NASA's Saturn probe beams back image of wavemaker moon Daphnis
NASA has released the closest view of Saturn's wavemaker moon, Daphnis, captured as the Cassini spacecraft made one of its ring-grazing passes over the outer edges of the planet's rings.
Daphnis, measuring just eight kilometres across, orbits within the 42-kilometre wide area known as the Keeler Gap.
The little moon's gravity raises waves in the edges of the gap in both the horizontal and vertical directions. Cassini was able to observe the vertical structures in 2009, around the time of Saturn's equinox.
Like a couple of Saturn's other small ring moons, Atlas and Pan, Daphnis appears to have a narrow ridge around its equator and a fairly smooth mantle of material on its surface - likely an accumulation of fine particles from the rings.
A few craters are also visible in the image. An additional ridge can be seen further north that runs parallel to the equatorial band.
Fine details in the rings can also been in the image. In particular, a grainy texture is seen in several wide lanes which hints at structures where particles are clumping together.
In comparison to the otherwise sharp edges of the Keeler Gap, the wave peak in the gap edge at left has a softened appearance.
This is possibly due to the movement of fine ring particles being spread out into the gap following Daphnis' last close approach to that edge on a previous orbit.
A faint, narrow tendril of ring material is seen following just behind Daphnis.
This may have resulted from a moment when Daphnis drew a packet of material out of the ring, and now that packet is spreading itself out.
The image was taken in visible green light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of about 28,000 kilometres from Daphnis.