Titan Ringlet and Bending Wave in Saturn's Rings

A dynamical interplay between Saturn's largest moon, Titan, and its rings is captured in this view from NASA's Cassini spacecraft.

At every location within Saturn's rings, particles orbit with a particular period, or rhythm. This image is focused on two separate and nearby locations in the rings where those rhythms are in synchrony with different aspects of Titan's 16-day orbit, creating signature effects that point from a distance back towards Titan.

The Titan Ringlet, embedded within the Colombo Gap at the center of this image, is slightly oval-shaped and always points its long axis towards Titan. The behavior and orientation of the ringlet are controlled by a gravitational resonance between Titan's 16-day orbit and the rate at which ring particles' oval-shaped paths rotate ("precess") around the planet. Because the particles' orbit precession is sensitively tied to Saturn's internal gravity structure, the radial location of the Titan Ringlet supplies scientists with the best available measurement of the outer layers of Saturn's interior.

Just inward of the gap is a very narrow feature that transitions from bright at the top of the image to dark at the bottom. This is a bending, or vertical, wave generated by a similar resonance with Titan, but this time it involves a synchronicity between the out-of-plane motion of Titan, which is on an inclined (tilted) orbit and similar motions of the ring particles with their own inclined orbits. In this image, taken near Saturn's 2009 equinox when sunlight hit the rings nearly edge-on, the vertical structure of the bending wave is obvious because of shadows giving it an unusual bright-to-dark appearance.

Also visible because of the shallow illumination angle is the vertical corrugation that crosses the entire C ring. This is the after-effect of a large impactor that is believed to have hit the inner Saturnian rings around the year 1983. Looking like a pattern of faint stripes, the corrugation is best seen on the right-hand side of the image, where other ring structure is sparse.

This view looks toward the sunlit side of the rings from about 9 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on September 20, 2009.

The view was obtained at a distance of approximately 288,000 miles (463,000 kilometers) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 13 degrees. Image scale is 1 mile (2 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Note: For more information, see Cassini Sees Saturn and Moons in Holiday Dress.

Prometheus and the Rings

Saturn's moons create art on the canvas of Saturn's rings with gravity as their tool. Here Prometheus is seen sculpting the F ring while Daphnis (too small to discern in this image) raises waves on the edges of the Keeler gap.

Prometheus (53 miles, or 86 kilometers across) is just above image center while Daphnis (5 miles, or 8 kilometers across), although too small to see in its location in the Keeler gap just to the right of center, can be located by the waves it creates on the edges of the gap. Prometheus and stars have been brightened by a factor of 2 relative to the rest of the image to enhance their visibility. There are 20 stars visible in this image.

This view looks toward the unilluminated side of the rings from about 53 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on August 25, 2013.

The view was acquired at a distance of approximately 1.2 million miles (1.9 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 111 degrees. Image scale is 7 miles (11 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Epimetheus and Daphnis

While the moon Epimetheus passes by, beyond the edge of Saturn's main rings, the tiny moon Daphnis carries on its orbit within the Keeler gap of the A ring. Although quite different in size, both moons create waves in the rings thanks to their gravitational influences.

Epimetheus (70 miles, or 113 kilometers across) is visible at the lower-right of the image, and Daphnis (5 miles, or 8 kilometers across) is barely visible at one pixel wide just below-right of the image center. A close inspection of the image also reveals the waves Daphnis creates on the edges of the Keeler gap.

This view looks toward the unilluminated side of the rings from about 2.6 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 28, 2013.

The view was acquired at a distance of approximately 808,000 miles (1.3 million kilometers) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 28 degrees. Image scale is 5 miles (8 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Pan and Waves in Saturn's A-Ring

The shepherd moon Pan orbits Saturn in the Encke gap while the A ring surrounding the gap displays wave features created by interactions between the ring particles and Saturnian moons.

Pan (17 miles, or 28 kilometers across) maintains the Encke gap through gravitational interactions with ring particles. The wave features in the A ring are generated through interactions between ring particles and moons such as Pan.

This view looks toward the sunlit side of the rings from about 34 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 11, 2013.

The view was obtained at a distance of approximately 240,000 miles (386,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 111 degrees. Image scale is 1 mile (2 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Daphnis in the Keeler Gap

The tiny wavemaker moon Daphnis is dwarfed by the very waves it creates on the edge of the Keeler gap. Daphnis (5 miles, or 8 kilometers across), a tiny dot in the Keeler gap, raises waves on the edges of that gap as it passes the ring material. Daphnis' gravitational encounters also maintain the gap, shepherding material back into the ring.

The two bright dots between the A and F ring are stars. For more about Daphnis, see PIA06238.

This view looks toward the unilluminated side of the rings from about 50 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on January 15, 2013.

The view was acquired at a distance of approximately 870,000 miles (1.4 million kilometers) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 99 degrees. Image scale is 5 miles (8 kilometers) per pixel.

Photo credit: NASA/JPL-Caltech/Space Science Institute

Daphnis and the Keeler Gap

Saturn's small moon Daphnis is caught in the act of raising waves on the edges of the Keeler gap, which is the thin dark band in the left half of the image. Waves like these allow scientists to locate small moons in gaps and measure their masses.

For more on Daphnis (5 miles, or 8 kilometers across) and the Keeler gap, see PIA11655 and PIA06238.

This view looks toward the sunlit side of the rings from about 13 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on August 14, 2012.

The view was obtained at a distance of approximately 483,000 miles (778,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 4 degrees. Image scale is 3 miles (4 kilometers) per pixel. The F ring has been brightened by a factor of 1.5 relative to the main rings to enhance visibility.

Photo credit: NASA/JPL-Caltech/Space Science Institute

A-Ring Structures

Several structures in Saturn's A ring are exposed near the Encke Gap in this Cassini image.

Structure is clearly visible in the ringlets that occupy the Encke Gap in the lower right of this image. A peculiar kink can be seen in one particularly bright ringlet at the bottom right. To view vertical structures in these kinky, discontinuous ringlets casting shadows during Saturn's August 2009 equinox, see PIA11676.

Nearly uniform striations in the A ring created by the gravitational effects of the moon Pan dominate the left of this image. Saturn is out of the frame to the right. Also visible are two waves -- darker banded structures -- to the left of the Encke gap. See PIA10501 to learn more about the waves present here.

This view looks toward the southern, unilluminated side of the rings from about 18 degrees below the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 3, 2010. The view was acquired at a distance of approximately 177,000 kilometers (110,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 60 degrees. Image scale is 700 meters (2,296 feet) per pixel.

Photo credit: NASA/JPL/Space Science Institute