Apollo 10 in the context of Apollo 11

Apollonius is a lunar impact crater located near the eastern limb of the Moon. It lies in the region of uplands to the west of Mare Undarum and northeast of the Sinus Successus on the Mare Fecunditatis. It was named after Greek mathematician Apollonius of Perga. It is southwest of the crater Firmicus, and north of Condon.

The outer rim of Apollonius is somewhat worn and is overlain by a pair of small craters (including Apollonius E) across the western wall. The nearly flat interior floor has a low albedo and has been covered by lava. It lacks a central peak or notable small craters across the bottom.

Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated.

As part of the Apollo program by NASA, 24 astronauts flew nine missions to the Moon between December 1968 and December 1972. During six successful two-man landing missions, twelve men walked on the lunar surface, six of whom drove Lunar Roving Vehicles as part of the last three missions. Three men have been to the Moon twice, one orbited once and took a circumlunar trajectory the second time, while the other two landed once apiece. Apart from these 24 men, no human being has gone beyond low Earth orbit. As of December 2025, five of the 24 remain alive. A number of non-human animals have circled or orbited it, including two tortoises, several turtles, and five mice.

Apollo missions 8 and 10–17 were the nine crewed missions to the Moon. Apollo 4–6 and AS-201 and AS-202 were uncrewed, while AS-203 is considered a test flight. The Apollo program included three other crewed missions: Apollo 1 (AS-204) did not launch and its crew died in a ground-based capsule fire, while Apollo 7 and Apollo 9 were low Earth orbit missions that tested spacecraft components and docking maneuvers. Apollo missions 18, 19, and 20 were canceled. Twelve astronauts later flew unused Apollo command modules in the Apollo Applications Program's Skylab and Apollo–Soyuz Test Project. Of the 24 astronauts who flew to the Moon, two went on to command a Skylab mission, one commanded Apollo–Soyuz, one flew as commander for Approach and Landing Tests of the Space Shuttle, and two commanded orbital Space Shuttle missions.

Thomas Patten Stafford (September 17, 1930 – March 18, 2024) was an American Air Force officer, test pilot, and NASA astronaut, and one of 24 astronauts who flew to the Moon. He also served as Chief of the Astronaut Office from 1969 to 1971.

After graduating from the United States Naval Academy, Stafford was commissioned in the United States Air Force, flying the F-86 Sabre before becoming a test pilot. He was selected to become an astronaut in 1962, and flew aboard Gemini 6A in 1965 and Gemini 9A in 1966. In 1969, he commanded Apollo 10, the second crewed mission to orbit the Moon. Here, he and Gene Cernan became the first to fly an Apollo Lunar Module in lunar orbit, descending to an altitude of nine miles (fourteen kilometres).

Eugene Andrew Cernan (/ˈsɜːrnən/; March 14, 1934 – January 16, 2017) was an American astronaut, naval aviator, electrical engineer, aeronautical engineer, and fighter pilot.

Cernan traveled into space three times and to the Moon twice: as pilot of Gemini 9A in June 1966, as lunar module pilot of Apollo 10 in May 1969, and as commander of Apollo 17 in December 1972, the final Apollo lunar landing. He was also a backup crew member of Gemini 12, Apollo 7, and Apollo 14. During the Apollo 17 mission, he became the 11th person to walk on the Moon as well as the astronaut with the longest time spent walking on the Moon; he is also the last person to walk on the Moon.

Dubyago is a lunar impact crater that lies in the eastern limb of the Moon. It was named after Russian astronomers Dmitry Dubyago and Alexander Dubyago. It appears significantly foreshortened when viewed from the Earth. It lies along the southern shore of the Mare Undarum, to the southeast of the crater Firmicus.

This crater has a somewhat worn outer rim which dips down to a low point along the northern rim, and has its maximum altitude along the eastern side. The most notable aspect of this crater, however, is the dark hue of the interior floor which matches the albedo of the lunar mare to the northwest. This darker shading makes the crater stand out somewhat from its surroundings.

Maclaurin is a lunar impact crater that is located in the eastern part of the Moon's near side. It lies just to the southeast of the small Mare Spumans, and to the northeast of the prominent crater Langrenus. To the east-southeast is Gilbert.

The rim of this crater is perhaps unusual for the number of lesser craters attached to the exterior. Along the northern rim are the lava-flooded Maclaurin O and Maclaurin K. There are also satellite craters along the northeastern, eastern, and southern walls. The only open stretches of rim are along the western side, and a brief stretch to the southeast. The three craters along the southern rim, which include Maclaurin A and Maclaurin N, have intruded into the formation sufficiently to compress and slightly flatten that end of the crater. But overall it retains a generally circular form.