On April 26, the spacecraft will pass inside Saturn’s main rings for the first time.

C Ring
Saturn’s rings are made of ice and rock particles, ranging from fine dust to large boulders and moonlets.

The rings are named in order of discovery, from A to G. The C ring was the last of the main rings to be discovered, in 1850.

A faint D ring lies inside the C ring but is too transparent to be seen in this image.

B Ring
A bright, opaque ring about twice as wide as Earth. The B and A rings are separated by the dark band of the Cassini division.

Cassini Division
A 2,900-mile-wide gap caused by the gravity of the moon Mimas.

A Ring
The outermost ring typically seen in popular images of Saturn. Two small gaps near the edge of this ring are caused by the tiny moons Pan and Daphnis.

F Ring
A narrow, braided ring discovered by the Pioneer 11 spacecraft in 1979. The F ring lies between the orbits of Prometheus and Pandora, two small moons.

Relative size
of Earth

Ring-grazing orbits
Cassini has been orbiting just outside of Saturn’s F ring since November. The faint G and E rings are farther out and not shown here.

NASA/Jet Propulsion Laboratory

Ring World

An artist’s impression of Cassini flying inside Saturn’s C and D rings.

NASA/Jet Propulsion Laboratory/Erick Sturm

The Grand Finale

Cassini will complete its last ring-grazing orbit (gray line) on Saturday, then begin a series of 22 orbits that pass inside the rings (blue lines). The spacecraft will dive into Saturn’s atmosphere in September (orange line).

NASA/Jet Propulsion Laboratory/Erick Sturm

Shifting Orbit

An animation of Cassini moving from its current ring-grazing orbit (gray line) to an orbit that passes inside Saturn’s rings (blue line). The transition is scheduled for Saturday.

Surveying Saturn’s Moons

A short documentary about Cassini’s discoveries around Saturn.

The planet’s diffuse G and E rings appear purple in the image above, outside the brighter main rings.