to longitude 87º west and south to latitude 37º north. It includes an ancient walled plain called Lavoisier and a much more recent crater called Harding.

This image was taken at 10:18 pm on 22 May 2024.

 
 

This image shows the features to the south of those in the image described in paragraph ' ix: '.


 

This image shows the features to the west of those in the previous image. It was taken at 8:19 pm on 23 May 2024.

 



 

x:    This image adjoins the one listed as ' ix: ' in  GROUP C. Both include the small crater marked with a letter T (Repsold T) and the crater Dechen. The walled plain Gerard (91 kilometres) has a very rugged floor, with numerous hills and many craterlets with diameters between 3 and 4 kilometres. Adjoining the north-west wall of Gerard is a huge walled plain called Gerard Q (192 kilometres). It is known as Gerard Q Outer, for there is in its centre a circular feature called Gerard Q Inner, which has a diameter of 67 kilometres). This feature is volcanic and has in its western half extremely rugged hills with floor fractures, while in its eastern half we find a dark-coloured flat area which was once a lake of molten basaltic magma.

South of Gerard is a flat-floored crater-plain named Von Braun (61 kilometres). West of it is a similar but smaller crater called Lavoisier E (49 kilometres). Like many others in their vicinity, the floors of these two craters contain many rilles and grabens.  Isolated in the Oceanus Procellarum are Harding (23 kilometres) and Dechen.


 

This image shows the features to the south-west of those in the previous image. It was taken at 10:29 pm on 22 May 2024.


 




xi:    The largest crater-plain in this image is Lavoisier (90 kilometres) which, like its neighbours Von Braun, Lavoisier A, Lavoisier E, Lavoisier H, Bunsen, Volta, Repsold and Repsold G, has a flat floor which is crossed by numerous rilles and grabens.  Most other craters in the area do not have these volcanic features. There is an interesting feature just north of the centre of Lavoisier. It is a 5 kilometre diameter unnamed concentric cone crater, in which one impactor has created the original crater, and a second impactor has landed in the exact centre of that crater, giving the impression of a bulls-eye or doughnut. Such concentric craters are quite rare, but two which have been photographed and can be found on this website appear as images   #14  (Hesiodus A) and   #41  (on the eastern side of the Humboldt walled plain) in the  Lunar Features of the Month Archive - First Series.  

 

This image shows the features to the west of those in the previous image. It was taken at 8:26 pm on 23 May 2024.


 



 

xii:    The rising Sun which has previously revealed the craters Gerard, Harding and Von Braun (see image ' xi: ') has now illuminated the craters Bunsen (53 kilometres), Bunsen A (39 kilometres), Bunsen B (20 kilometres, Bunsen C (18 kilometres), Lavoisier E (49 kilometres) and Avicenna G (26 kilometres).  All six of these are in the zone of libration. Lavoisier A (28 kilometres) has a rugged floor with numerous rilles, and one major terrace which runs for a fifth of the inner circumference.

 
Bunsen

Click  here  for a pdf file telling the remarkable story of how Robert Bunsen and Gustav Kirchhoff discovered the mysterious "barcode of the stars" in 1859, which enabled us to find out what stars are made of.

 
Gerard

Alexander Gerard (1792 - 1839) was a Scottish army officer in India, and an early surveyor and explorer of the Himalayas. During the surveys he made in the Himalayas, he ascended heights previously believed to be inaccessible, and penetrated into Tibet as far as the frontier with China. Our earliest information of the structure of the Himalayan ranges come from his explorations in 1821, when his team climbed to heights of up to 19 400 feet  (5913 metres).


Harding

Karl Ludwig Harding (1765-1834) was a German astronomer who discovered the minor planet Juno in 1804. It was the third asteroid to be found, after Ceres (by Piazzi) and Pallas (by Olbers). In addition to Juno, he discovered three comets and the variable stars R Virginis, R Aquarii, R Serpentis and S Serpentis. He also found some new nebulae, one being the Helix Nebula.


Von Braun

Wernher Magnus Maximilian Freiherr von Braun (1912-1977) was a German-American aerospace engineer. He was the leading figure in the development of rocket technology in Nazi Germany, and later a pioneer of rocket and space technology in the United States.

