Jupiter's main ring is a narrow structure about 6,000 kilometers (about 3,700 miles) in width and about 100,000 times fainter than the planet it encircles. These are the first pictures that NASA's Cassini spacecraft has taken of the ring, a portion of which appears in each frame as an arc opening toward the right.

Image processing helped make the ring easier to see in these frames taken with Cassini's narrow-angle camera during a 39.5-hour period beginning Dec. 11, 2000. The distance between the spacecraft and Jupiter narrowed during those hours, from 20.3 million kilometers (12.6 million miles) to 19 million kilometers (11.8 million miles). Also, Cassini's movement took it from 3.3 degrees above the plane of the rings to 2.98 degrees above the plane. The frames are in sequence from upper left to lower right. The image of the ring's arc grows longer, as the spacecraft approaches the planet.

Resolution is about 230 kilometers (143 miles) per pixel. The 10 frames shown here are each a small section of several separate narrow-angle images taken through the camera's clear filter and spanning the entire 39.5 hour period. The scattered light background has been removed, and the images have been contrast-stretched to enhance the ring. The contours in the image, as well as the small variations in brightness of the ring from one frame to the next, are a result of the image processing and background removal.

This image sequence also shows the motions of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies. This image sequence also shows the motions of two satellites embedded in Jupiter's ring. The moon Adrastea is the fainter of the two, and Metis the brighter. Images such as these will be used to refine the orbits of the two bodies.

Cassini 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 mission for NASA's Office of Space Science, Washington, D.C.