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Ptolemaeus Region
© 2016 Klaus Brasch




Deslandres
© 2016 Klaus Brasch

© 2016 Klaus Brasch

Both of these Lunar photos were taken with the C-14 HD at f/11 and deep red filter and the ZWO ASI 120 MC camera in greyscale mode, stacked in Registax. The first image is of the Ptolemeus Region and the second is of Deslandres.

Klaus Brasch        







The following was retrieved from Wikipedia, the free encyclopedia, at en.wikipedia.org/wiki/Ptolemaeus_(lunar_crater) on April 20, 2016

Ptolemaeus (lunar crater)

"Ptolemaeus is an ancient lunar impact crater close to the center of the near side, named for Claudius Ptolemy, the Greco-Roman writer, mathematician, astronomer, geographer and astrologer.

To the south-southeast, Ptolemaeus is joined to the rim of the crater Alphonsus by a section of rugged, irregular terrain, and these form a prominent chain with Arzachel to the south. To the southeast is Albategnius and to the north is the smaller but well-defined Herschel.

The features of Ptolemaeus are highlighted when the Sun is at low angles during the first and last quarter. At full Moon the Sun is directly overhead and the crater contours become more difficult to discern.

The crater has a low, irregular outer rim that is heavily worn and impacted with multiple smaller craters. The rim has a discernibly polygonal shape, although overall it remains circular. The largest of the peaks along the rim, designated Ptolemaeus Gamma (γ), has an altitude of 2.9 km and is located along the northwest rim. The crater has no central peak, a lava-flooded floor, and lacks a ray system. Impact sites of this form are often classified as walled plains, due to their resemblance to the maria.

The somewhat dark-hued floor of Ptolemaeus is notable for several ghost craters, formed where lava has covered a pre-existing crater. These leave only a slight rise where the rim existed, and are difficult to detect except at low angles of sunlight. There are also multiple smaller craters across the floor surface, most notably Ammonius in the northeastern quadrant.

On either side of this crater are linear, irregular gashes in the lunar surface, forming valley-like features. These features are approximately parallel to each other and radiate from the direction of Mare Imbrium to the north-northwest."

The license terms of this written work from Wikipedia may be found at http://creativecommons.org/licenses/by-sa/3.0/











The following was retrieved from Wikipedia, the free encyclopedia, at en.wikipedia.org/wiki/Deslandres_(crater) on April 20, 2016

Deslandres (lunar crater)

"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. The name for this formation was suggested by Eugène M. Antoniadi in 1942, and was passed during the general assembly of the IAU in 1948.

According to one version, Luna 5 impacted lunar surface in this crater (31°S 8°W).

The first released images from the Lunar Reconnaissance Orbiter in 2009 were of the area in the southern part of this crater."

The license terms of this written work from Wikipedia may be found at http://creativecommons.org/licenses/by-sa/3.0/






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