Lunar Imagery in 2012

By Damian Peach.

This gallery displays Lunar Imagery obtained during 2012 (dates and times are in the file names.) Some of the text used below is from Wikipedia articles on the respective features.

 

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Grimaldi at sunrise. This ancient flooded impact basin is 174km in diameter and is located near the western edge of the lunar nearside. There are many interesting geological features in the area including a peculiar ridged region on the far side of the basin.


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Hevelius at sunrise. Laying near the western edge of the visible moon, this ancient flooded crater is 106km in diameter and its floor is covered in a network of fine rilles. The prominent crater above Hevelius is the smaller 58km Cavalerius.


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Archimedes nears sunset. One of the larger craters on the edge of the Mare Imbrium, Archimedes is 83km in diameter. It is almost filled to the top by ancient lava having buried the original central peak. Its floor is littered with many smaller impact craters and this view shows many long shadows cast across the lunar surface by the low sun. 356mm reflector. PGR Flea3. Selsey, UK.


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Longomontanus. One of the larger craters in the southern highlands of the Moon. It is 145km in diameter and much like Clavius the crater has been flooded by ancient lava leaving only the top of the central peak visible just right of centre. 356mm reflector. PGR Flea3. Selsey, UK.


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Clavius. One of the Moons most famous craters. It is 225km in diameter and peppered by impacts. Its floor is also flooded with ancient lava. As a result on the top of the original central peak is visible. The large craters Rutherfurd (top left) and Porter (bottom left) cut through the wall of this large crater. Clavius was formed more than 3 billion years ago when a large object hit the lunar surface. 356mm reflector. PGR Flea3. Selsey, UK.


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Aristarchus, Herodotus & Vallis Schroteri. Aristarchus is the brightest of the major lunar features and can be seen as a bright spot with the naked eye. The reason the crater appears so bright is due to its relatively young age of around 450 million years. 356mm reflector. PGR Flea3. Selsey, UK.


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Aliacensis & Werner. Aliacensis is a lunar impact crater that is located in the rugged southern highlands of the Moon. The Werner is located just to the north-northwest, and a narrow, rugged valley lies between the two comparably-sized formations. The rim of Aliacensis is generally circular, with an outward bulge on the eastern wall. The inner wall has some slight terracing particularly in the northeast. There is a small crater located across the southern rim. The interior floor is generally flat, with a low central peak slightly offset to the northwest of the mid-point.

Werner shows little appearance of wear, and is much younger and less eroded that the other large craters in the surroundings. The interior wall is terraced, and there is a noticeable rampart on the exterior. There are several low rises on the crater floor and a notable central peak. Rev. T. W. Webb noted two very bright spots along the sides of this crater, more visible in larger aperture telescopes. The Clementine Lunar Atlas displays a patch of high albedo surface along the northern inner wall. 356mm reflector. PGR Flea3. Selsey, UK.


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Vallis Alpes (latin for"Alpine Valley") is a spectacular lunar valley feature that bisects the Montes Alpes range. It extends 166 km from the Mare Imbrium basin, trending east-northeast to the edge of the Mare Frigoris. The valley is narrow at both ends and widens to a maximum width of about 10 km along the middle stretch.

The floor of the Vallis Alpes is a flat, lava-flooded surface that is bisected by a very narrow, cleft-like rille. (This cleft is a well known and challenging target for telescopic observation from the Earth.) The sides of the valley rise from the floor to the surrounding highland terrain, a blocky, irregular surface. The southern face of the valley is straighter than the northern side, which is slightly bowed and uneven. The more rugged edges of the valley lie at the narrow west-southwest end that cuts through the mountain range. Most likely this valley is a graben that was subsequently flooded with magma. This valley was discovered in 1727 by Francesco Bianchini. 356mm reflector. PGR Flea3. Selsey, UK.


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Tycho is a very prominent impact crater located in the southern lunar highlands, named after Tycho Brahe. The surface around Tycho is replete with craters of various differing radii, many overlapping still older craters. Some of the smaller craters are secondary craters formed from larger chunks of ejecta from Tycho.

Tycho is a relatively young crater, with an estimated age of 108 million years, as estimated from samples of the crater rays recovered during the Apollo 17 mission. The crater is sharply defined and free of the wear that affects older craters. The interior has a high albedo that is prominent when the sun is overhead, and the crater is surrounded by a distinctive ray system forming long spokes that reach as long as 1,500 kilometers. Sections of these rays can be observed even when Tycho is only illuminated by earthlight. 356mm reflector. PGR Flea3. Selsey, UK.


