关于这张图
This image of Saturn's outer A ring features the small moon Daphnis and the waves it raises in the edges of the Keeler Gap. The image was taken by NASA's Cassini spacecraft on Sept. 13, 2017. It is among the last images Cassini sent back to Earth. The view was taken in visible light using the Cassini spacecraft wide-angle camera at a distance of 486,000 miles (782,000 kilometers) from Saturn. Image scale is 2.7 miles (4.3 kilometers). https://photojournal.jpl.nasa.gov/catalog/PIA21893
