Enceladus

Enceladus revolves around Saturn inside the E Ring. The satellite's bright
surface shows evidence of extensive resurfacing over time. Enceladus's
surface is so bright that it reflects almost 100 percent of the sunlight
that falls on it. By comparison, Earth's Moon reflects about 11 percent of
the sunlight that falls on it. The orbital position of Enceladus coincides
with the maximum thickness position of the E Ring, which had led
scientists to hypothesize that this satellite supplies material to the E
Ring.