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Rimae Triesnecker. To the east of the Triesnecker crater is an extensive system of rilles extending over an area 200 kilometers across, running generally north-south. These were likely created by tectonic forces beneath the surface. Beyond, to the northeast, is the Rima Hyginus valley, with the Hyginus crater at the mid-point. 356mm reflector. PGR Flea3. Selsey, UK.


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Torricelli is a lunar crater in the eastern part of the Sinus Asperitatis, to the south of the Mare Tranquillitatis. The western rim of the crater is broken open and joined to a smaller crater to the west. The entire formation has a pear-shaped appearance. Torricelli lies in the northeastern part of a circular formation of rises in the lunar mare, possibly the remains of a crater formation buried by lava. 356mm reflector. PGR Flea3. Selsey, UK.


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Theophilus is a prominent impact crater that lies between Sinus Asperitatis in the north and Mare Nectaris to the southeast. It partially intrudes into the comparably-sized Cyrillus crater to the southwest. 

The Rev. T. W. Webb described this as "the deepest of all visible craters". The rim of Theophilus crater has a wide, terraced inner surface that shows indications of landslips. The exterior has a wide, wrinkled rampart that descends about 1.4 kilometers to the surrounding maria. The largest impact crater of significance on the wall is the small Theophilus B on the inside of the northwest rim. Most of the rays from this crater have been weathered away, although a few are still visible.

The floor of the crater is relatively flat, and it has a large, triple-peaked central crater that climbs to a height of about 2 kilometers above the floor. The western peak is designated Psi (ψ), the eastern Phi (φ), and the northern peak is Alpha (α) Theophilus. The western slopes of this ridge are wider and more irregular, whereas the peaks descend more sharply to the floor on the northern and western faces. The Apollo 16 mission collected several pieces of basalt that are believed to be ejecta from the formation of the Theophilus crater. 356mm reflector. PGR Flea3. Selsey, UK.


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Rima Sheepshanks. This extremely narrow sinuous rille runs for 200km across the Mare Frigoris and is a very challenging feature to observe. It is pitted my numerous tiny craterlets along its length. 356mm reflector. PGR Flea3. Selsey, UK.


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Rutherfurd is an impact crater located entirely within the southern rim of the much larger Clavius crater. Rutherfurd forms the larger member in an arcing chain of craters of decreasing size that curve across the floor of Clavius crater. The craters in this chain do not appear to be the same age, so this formation is most likely random in nature.

Rutherfurd is somewhat oval in shape, with the long axis oriented approximately in a north-south direction. The northern outer ramparts have a series of radiating ridges on the floor of Clavius crater. The rim is overlaying the inner wall of Clavius, and thus the rim of Rutherfurd is higher above the surface along the north and west sides. The floor is irregular in shape, and there is a central peak somewhat offset to the northeast. The ejecta pattern; oblong shape, and location of the central peak indicate the original impact may have been at a low angle from the southeast. 356mm reflector. PGR Flea3. Selsey, UK.


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Reinhold is a prominent impact crater that lies to the south-southwest of Copernicus crater, on the Mare Insularum. The interior walls are terraced and the irregular outer ramparts are visible against the flat surface of the mare. The interior floor of Reinhold is relatively featureless, with only a few low rises. Just to the northeast is a low, flooded crater designated 'Reinhold B'. 356mm reflector. PGR Flea3. Selsey, UK.


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Plato is the maria-surfaced remains of an impact crater. It is located on the northeastern shore of the Mare Imbrium, at the western extremity of the Montes Alpes mountainous range. The age of the Plato walled-plain is about 3 billion years; younger than the Mare Imbrium to the south. The rim is irregular with 2-km-tall jagged peaks that project prominent shadows across the crater floor when the sun is at a low angle. Sections of the inner wall display signs of past slumping, most notably a large triangular slide along the western side. The rim of Plato is circular, but from the Earth it appears oblong due to foreshortening.

The flat floor of Plato has a relatively low albedo, making it appear dark in comparison to the surrounding rugged terrain. The floor is free of significant impact craters and lacks a central peak. However there are a few small craterlets scattered across the floor. Plato has developed a reputation for various transient lunar phenomenon, including flashes of light, unusual color patterns, and areas of hazy visibility. These anomalies are likely a result of seeing conditions, combined with the effects of different illumination angles of the Sun. The astronomer Johannes Hevelius originally called this feature the 'Greater Black Lake'. 356mm reflector. PGR Flea3. Selsey, UK.


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Maurolycus is one of the more prominent lunar craters in the southern highland region of the Moon that is covered in overlapping crater impacts. It is joined at the southeast rim by the smaller Barocius crater.

