Bright Are Saturn's Moons

The Cassini spacecraft observed three of Saturn's moons set against the darkened night side of the planet in this image from April 2011.

Saturn is present on the left this image but is too dark to see. Rhea (1,528 kilometers, or 949 miles across) is closest to Cassini here and appears largest at the center of the image. Enceladus (504 kilometers, or 313 miles across) is to the right of Rhea. Dione (1,123 kilometers, or 698 miles across) is to the left of Rhea, and is partly obscured by Saturn.

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

Image Credit: NASA/JPL/Space Science Institute

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Rhea's Return

Rhea emerges ... After being occulted by the larger moon Titan.

Occultation is a celestial event in which a larger body covers up a distant object. Observations such as this one, in which one moon passes close to or in front of another, help scientists refine their understanding of the orbits of Saturn's moons. Titan is about 621,000 miles (1 million kilometers) from Cassini in this image. Rhea is about 1.4 million miles (2.3 million kilometers) from Cassini.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Oct. 27, 2009. Image scale is 4 miles (6 kilometers) per pixel on Titan and 9 miles (14 kilometers) per pixel on Rhea.

Image Credit: NASA/JPL/Space Science Institute

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