The Cassini spacecraft captured the closest images of Saturn's moon Daphnis on July 5, 2010. The moon can be seen orbiting in a rift known as the Keeler Gap in one of Saturn's rings.
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This image shows long shadows cast by distortions on the edge the A ring created by the gravity of the moon Daphnis. The image was taken in visible light by the Cassini spacecraft on the 28th July, 2009, shortly before Saturn's August 2009 equinox.
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Daphnis is seen as the bright dot in the Keeler Gap near the disruption at the bottom of the image. The moon is approximately 983,000 kilometres away from the Cassini spacecraft. The Image scale is 6 kilometres per pixel.
Saturn's approach to equinox reveals never-before-seen vertical structures in planet's rings In images made possible only as Saturn nears equinox, NASA's Cassini spacecraft has uncovered towering vertical structures in the planet's otherwise flat rings that are attributable to the gravitational effects of a small nearby moon. The search for ring material extending well above and below Saturn's ring plane has been a major goal of the imaging team during Cassini's "Equinox Mission," the 2-year period containing exact equinox - the moment when the Sun is seen directly overhead at noon at the planet's equator. This novel illumination geometry, which occurs every half-Saturn-year, or about 15 Earth years, lowers the Sun's angle to the ring plane and causes out-of-plane structures to cast long shadows across the rings' broad expanse, making them easy to detect.
This image shows Saturn's moon Daphnis through the A ring from about 47 degrees above the ringplane. Perturbed particles forming wavelike patterns mark both sides of the Keeler gap in which the moon orbits.
Expand (85kb, 908 x 1017) Credit: NASA/JPL/Space Science Institute
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on the 21st February, 2009, when the spacecraft was approximately 1.1 million kilometres from Daphnis and phase angle of 50 degrees. Image scale is 7 kilometres per pixel.
This view offers a detailed look at the faint rings within the Cassini Division as well as a glimpse of the Keeler gap moon, Daphnis. The small, ring embedded moon is a bright unresolved speck above centre, near the outer edge of the A ring.
Discovered in Cassini images in 2005, Daphnis is a mere 7 kilometres across.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 20, 2006, at a distance of approximately 483,000 kilometres from Saturn. The image scale on the sky at the distance of Daphnis is about 2 kilometres per pixel.
Daphnis was discovered on May 1, 2005 by the Cassini Imaging Science Team. The name comes from the shepherd, pipes player, and pastoral poet in Greek mythology. Daphnis was the son of Hermes, brother of Pan, and descendant of the Titans.
The 7 kilometres diameter moon orbits in the Keeler gap in Saturn's A ring, with a orbital radius of 136,500 kilometres. It has an orbital period of 0.594 days. Like Pan, Daphnis was discovered on the basis of the wavy features it excites in the edges of a gap within Saturn's A ring.
The A ring is the outermost of the two largest, brightest rings. Its inner boundary is the Cassini Division and its sharp outer boundary is the orbit of the small moon Atlas. The A Ring is divided in two near its outer edge by the Encke Division which is caused by the presence of the small moon Pan. A smaller, fainter division is called the Keeler Gap, and is kept clear by the moonlet Daphnis.