The outer wall of Maurolycus are tall, wide, and terraced; most notably in the eastern part. To the southeast the rim is lower and the crater is joined to what has the appearance of an overlain crater rim. The crater 'Maurolycius F' lies across the northwest rim, and that part of the crater floor is more rugged than the remainder. The other sections of the floor are relatively level, with a complex of central peaks and a pair of craterlets. The small crater 'Maurolycus A' is biting into the southern part of the rim. 356mm reflector. PGR Flea3. Selsey, UK.


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Manilius is a lunar impact crater on the northeast edge of Mare Vaporum. It has a well-defined rim with a sloping inner surface that run directly down to the ring-shaped mound of scree along the base, and a small outer rampart. The small crater interior has a higher albedo than the surroundings, and it appears bright when the sun is overhead. Within the crater is a central peak formation near the mid-point. Manilius also possesses a ray system that extends for a distance of over 300 kilometers. 356mm reflector. PGR Flea3. Selsey, UK.


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Heraclitus is a complex lunar crater that lies in the rugged southern highlands of the Moon. Licetus crater forms the northern end of the formation. Just to the east is Cuvier crater, and due south is Lilius crater.

The entire formation is heavily worn, with features smoothed down by a long history of impacts. Heraclitus is a complex formation composed of three sections divided by a triple-armed interior ridge. Of the three sections, the most eroded and irregular is at the eastern end where the outer rim forms a low ridge that joins to Cuvier crater.

The circular southwest end is the most intact section, forming the circular satellite crater 'Heraclitus D', which is attached to the other two sections along the northeast rim. There are a pair of ghost-crater rims on the floor, and a low ridge in the southwest. Just to the west of Heraclitus is the small satellite crater 'Heraclitus K', to the south of which is a pair of larger overlapping craters, 'Lilius E' and Lilius D'. 356mm reflector. PGR Flea3. Selsey, UK.


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Rima Hadley is a famous sinuous rille which lies close to the Montes Apenninus and is most famous for Apollo 15 landing there duing the 1970s. It is thought to be the remains of a collapsed lava tube. It is approximately 1.5km wide, and between 0.3 - 0.7km deep. Nearby Mons Hadley towers more than 5km above the lunar surface. It was very close to the northern "curve" of the rille (near the top in these images) that Apollo 15 landed on July 30th, 1971. 356mm reflector. PGR Flea3. Selsey, UK.


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Eratosthenes is a relatively deep lunar impact crater that lies on the boundary between the Mare Imbrium and Sinus Aestuum maria regions. The crater has a well-defined circular rim, terraced inner wall, central mountain peaks, an irregular floor, and an outer rampart of ejecta. It lacks a ray system of its own, but is overlaid by rays from the Copernicus crater to the south-west. The Eratosthenian period in the lunar geologic timescale is named after this crater. The crater is believed to have been formed about 3.2 billion years ago, defining the start of this time period.

At low sun-angles this crater is prominent due to the shadow cast by the rim. When the sun is directly overhead, however, Eratosthenes visually blends into the surroundings, and it becomes more difficult for an observer to locate it. The rays from the Copernicus crater lie across this area, and the higher albedo of these rays serves as a form of camouflage.

In 1924, William H. Pickering noted dark patches in the crater that varied in a regular manner over each lunar day. He put forward the speculative idea that these patches appeared to migrate across the surface, suggestive of herds of small life forms. The idea received a degree of attention primarily due to Pickering's reputation. 356mm reflector. PGR Flea3. Selsey, UK.


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Deslandres & Walter. Deslandres is the heavily worn and distorted remains of a lunar impact crater. It is located to the southeast of the Mare Nubium, in the rugged southern highlands of the Moon. In dimension it is the second-largest crater formation on the visible Moon, being beaten only by the 303-kilometer-diameter walled plain Bailly. The northern and eastern parts of the floor display a relatively level surface, but it is pock-marked with numerous craters. There is a small region of mare material, due to basaltic lava, along the eastern interior floor.

The crater Walther is attached to the remnant of the eastern rim, and Ball intrudes into the southwestern rim. The crater remnant Lexell has broken across the southeastern rim, forming a "harbor" in the crater floor due to the wide gap in its northern rim. The irregular crater Regiomontanus is attached to the northeast rim of Deslandres. The crater Hell lies entirely within the western rim.

The satellite crater Hell Q lies at the center of a patch of higher albedo surface located in the eastern half of Deslandres. Around the time of the full moon this feature is one of the brightest spots on the lunar surface. The light hue indicates a relatively youthful feature in lunar geological terms. This patch is sometimes referred to as "Cassini's bright spot", as it was first mapped by Cassini in 1672 at the Paris Observatory.

