At the end of the mission, Alan Shepard became the only person to play golf on another world by hitting two golf balls in lunar gravity using a six-iron head he had had modified to mate to the lunar sample pickup stick tool (you could change out tools on the end). The spacesuit was so bulky that he could only swing with one hand and he duffed the first shot but hit the second one clean and said that even though it was probably a 35 yard shot on Earth, it went about 200 yards on the Moon. So there are two golf balls on the moon. Alan never told anyone the brand of those golf balls either.
Apollo 15
The landing site chosen for Apollo 15 was on the eastern margin of the Imbrium Basin in the region known as Palus Putredinis. There were two main objectives for this landing site. First, the rim of the Imbrium Basin could be sampled along the Appenine Mountains. It was expected that this would provide material from deeper in the lunar crust than was sampled in the Fra Mauro Formation by Apollo 14. Second, this site provided an opportunity to explore Hadley Rille, a photogenic channel in the mare surface that was probably formed by volcanic processes.
Apollo 15 was the first of the so-called J missions, which considerably expanded the capabilities for doing science on and near the Moon. For the first time, three 7-hour-long EVAs would be performed, and a lunar rover would significantly extend the distance a crew could travel over the lunar surface. In addition, the restriction on landing near the equator was lifted. Finally, a sophisticated suite of science experiments was also carried in the service module and used to map the Moon from orbit.
Apollo 16
The Apollo 16 landing site was selected to obtain samples of two highland geologic units, the Descartes Formation and the Cayley Formation, which are widespread on the lunar nearside. Prior to the mission, it was thought that both were of volcanic origin, but the returned samples demonstrated that this is incorrect. Three of the first four Apollo Moon landings were in mare regions and the fourth was in ejecta from the Imbrium impact. When selecting the Apollo 16 landing site, the highest priority was given to landing at a site in the lunar highlands, which occupy more than five times the surface area occupied by ‘Mare’ units.
The Descartes site was certified as safe for landing on the basis of Apollo 14 orbital photography. The specific landing site was selected between two fresh, young impact craters, North Ray Crater (1000 meters in diameter) and South Ray Crater (680 meters in diameter). These craters provided natural drill holes through the regolith at the site, exposing samples of the underlying bedrock in ejecta fragments for sampling by the Apollo 16 crew.
Apollo 17-Final Mission
Because Apollo 17 was the last lunar landing of the program, all of the high-priority candidate landing sites were given consideration again. However, many were eliminated from consideration for either scientific or operational reasons. A landing near the central peaks of Copernicus crater had long been considered, but was now regarded as of lower priority, both because some Apollo 12 samples may have provided an age for this impact event and because three landings had already occurred in the vicinity of Mare Imbrium. A landing in the southern highlands near Tycho crater was rejected because of concerns about rough terrain and mission safety.
A landing on the lunar farside in Tsiolkovsky crater was considered, but rejected because of operational difficulties and the added expense of providing the communications satellites that would be necessary to maintain radio contact between the landing site and ground controllers. A highland site southwest of Mare Crisium was considered, but was rejected because this region of the Moon was easily accessible to spacecraft launched by the Soviet Union. In fact, the Luna 20 spacecraft landed in this region in February 1972, just a week after the Apollo 17 site selection was made, and returned 30 grams of samples to Earth for analysis.
Old Highland Material
The first priority was obtaining samples of old highlands material (older than the Imbrium impact) from as large a distance as possible from the Imbrium basin. All three of the final candidate sites were between 800 and 1000 kilometers from the Imbrium basin.
Young Volcanic Material
The second objective was investigating the possible existence of young (less than 3 billion year old) volcanic activity. This was considered important both for understanding the thermal evolution of the Moon and also because interpretations of orbital photography suggested that young volcanism might have been explosive in nature and hence associated with a high abundance of volatile materials such as water.
Orbital Science
There were two competing objectives for obtaining orbital science coverage on the Apollo 17 mission. First, there was a desire to have orbital ground tracks that had minimal overlap with those of Apollo 15 and 16, so that the maximum amount of new information could be obtained. On the other hand, because Apollo 17 carried several new instruments, overlapping ground tracks with earlier missions would allow data from the new and old instruments to be compared over common areas.
So There You Have It
Well I managed to get hours of entertainment out of a single moon image. Hope you enjoyed it and did a little exploring on your own!
Bill the Sky Guy
December 6th, 2020
