Earthlight is a feature on Earth's Moon, a crater in the Hadley–Apennine region.
Astronauts David Scott and James Irwin drove past it on their Lunar Roving Vehicle in 1971, on the Apollo 15 mission, during EVA 2.
The crater is subdued and not obvious on the surface, and the astronauts did not stop to observe it.
During the drive towards Mons Hadley Delta, Jim Irwin said, "I can just barely see the western slope of Earthlight.
[1] Clarke was delighted to receive a three-dimensional map of the landing site signed and sent by the Apollo 15 crew, two decades after the novel was written.