Touching Saturn
22 May 2007


Credit: NASA/JPL/Space Science Institute

NASA recently published a fantastic image of Saturn, acquired by the Saturn-bound Cassini spacecraft. The image shows Prometheus, Saturn's tiny, intriguing moon, gliding past the ringed giant.

Irregularly-shaped Prometheus (102 km across) shines as a little streak just below Saturn. It appears as if it were grazing Saturn, while delving into darkness. The F ring is visible as a thin, pale line, extending across lower right.

Cassini was looking down toward the unlit side of the rings, from about 18° above the ringplane. 

Images taken in red, green and blue spectral filters were combined to produce this natural color picture. The images were obtained by Cassini's narrow-angle camera on 13 April 2007. The spacecraft was at a distance of approximately 1.7 million km from Prometheus, and 1.8 million km from Saturn. Image scale is 10 km per pixel.

Prometheus is a shepherd moon of the F ring. A shepherd moon orbits its parent planet inside, or close to one of the planet's rings. The moon's gravity confines and perturbs the ring, and may also distort its shape.

Further Reading

Two Small Moons Align

Cassini-Huygens Mission

Aymen Mohamed Ibrahem

Senior Astronomy Specialist

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