Respuesta :

Tedygirls
when the moon is between the sun and the earth.
AL2006
-- the Earth is at perihelion  (around January 5)
and
-- the Moon is at perigee (once every 27.32 days)

and

either
-- the Moon is New (once every 29.53 days)
or
-- the Moon is Full (once every 29.53 days)