Naming of moons to as "Proserpina". More recently, especially in science-fictional contexts, the Moon has been called by the Latin name "Luna", presumably on the analogy of the Latin names of the planets, or by association with the adjectival form "lunar". In technical terminology, the word-stems "seleno-" (from Greek "selēnē" "moon") and "cynthi-" (from "Cynthia", an epithet of the goddess Artemis) are sometimes used to refer to the Moon, as in "selenography, selenology," and "pericynthion." The moons of Mars (Phobos and Deimos) were named by Asaph Hall in 1878, soon after he discovered them. They are named after the sons of the god
Phobos (moon) seen from Phobos, Mars would appear 6,400 times larger and 2,500 times brighter than the full Moon appears from Earth, taking up a quarter of the width of a celestial hemisphere. The Mars–Phobos Lagrangian L1 is above Stickney, which is unusually close to the surface. An observer situated on the Martian surface, in a position to observe Phobos, would see regular transits of Phobos across the Sun. Several of these transits have been photographed by the Mars Rover "Opportunity". During the transits, Phobos's shadow is cast on the surface of Mars; an event which has been photographed by several spacecraft.