NASA/JPL-Caltech/Space Science Institute
Saturn has an extensive ring system that extends out to 282,000km away from the planet, or about three quarters of the distance between the Earth and the Moon. Within this structure there are a dozen or so significant gaps, one of which is the Keeler Gap located near the outer edge of the planet's main rings. The tiny moon Daphnis has cleared this gap, which measures just 42km across.
One of the main benefits of having an orbiting spacecraft in a planetary system is multiple opportunities to image fine features—such as the 8km-wide moon Daphnis grazing through this narrow gap. And on Monday, NASA's Cassini spacecraft captured an amazing view of this interaction as Daphnis grazed Saturn's rings.
from Cassini spots a small moon surfing through Saturn’s rings