This feature is so heavily eroded and degraded by overlapping impacts that it was not actually recognized as a crater formation until the 20th century. 356mm reflector. PGR Flea3. Selsey, UK.


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Copernicus is a prominent impact crater located on the eastern Oceanus Procellarum.  The crater Copernicus is estimated to be about 800 million years old, the time marking the start of the Copernican era in the Lunar geologic timescale. Due to its relative youth, the crater has received very little erosion and it remains sharp and well-defined.

The circular rim has a discernable hexagonal form, with a terraced inner wall and a 30-km wide, sloping rampart that descends nearly a kilometer to the surrounding maria. There are three distinct terraces visible, and arc-shaped landslides due to slumping of the inner wall as the crater debris subsided.

Most likely due to its recent formation, the crater floor has not been flooded by lava. The terrain along the bottom is hilly in the southern half while the north is relatively smooth. The central peaks consist of three isolated mountainous rises climbing as high as 1.2 km above the floor. These peaks are separated from each other by valleys, and they form a rough line along an east-west axis. Infrared observations of these peaks during the 1980s determined that they were primarily composed of the mafic form of Olivine.

The crater rays from Copernicus spread as far as 800 kilometers across the surrounding maria, overlaying rays from the Aristarchus and Kepler craters. The rays are less distinct than the long, linear rays about Tycho crater, instead forming a nebulous pattern with plumy markings. In multiple locations the rays lay at glancing angles, instead of forming a true radial dispersal. An extensive pattern of smaller secondary craters can also be observed surrounding Copernicus, a detail that was depicted in a map by Giovanni Cassini in 1680. Some of these secondary craters form sinuous chains in the ejecta. 356mm reflector. PGR Flea3. Selsey, UK.


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Cassini is an impact crater that is located at the eastern end of Mare Imbrium. The floor of the crater is flooded, and is likely as old as the surrounding maria. The surface is peppered with a multitude of impacts, including a pair of significant craters contained entirely within the rim. Cassini A is the larger of these two, and it lies just north-east of the crater center. A hilly ridge area runs from this inner crater toward the south-east. Near the south-west rim of Cassini is the smaller crater Cassini B. 356mm reflector. PGR Flea3. Selsey, UK.


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C. Mayer is a lunar impact crater that is located at the northern edge of the Mare Frigoris, due north of the prominent crater Aristoteles and is 38km in diameter. 356mm reflector. PGR Flea3. Selsey, UK.


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Bullialdus is an impact crater located in the western part of the Mare Imbrium. The relatively isolated location of this crater serves to highlight its well-formed shape. Bullialdus has a high outer rim that is circular but observers have noted a slightly polygonal appearance. The inner walls are terraced and contain many signs of landslips. The outer ramparts are covered in a wide ejecta blanket that highlights a radial pattern of low ridges and valleys. 356mm reflector. PGR Flea3. Selsey, UK.


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Autolycus.

This prominent small lunar impact crater is 39km across and lies just to the south of Aristillus. It has a faint impact ray system extending around 400km from the crater, some material of which crosses the floor of the nearby Archimedes crater. 356mm reflector. PGR Flea3. Selsey, UK.


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Arzachel.

Another well known crater forming a famous trio with the larger Alphonsus and Ptolemaeus craters to the North. Arzachel is the youngest of the three, and is 96km in diameter. A variety of interesting features are associated with this crater such as the faint rille system across the crater floor. 356mm reflector. PGR Flea3. Selsey, UK.


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Aristoteles.

Aristoteles is an impact crater on the southern edge of the Mare Frigoris. It is 87km across and forms a prominent pairing with the nearby Eudoxus crater to the south (37km in diameter.) 356mm reflector. PGR Flea3. Selsey, UK.


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Aristillus.

This prominent 55km wide crater lies to the south west of Archimedes. This crater has a bright impact ray system extending for more than 600km. Note the faint remains of a ghost crater off the top left almost completely buried by ancient lava flows. 356mm reflector. PGR Flea3. Selsey, UK.


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Alphonsus.

Alphonsus (119km) is a prominent crater near the centre of the visible Moon. Alphonsus was the impact site of the Ranger 9 probe in March 1965. The crater contains a complex system of rilles as well as dark halo craters. 356mm reflector. PGR Flea3. Selsey, UK.


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Abulfeda

This crater located in the central highlands of the Moon is 65km in diameter. Note the crater chain stretching from Abulfeda out of the field. This chain stretches more than 200km in length across the Rupes Altai. 356mm reflector. PGR Flea3. Selsey, UK.


 

All images copyright Damian Peach. No images used on this page may be used. amended, or distributed without the consent of the author.