periselenium

periselenium (uncountable)

1. (astronomy) The point of a body's elliptical orbit about the moon's centre of mass where the distance between the body and the centre of mass is at its minimum.

• periselene

1. • 2004, Science and Technology Series, volume 108, American Astronautical Society, page 162:

     Hence, the Earth gravity allows the decrease of the particle energy from zero to a negative value and its capture by the moon to an elliptical orbit, e.g., with a periselenium of ~2,000 km and a high aposelenium of ~70,000h km.

• aposelenium