Lunar Orbiter imagery of the Apollo landing sites is presented in the discussion of each of those missions. Here, we illustrate the landing sites that were the primary alternatives for the Apollo 15, 16, and 17 missions.
Lunar Nearside Locator MapMarius Hills
The Marius Hills in Oceanus Procellarum were considered the primary alternative to the Apollo 15 landing site at Hadley Rille.
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The Marius Hills are a group of low, volcanic domes. This type of volcanic structure is rare on the Moon. This oblique image clearly illustrates the relief on these domes. In addition, Marius Crater is visible at the upper right, and several wrinkle ridges are also visible. This region was considered as a potential Apollo landing site in the hope that studying the domes would contribute to our understanding of the volcanic evolution of the Moon. (Lunar Orbiter image II-213M.) |
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This overhead image, about 200 kilometers across, illustrates the extent of the Marius Hills. Several rilles (volcanic channels) are also visible, including a prominent one in the lower left of the image. (Lunar Orbiter image IV-157H2.) |
Alphonsus
Alphonsus crater was one of the primary alternatives considered for both the Apollo 16 and the Apollo 17 missions.
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The 119-kilometer-diameter Alphonsus Crater is at the center of this image, which also shows other features in the region east of Mare Nubium. At the upper left of the image is the Davy chain of craters, which was also given some consideration as a possible Apollo landing site. At the time, it was uncertain whether the Davy chain was a chain of secondary craters from some other, large impact structure (although the source crater is not obvious) or a chain of volcanic features. In the aftermath of the Comet Shoemaker-Levy 9 comet chain impacts with Jupiter in July 1994, it has been suggested that the Davy crater chain might be the result of a similar comet chain striking the Moon. (Lunar Orbiter image IV-108H2. Apollo 16 view of Davy crater chain.) |
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This image shows a close-up of the western portion of Alphonsus. The prospective landing site was in the dark patch near the western rim of the crater, near the center of the image. (Lunar Orbiter image V-118M.) |
Gassendi
Gassendi Crater, on the northern edge of Mare Humorum, was one of two primary alternatives to the Apollo 17 landing site at Taurus-Littrow.
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This image shows most of the 110-kilometer-diameter crater, whose floor is heavily fractured. The candidate landing site was south of the westernmost of Gassendi's central peaks. (Lunar Orbiter image V-178M.) |