* Astronomy

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Epimetheus

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Saturn's moon Epimetheus discovered. (1966)

Epimetheus is an inner satellite of Saturn. It is also known as Saturn XI. It is named after the mythological Epimetheus, brother of Prometheus.

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This image of Epimetheus was taken by the Cassini Spaceprobe on the 17th January, 2010.

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Credit: NASA/JPL/Space Science Institute

The image was taken using the CL1 and CL2 filters.

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The Cassini spacecraft's close flyby of Epimetheus in December 2007 returned detailed images of the moon's south polar region.

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Credit: NASA/JPL/Space Science Institute

This view shows what might be the remains of a large impact crater covering most of this face, and which could be responsible for the somewhat flattened shape of the southern part of Epimetheus.
The image also shows two terrain types: darker, smoother areas, and brighter, slightly more yellowish, fractured terrain. One interpretation of this image is that the darker material evidently moves down slopes, and probably has a lower ice content than the brighter material, which appears more like "bedrock." Nonetheless, materials in both terrains are likely to be rich in water ice.

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This image of Epimetheus was taken by the Cassini Spaceprobe on December 03, 2007, when it was approximately 37,440 kilometres away.

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Credit: NASA/JPL/Space Science Institute

The image was taken using the CL1 and IR3 filters.

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This image of Epimetheus was taken by the Cassini Spaceprobe on December 03, 2007, when it was approximately 40,388 kilometres away.

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Credit: NASA/JPL/Space Science Institute

The image was taken using the RED and CL2 filters.

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This image of Epimetheus was taken by the Cassini spaceprobes narrow-angle camera on June 1, 2007, when it was approximately 1.9 million kilometres away.

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Credit: NASA/JPL/Space Science Institute

The view looks toward the unilluminated side of the rings from about 7 degrees above the ringplane.
The image was taken in visible light.
Beyond Epimetheus the narrow F-ring appears dark against the clouds on Saturn. The three largest gaps in the rings, (the Keeler, Encke Gaps and Cassini Division), now appear as bright regions in the dark ringplane.

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In their orbital ballet, Janus and Epimetheus swap positions every four years -- one moon moving closer to Saturn, the other moving farther away. The two recently changed positions (the swap occurring on Jan. 21, 2006), and Janus will remain the innermost of the pair until 2010, when they will switch positions again.

Although the moons appear to be close in the image, they are not. Janus (181 kilometres across at right) is about 40,000 kilometres farther away from Cassini than Epimetheus (116 kilometres across, at left) in this view. In fact, even when they are at their closest, tugging at each other and swapping orbital positions, they are never closer than about 15,000 kilometres.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 20, 2006 at a distance of approximately 452,000 kilometres from Epimetheus and 492,000 kilometres from Janus. The image scale is 3 kilometres per pixel on both moons.

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From 34 degrees above Saturn's equatorial plane, Cassini gazed down at Saturn's moon Epimetheus. The region seen here includes territory farther north and east than that imaged in March 2005.

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The two largest craters visible here are the only officially named features on Epimetheus. The crater at the left (at about the 9 o'clock position) is named Pollux; the crater at lower left (containing a string of several smaller craters) is called Hilairea.
Epimetheus is only 116 kilometres across, and does not have enough surface gravity to restructure itself into a sphere.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2005, at a distance of approximately 87,000 kilometres from Epimetheus and at a Sun-Epimetheus-spacecraft, or phase, angle of 95 degrees. The image scale is 520 meters per pixel.

-- Edited by Blobrana at 11:13, 2005-08-24

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This image was taken on July 14, 2005 and received on Earth July 15, 2005. The camera was pointing toward Epimetheus that was approximately 87,709 kilometres away.
The image was taken using the P120 and GRN filters.

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