Luna Notebook


https://eapod.org/aristoteles-eudoxus-craters-ron-giddy/ 

Click the link above to visit EAPOD.

With this image I was fortunate enough to be nominated for the European Astronomy Picture of the Day for 14 April 2021.

Aristoteles and Eudoxus craters are located on the Southern edge of the Luna Mare Frigoris - The Sea of Cold, which in terms of Mare descriptive Selenography is somewhat vaguely defined. Aristoteles lies east of the Montes Alpes and to the north of the Montes Caucasus which are at the foot of the image. It is an impact crater of approximately 87kms in diameter with a depth of 3700.0m. Its relatively shallow depth for a crater of such diameter may indicate post impact lava flooding. Unlike most examples of complex craters the absence of any high central mountain could be an indication that such an event did occur leaving only the tops of the impactor peaks visible. The almost complete collapse of the crater South-Western wall is sharply seen in this image along with well-defined terraces to the East bordering the earlier formed Mitchell crater. The South Wall of Aristoteles has also been “pushed in” by ejecta from the impactor that later produced Eudoxus crater.

Eudoxus crater is 67km in diameter and around 3.4km in depth, as with its neighbour it lacks a central peak and contains only a group of low hills scattered about the central area. The terraced structure of the walls is clearly visible.

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Sinus Iridum – The Bay of Rainbows. In this image clearly showing its classical Jewelled Handle, comprising an illusionary setting for 5 gemstones, only visible for a few short hours each month when the terminator passes over the basin.  The low sunlight illuminates the Jura mountains with a Clair-Obscur effect at 2 days after first quarter setting the valleys in deep shadow while highlighting the prominent peaks creating the visual effect of a Jewelled Handle. It is a highly prominent and imposing feature which stands out against a background of darkness which is difficult to image correctly while retaining the low Dorsa wrinkled wave like features within the bay that also come to prominence at this time.                                                                                                       

 Another hugely important and stand out feature of this image is the “Moon Maiden” first brought to prominence by the Italian astronomer Giovanni Cassini in a drawing published in 1679. “She” can be seen in the structure of the Promontorium Heraclides overlooking the peaceful bay. (to best view the Maiden, rotate the image 90 degrees counterclockwise).                                                                                

Other standout features are the Promontorium Laplace, the small crater Laplace A at the entrance to the bay and the crater Bianchini in deep shadow on the crest line of the Montes Jura. To the right of the image are the craters Helicon and Le Verrier.

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Plato crater and the surrounding area is a popular target for visual observers and imagers alike. It lies on the north-eastern shore of the Mare Imbrium. Its 101 km diameter lava filled floor is sombre in appearance and contains only a few minor impact craters. To the lower part of the image the scattered mountains are collectively known as the Montes Teneriffe. To the North is the Mare Frigoris- The Sea of Cold.


Located at the Northern end at the foot of the Apennine mountain range is the site of the Apollo 15 landing. The Apennine Escarpment named after the Italian Mountains of the same name is the highest point on the Moon at 5,400 m. Just to the North of the almost horizontal section of the Hadley rille seen in the image enlargement was the set down point for the landing. The average width of the rille is 1.2 kms and a total length of 130 kms and is thought to have been created by a Lava flow. It is one of the most defined sinus rilles visible.

6-19-2021 TSS Astrophotography Photo of the Day.

 "Apennine Mountains".

Todays TSS APOD comes from member RonGiddy (Ron).

Captured with stunning detail Rons image is well deserving!

Congratulations Ron on having your image selected as todays TSS APOD!jpg


Panorama.

This image is a full panoramic view of the Montes Apenninus and surrounding Lunarscape, in short “The Full Monty”. This area of the Luna surface is found at the South Eastern side of the Mare Imbrium and contains several regularly imaged features which allow the observer to compare this detailed high-definition coloured panorama with the many available. From the crater Eratosthenes in the South to the Promontorium Fresnel at the Northern end, the range covers a length of around 600 km. It contains some of the highest Luna mountains on record with heights ranging from 3.000 m to 5.500 m. The site for the Apollo 15 landing on the valley floor encompassed by the Mons Hadley and Mons Hadley Delta, skirted by the twisting Hadley Rille is clearly visible in the image at the Northern end of the range. There are interesting Hypotheses in existence concerning the creation of the Rille which is one of the most defined on the Luna surface and make for interesting reading for those with an interest in Selenology.  

Craters.

