As it begins its detailed survey of the Saturn ring region for new moons, Cassini has recovered the tiny moon Atlas, seen here for the first time since Voyager 1 flew past Saturn in 1980.
Cassini's narrow angle camera captured a sequence of 112 images in visible light which were used to create this movie of Atlas and other moons racing around the outer edge of Saturn's rings. Over the course of almost five and one quarter hours, Cassini watched the moons as they circled the planet, snapping 1.2 second exposures about 12 minutes apart. These images were part of a sequence designed specifically to search for small moons near Saturn's F ring. Contrast was enhanced in the images, and the rings themselves intentionally were overexposed, in order to make these small moons visible.
We see a group of three moons rounding the right ansa, followed by a fourth moon. In the first group, the moon exterior to Saturn's thin, knotted F ring is Epimetheus (113 kilometers, 70 miles across); the two moons interior to the F ring are Prometheus (86 kilometers, 53 miles across) and tiny unresolved Atlas (30 kilometers, 19 miles across). Exterior to the F ring and tagging along behind the others, the fourth moon seen here is Pandora (81 kilometers, 50 miles across).
At the same time, on the left side, we see Janus (179 kilometers, 111 miles across). Janus continues in its orbit and reappears on the right side of the movie, while the other quartet of moons soon emerges on the left side. A faint 11th magnitude sta remains at a constant distance from the right ansa.
The view is taken looking upward from Cassini's southern vantage point beneath the ring plane. The moons visible here are orbiting Saturn in a plane that is tilted 67 degrees away from the viewer.
These images were taken on May 26 and 27, 2004 from a distance of approximately 19.2 million kilometers (11.9 million miles) from Saturn. The image scale is approximately 114 kilometers (71 miles) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Office of Space Science, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.