Left.  Ridge Section 154; Right: Cropped 1200 dpi USGS color chart of Section 154                                            
Larger expanded region version of color chart above
Lunascan Composite of Sections 144,145,154,155
Apollo Basin Color Quad of Sections 144,145,154,155
  USGS Charts 3040S-200220
LAC 121 WAC (Original pdf)
Lunascan Composite of LAC/WAC_121-122-134-135.htm

The Apollo Basin, Ridge section 154, is an enormous impact crater (537 km wide) located in the southern hemisphere on the far side of the Moon. To see the full range of this basin one can view the composites and quad linked above, but all four sections 144, 145, 154, and 155 need to be examined. This formation dwarfs the large crater Oppehheimer that is located next to the western rim. The crater Barringer lies across the northern wall. To the southeast is the crater Anders and Kleymenov is just to the east of the rim. All of these craters are out of frame in this section. Apollo is a double-ringed walled plain whose inner ring is roughly half the diameter of the outer wall. Both the outer wall and the interior have been heavily worn and eroded by subsequent impacts, so that significant parts of the outer and inner walls now consist of irregular and incised sections of mountainous arcs. The interior floor is covered in a multitude of craters of various sizes. Several of the more notable craters have received names. The IAU used the eponyms of people associated with the Apollo program when designating some of these formations. Notable in this section are the craters Chafee, Borman, and Grissom.  Sections of Apollo's interior have been resurfaced with lava, leaving patches of the floor with a lower albedo than the surroundings. There is a large patch of this lunar mare in the middle part of the inner ring, which contains some ray system markings. A long stretch of the mare lies along the southern part of the crater. There is also a smaller section near the western rim. (Credit: Most of the information used in the section feature descriptions was obtained from wikipedia.com. Section 154 and this directory was created by Fran Ridge and Ned Haskin of The Lunascan Project).