Archimedes is the largest of the visible craters at 81 km diameter. The floor is Lava filled with no central peak and the rim is unbreeched suggesting the Lava flooding source was from within the crater. The Mountainous crater marked area to the South is named Montes Archimedes. To the North Eastern section of the image lie the craters Aristillus and the smaller Autolycus. The impact ejecta of these craters is clearly discernible against the surrounding smoother surface of the Mare. Of interest to the north of Aristillus is seen the rim of a ghost crater almost totally submerged by the lava flows of the Mare Imbrium. Finally, to the west of the Montes Archimedes is the little-known crater grouping of Beer with is small crater chain clearly seen. As with all purposeful comment this area should not be confused with Beer crates or the surround Mare the Mare Inebriate.


Endymion, Atlas and Hercules craters are the featured objects in this image with the Mare Humboldtianum seen clearly on the Luna limb. Occasionally due to Luna Libration this small Mare is hidden from Earth’s view, the Libration will also foreshorten the view of Endymion which is not the case in this image.

Endymion is a flat lava filled crater with a diameter off around 125km. The crater floor has only a few small craterlet impacts visible, the string of three to the left of the crater being the most visible.

Atlas crater is equally as prominent as Endymion but at 87km diameter significantly smaller and at 2km depth much shallower. Floor fracturing, due to volcanism triggered by the impact event is clearly visible as are 2 darker pyroclastic spots. The centre is comprised of a relatively small cluster of hills, more evidence of probable after impact volcanic activity with lava welling up through the thin Luna crust.

Hercules to the left of Atlas is the third crater of this classic grouping. It is the smallest in diameter at 69km but also the deepest at 3.2km. The crater Hercules G is situated in the main floor. It has a depth of 1.3km is 13km across and a classic example of a “Bowl crater” several which can be observed in this image.

The observable area that surrounds the named craters has several small lava filled “Lacus” or “Lakes” three of which are named Mortis, Temporis and Somniorum (Dead, Time, and Dreams). Another of the often-missed points of interest in this area, outshone by the larger craters are the number of “ghost” and partially lava filled craters visible.

Clavius (just a stone’s throw in Luna terms from Tycho) in which October 2020 NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) detected the presents of H2O  Don’t get excited, the Sahara Desert contains more than 100 times the amount detected in Clavius. 

Tycho Crater visible 1st quarter + 1 day

Tycho Crater is one of the most prominent craters on the moon. It appears as a bright spot in the southern highlands with rays of bright material that stretch across much of the nearside. Its prominence is not due to its size: at 85 km in diameter, it is just one among thousands of this size or larger. What really makes Tycho stand out is its relative youth. It formed recently enough that its beautiful rays, material ejected during the impact event, are still visible as bright streaks.

It only around 108 Million years old.


This Image is an old one from my collection and is in my opinion one of the Classic Lunarscapes available to imagers.

On the Western edge of the Mare Nectaris are the craters of Theophilus and Cyrillus with their imposing central peaks taking centre stage.  Catherina and its numerous secondary impact craters and collapsed walls make up this remarkable trio. On the slope of Theophilus is the crater Madler seen with its damaged wall and central crest line. Further to the East  lies the ghost crater Daguerre which in this image is well defined.


Aristarchus crater is located on the aptly named Aristarchus Plateau or “Pyroclastic Aristarchus” in the Oceanus Procellarum- The Ocean of Storms. This General longshot overview of the 40 km diameter subject is the preferred option, as the close-up of the crater itself is particularly challenging due to the luminance of the crater. It is very easily overexposed. Aristarchus itself is one of, if not the brightest objects visible on the Luna near side to Earth, in fact it is easily seen with the naked eye and visible during “Earthshine”. It is located on the similarly named Plateau which itself has a different texture to the surrounding areas, is distinctive by its reddish tones is a 2 km high escarpment at its highest point and is a 200 km diamond shape. Another interesting feature of the crater itself are the walls that contain “bands” similar to spokes on a wheel.

The Neighbouring Crater is Herodotus, unlike its famous friend has a near flat lava filled floor. In some quarters this impact is attributed to causing the volcanic depression which in turn created the aptly named feature “The Cobras Head pit” that caused the massive outpouring of lava that created the longest rille valley on the Moon the “Vallis Schröteri” which is 185 km in length and 10km at its widest point.

The impact ejecta rays and the excavated “White rock” which make this Luna area so appealing are clearly visible in this image. The area also has a history of “High transient Luna Phenomenon”.


total luna eclipes.mp4