Final answer:
The term 'Earthrise' refers to the phenomenon observed by the Apollo astronauts while orbiting the Moon, where Earth is seen rising over the Moon's horizon from their vantage point. The term remains accurate despite the Moon being tidally locked to Earth, because the sight was witnessed while the astronauts were in lunar orbit. The Apollo missions provided many historic photographs, such as Earthrise and the 'Blue Marble'.
Step-by-step explanation:
The phrase 'Earth rising on the Moon' might seem problematic at first because from the surface of the Moon, Earth doesn't rise or set in the same way that the Moon or Sun does on Earth due to the Moon's synchronous rotation; it is tidally locked and shows only one face to the Earth.
However, the term 'Earthrise' is indeed used to describe the event witnessed by the Apollo astronauts who orbited the Moon. As they came around the far side of the Moon, which can't be seen from Earth, they saw the Earth rising over the lunar horizon. This is a momentous and historic visual captured by the Apollo missions such as Apollo 8, the first time humans saw Earthrise with their own eyes. The Apollo astronauts provided us with some of the most iconic images in space exploration history like the 'Blue Marble' and footprints that may last for millions of years due to the Moon's lack of atmosphere and geological activity, as seen in the photo of Buzz Aldrin's moonwalk during Apollo 11.