What is the origin of perilune?

Perilune “the point in a lunar orbit that is nearest to the moon” is a compound of the combining form peri- “about, around, near” and the element -lune “moon.” Peri-, from Ancient Greek perí “about, around,” is a common fixture in words related to closeness, such as perimeter and periphery, and in perilune, it is combined with -lune on the pattern of perigee “the point in an orbit that is nearest to the earth” (using Ancient Greek gaîa or “earth”). Unlike perigee, perilune features a Latin-origin element, -lune (from Latin lūna) to mean “moon”; if this element were derived instead from Ancient Greek selḗnē “moon” to better match perigee, we would be saying something like “periselene” instead! Perilune was first recorded in English in the late 1950s.