Cassini sees one of Saturn's moons making waves in its rings
As it nears the end of its mission, NASA's Cassini spacecraft has been going in to get close-ups of Saturn's rings. On January 16 it captured the closest view ever taken of the giant planet's so-called "wavemaker" moon, Daphnis.
The tiny moon is only 5 miles (8 km) across and orbits Saturn in between the rings in an area called the Keeler Gap. The gap is actually 26 miles (42 km) wide, but the angle from which Cassini took the shot at a distance of 17,000 miles (28,000 kilometers) makes it appear much more narrow.
Although Daphnis is small, its gravity still raises "waves" in the edges of the gap, both horizontally and vertically. This new photo demonstrates the effect in the horizontal plane, while earlier images from Cassini in 2009 captured Daphnis stirring vertical waves in the rings.
A faint wisp of ring material is seen trailing just behind the moon and NASA says this may be leftover from a moment when Daphnis pulled a clump of material out of the ring. The edge of one of the ring perturbations also appears a little blurry at one point, which could indicate that the moon disturbed and thinned the ring material at that spot.
The close view of Daphnis itself (top) reveals smooth material on its surface that could be an accumulation of tiny particles from the rings. A few craters are also visible.
This latest image is just one of many captured by Cassini in over a decade at work. The spacecraft is going through a series of close passes of Saturn's rings and moons before its long mission comes to an end as it descends into the gas giant's atmosphere in September.