As a young man, von Braun worked in Nazi Germany's rocket development program. He helped design and co-developed the V-2 rocket at Peenemünde during World War II.  A V-2 became the first artificial object to travel into space on 20 June 1944. Following the war, he was secretly moved to the United States, along with about 1600 other German scientists, engineers and technicians. He worked for the United States Army on an intermediate-range ballistic missile program, and developed the rocket that launched the United States' first space satellite Explorer 1 in 1958. In 1960, his group was assimilated into NASA, where he served as director of the newly formed Marshall Space Flight Center and as the chief architect of the Saturn V super-heavy-lift launch vehicle that propelled the Apollo spacecraft to the Moon from 1968 to 1972. In 1967, von Braun was inducted into the National Academy of Engineering, and in 1975, he received the National Medal of Science.

Von Braun was a controversial figure, widely seen as escaping justice for his awareness of Nazi war crimes due to the Americans’ desire to beat the Soviets into space during the Cold War. He was decorated by Adolf Hitler twice. Despite his faults, he can be described as the “father of space travel”, the “father of rocket science”, or the “father of the program to put a man on the Moon”.


Lavoisier

By the second half of the eighteenth century, the ancient idea of the universe being composed of four ‘elements’ (earth, water, air and fire) had been completely laid to rest. Robert Hooke had shown a century earlier that fire was not an element but a chemical process. The metals of copper, lead, gold, silver, iron, carbon, tin, sulphur, mercury, zinc, arsenic and antimony had been known since antiquity but were thought to be merely ingredients of earth. Now they were understood to be individual elements in their own right, so earth was not an element but many diverse compounds. Phosphorus had been recognised in 1669, and cobalt, platinum, nickel, bismuth and magnesium were isolated by 1755. Hydrogen was first artificially produced in 1671 by Robert Boyle (1627-1691), who discovered and described the reaction between iron filings and dilute acids, which results in the production of a gas. In 1766, Henry Cavendish (1731-1810) was the first to recognise hydrogen as a discrete substance, by naming the gas from the metal-acid reaction “inflammable air”, as it ignited explosively if a flame was introduced. He found in 1781 that the gas produced water when burned. He is usually given credit for the discovery of hydrogen as an element, but it remained without a name.

Oxygen was first discovered by the Swedish pharmacist Carl Wilhelm Scheele (1742-1786). He produced oxygen gas by heating mercuric oxide and various nitrates in 1771-72. Scheele called the gas “fire air” because it was the only known supporter of combustion, and wrote an account of this discovery in a manuscript entitled Treatise on Air and Fire, which he published in 1777. In the same period, the English clergyman Joseph Priestley (1733-1804) used sunlight to heat mercuric oxide and saw that candles burned brighter in the gas produced and breathing it made him feel light-headed. Antoine Lavoisier (1743-1794) was also studying this gas and named it oxygen (ὀξύς oxys meaning “acid” or “sharp tasting” and γενής genes  meaning “creator”). The discovery of nitrogen is attributed to the Scottish physician Daniel Rutherford (1749-1819) in 1772, who called it “noxious air”, though he did not recognise it as an entirely different chemical substance or element. The name nitrogen was given to it in 1790 by the French chemist Jean-Antoine Chaptal (1756–1832), from the French nitre (potassium nitrate or saltpetre).

As air was now known to be a mixture of gases, mainly nitrogen and oxygen, air lost its position as an ‘element’. In 1783 Antoine Lavoisier (1743-1794), in co-operation with the mathematician Pierre-Simon de Laplace (1749-1827), reproduced Cavendish’s finding that water is created when “inflammable air” is burned. They synthesised water by burning jets of “inflammable air” and oxygen in a bell jar over mercury. This revealed that water also was not an element, but a compound of two gases. Lavoisier gave the “inflammable air” the much more suitable name of hydrogen (ὑδρο = hydro  meaning “water” and γενής genes meaning “creator”).

Lavoisier helped develop the first comprehensive list of elements (of which there were 29), and helped to reform chemical nomenclature. He predicted the existence of silicon (1787) and discovered that, although matter may change its form or shape, its mass always remains the same. His wife and laboratory assistant, Marie-Anne Paulze Lavoisier (1758-1836) became a renowned chemist in her own right.

 

 

 

 

The First Series of the Lunar Feature of the Month ran from September 2016 to December 2024.

There are 100 features illustrated by 140 lunar images.

 

To access the First Series Archive, click  here .