关于这张图
In reality, Janus and the rings both orbit Saturn and are only weakly connected to each other through their mutual gravitational tugs. At specific locations in the rings, these gravitational tugs result in orbital resonances, which lead to some beautiful waves being created in the rings. See PIA10452 for an example. Janus is 111 miles, or 179 kilometers, across. This view looks toward the sunlit side of the rings from about 19 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 5, 2014. The view was acquired at a distance …
