Pan in the Encke Gap

Saturn's tiny moon Pan orbits in the middle of the Encke Gap of the planet's A ring in this image from the Cassini spacecraft.

Pan (17 miles, or 28 kilometers across) is visible as a bright dot in the gap near the center of this view. See PIA12604 to see Pan casting a long shadow around the time of Saturn's August 2009 equinox.

The wide Roche Division separates the A ring from the thin F ring in the lower left quarter of the view. This view looks toward the southern, unilluminated side of the rings from about 20 degrees below the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 25, 2012. The view was obtained at a distance of approximately 1.2 million miles (2 million kilometers) from Pan. Image scale is 7 miles (12 kilometers) per pixel.

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

Promethean Shadow Before Equinox

Saturn's moon Prometheus casts a long shadow across the A ring in the middle-right side of this Cassini spacecraft image taken shortly before the planet's August 2009 equinox.

Prometheus (86 kilometers, or 53 miles across) orbits in the Roche Division between the thin F ring and the A ring. The novel illumination geometry created around the time of Saturn's August 2009 equinox allows out-of-plane structures and moons orbiting in or near the plane of Saturn's equatorial rings to cast shadows onto the rings. These scenes are possible only during the few months before and after Saturn's equinox, which occurs only once in about 15 Earth years. To learn more about this special time and to see movies of moons' shadows moving across the rings, see PIA11651 and PIA11660.

This view looks toward the northern, unilluminated side of the rings from about 31 degrees above the ringplane. Many stars are visible. The rings and stars have been brightened by a factor six relative to Prometheus to enhance visibility.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 29, 2009. The view was acquired at a distance of approximately 1.4 million kilometers (870,000 miles) from Prometheus and at a Sun-Prometheus-spacecraft, or phase, angle of 93 degrees. Image scale is 9 kilometers (6 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute

Note: The photo also shows several streamer channels and gravitational perturbations in the F-Ring. For more on this topic, see Fleeing the Scene and Fan Structures in Saturn's F-Ring.

Prometheus and the Rings

Saturn's small, potato-shaped moon Prometheus orbits between the main rings and the thin F ring in this Cassini spacecraft view.

Prometheus can be seen just above the center of the image as it orbits in the Roche Division. The gravitational influence of Prometheus (86 kilometers, or 53 miles across) periodically creates streamer-channels in the F ring. To learn more and to watch a movie of this process, see PIA08397.

This view looks toward the northern, sunlit side of the rings from just above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 15, 2010. The view was acquired at a distance of approximately 2.6 million kilometers (1.6 million miles) from Prometheus. Image scale is 15 kilometers (9 miles) per pixel.

Photo credit: NASA/JPL/Space Science Institute