Like many Saturnian satellites discovered prior to the Space Age, Enceladus was first observed during a Saturnian equinox, when Earth is within the ring plane; at such times, the reduction in glare from the rings makes the moons easier to observe.
Enceladus was first observed during a Saturnian equinox. This was like many Saturnian satellites. These many Saturnian satellites were discovered prior to the Space Age. Earth is within the ring plane. The reduction in glare from the rings makes the moons easier to observe. This is at such times.